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标题: 手写SpringMVC底层机制 [打印本页]

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作者: tsx81428    时间: 2024-5-18 06:00
标题: 手写SpringMVC底层机制
手写 SpringMVC 底层机制

• 前景提要：实现的是SpringMVC焦点机制
  
• 对一些细枝末节的代码做了简化，好比字符串的处置惩罚...
  
• 完成哪些机制
  
  
  
  • 机制一： 通过@RequestMapping ，可以标记一个方法，编写路径url，浏览器就能通过url完成调用
    
  • 机制二： 举行依赖注入，使之不须要传统的new 一个对象，而是直接从IOC容器中获得
    
  • 机制三：通过@RequestParam，如果浏览器转达的参数名和目标方法的形参不一致，可以通过value设置举行匹配
    
  • 机制四：在目标方法完成后，跳转到相关页面 请求转发/重定向
    
  • 机制五：在目标方法完成后，通过@Response注解，向浏览器发送JSON格式数据
    
  
  

手写添加配置

思绪

• 须要配置pom.xml的依赖
  
• 须要写一个Servlet 作为前端控制器
  
• 须要配置Web.xml 中的前端控制器 1).url 2）配置spring容器配置文件的classpath：  3)跟随Tomcat 自启动
  
• 须要配置spring容器配置文件
  
• 须要配置spring容器配置文件 扫描的路径
  

实现

• 须要配置pom.xml的依赖
  

1.     <dependency>
2.       <groupId>javax.servlet</groupId>
3.       <artifactId>javax.servlet-api</artifactId>
4.       <version>3.1.0</version>
5.       <scope>provided</scope>
6.    
7.     </dependency>
9.   
10.     <dependency>
11.       <groupId>dom4j</groupId>
12.       <artifactId>dom4j</artifactId>
13.       <version>1.1</version>
14.     </dependency>
16.   
17.     <dependency>
18.       <groupId>org.apache.commons</groupId>
19.       <artifactId>commons-lang3</artifactId>
20.       <version>3.12.0</version>
21.     </dependency>

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• 须要写一个Servlet 作为前端控制器
  

1. public class ZyDispatcherServlet extends HttpServlet {
3.     @Override
4.     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
5. <?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>System.out.println("ZyDispatcherServlet-doPost--");
10.     }
12.     @Override
13.     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
14. <?xml version="1.0" encoding="UTF-8" ?>
15. <beans>
16.    
17.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
18. </beans>System.out.println("ZyDispatcherServlet-doGet--");
19.     }
20. }

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• 须要配置Web.xml 中的前端控制器 1).url 2）配置spring容器配置文件的classpath：  3)跟随Tomcat 自启动
  
• 须要配置spring容器配置文件 扫描的路径
  

1. <servlet>
2.     <servlet-name>ZyDispatcherServlet</servlet-name>
3.     <servlet-class>com.code_study.zyspringmvc.servlet.ZyDispatcherServlet</servlet-class>
4.    
5.    
6.     <init-param>
7.       <param-name>contextConfigLocation</param-name>
8.       <param-value>classpath:zyspringmvc.xml</param-value>
9.     </init-param>
11.    
12.     <load-on-startup>1</load-on-startup>
13.   </servlet>
14.   <servlet-mapping>
15.     <servlet-name>ZyDispatcherServlet</servlet-name>
16.     <url-pattern>/</url-pattern>
17.   </servlet-mapping>

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• 须要配置spring容器配置文件
  

1. <?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>

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完成浏览器可以请求控制层

思绪

• 创建@Controller和本身的Controller
  
• 编写工具类XMLParser，解析spring容器配置文件
  
• 开发本身的 Spring容器，得到扫描类的全路径列表
  
• 开发本身的 前端控制器，实例化对象到容器中
  
• 完成请求的URL和控制器方法的映射关系
  
• 完成前端控制器分发请求到对应控制器
  

• 自定义注解@Controller
  
• 创建Controller
  
• 须要写一个工具类XMLParser来解析在spring容器配置文件 扫描的路径  的包 返回所有的路径
  
• 这个所有的路径 一个split（",")分隔，都举行扫描
  
• 须要写本身的 前端控制器
  
• 须要写本身的 Spring容器
  
• 在前端控制器中 须要添加方法 scanPackage（） 扫描 XMLParser 解析出来的路径
  
• 在Spring容器中 须要添加一个属性 classFullPathList 来保存扫描出来的类的全路径
  
• 须要添加一个属性 ioc 来存放反射生成的bean对象 也就是过滤classFullPathList  中没有@Controller注解的一些路径 并实例化
  
• 须要添加类Handler 这个类要保存 一个url 对应的 一个控制器的方法的 映射 ，也就是说，根据这个url，可以找到对应控制器的对应方法
  
• 须要添加一个属性 HandlerList 用于 保存Handler 【url 和 控制器的映射】
  
• 须要添加三个方法 一个是initHandlerMapping（），完成 url 对应的 一个控制器的方法的 映射，即 将ioc 中bean 中的 方法举行反射，获取url，将 url，method，bean 封装成Handler  放入HandlerList  保存
  
• 添加第二个方法 getHandler（），须要将浏览器发送的request请求中的 uri拿出来，遍历HandlerList  举行配对，如果有 就返回对应的Handler
  
• 添加第三个方法 executeDispatch（），举行分发处置惩罚，须要 调用getHandler（） 获取浏览器发送的request请求 对应的 Handler  ，获取Handler  中的method 举行反射调用，method .invoke() 实现分发请求。
  

实现

• 自定义注解@Controller
  

1. @Target(ElementType.TYPE)
2. @Retention(RetentionPolicy.RUNTIME)
3. @Documented
4. public @interface Controller {
5.     String value() default "";
6. }

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• 创建Controller
  

1. @Controller
2. public class MonsterController {
3. }

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• 须要写一个工具类XMLParser来解析在spring容器配置文件 扫描的路径  的包 返回所有的路径
  

1. public class XMLParser {    public static String getBasePackage(String xmlFile){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>SAXReader saxReader = new SAXReader();<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>ClassLoader classLoader = XMLParser.class.getClassLoader();<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>InputStream resourceAsStream = classLoader.getResourceAsStream(xmlFile);<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>try {<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>    Document document = saxReader.read(resourceAsStream);<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>    Element rootElement = document.getRootElement();<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    Element element = rootElement.element("component-scan");<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>    String basePackage = element.attribute("base-package").getText();<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>    return basePackage;<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans>} catch (DocumentException e) {<?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans>    throw new RuntimeException(e);<?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>}    }}

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• 这个所有的路径 一个split（",")分隔，都举行扫描
  
• 须要写本身的 前端控制器
  
• 须要写本身的 Spring容器
  
• 在前端控制器中 须要添加方法 scanPackage（） 扫描 XMLParser 解析出来的路径
  

1. public void scanPackage(String pack) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>//获得包所在的工作路径 [绝对路径]<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>URL url =<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans><?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>this.getClass().getClassLoader().//获取类的加载器<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans><?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans><?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>//得到指定包对应的工作路径 [绝对路径]<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans><?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans><?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans><?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans>getResource("/" + pack.replaceAll("\\.", "/"));<?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>// System.out.println("url= "+url);<?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans>//根据得到的路径，对其举行扫描，把类的全路径 保存到 classFullPathList<?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans>String path = url.getFile();<?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans>//在io中 把目录也是为一个文件<?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans>File file = new File(path);<?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans>//遍历file 【遍历出文件和子目录】<?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans>for (File f : file.listFiles()) {<?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans>    if (f.isDirectory()) {//如果是目录<?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans><?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans>//须要递归扫描 找子目录<?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans><?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans>scanPackage(pack + "." + f.getName());<?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans>    } else {<?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans><?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans>//的确是个文件<?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans><?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans>//扫描到的文件大概是 .class 文件 也大概是其他文件<?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans><?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans>//就算是.class 文件 也须要判定是否须要注入容器 有无加 @Controller注解<?xml version="1.0" encoding="UTF-8" ?>
122. <beans>
123.    
124.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
125. </beans><?xml version="1.0" encoding="UTF-8" ?>
126. <beans>
127.    
128.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
129. </beans>//现在无法拿到注解 由于没法反射 以是先把文件的全路径都保存到 classFullPathList 之后在注入对象到容器时再处置惩罚<?xml version="1.0" encoding="UTF-8" ?>
130. <beans>
131.    
132.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
133. </beans><?xml version="1.0" encoding="UTF-8" ?>
134. <beans>
135.    
136.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
137. </beans>String classFullPath =<?xml version="1.0" encoding="UTF-8" ?>
138. <beans>
139.    
140.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
141. </beans><?xml version="1.0" encoding="UTF-8" ?>
142. <beans>
143.    
144.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
145. </beans><?xml version="1.0" encoding="UTF-8" ?>
146. <beans>
147.    
148.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
149. </beans>//类的全路径不须要.class 去掉.class<?xml version="1.0" encoding="UTF-8" ?>
150. <beans>
151.    
152.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
153. </beans><?xml version="1.0" encoding="UTF-8" ?>
154. <beans>
155.    
156.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
157. </beans><?xml version="1.0" encoding="UTF-8" ?>
158. <beans>
159.    
160.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
161. </beans>pack + "." + f.getName().replaceAll(".class", "");<?xml version="1.0" encoding="UTF-8" ?>
162. <beans>
163.    
164.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
165. </beans><?xml version="1.0" encoding="UTF-8" ?>
166. <beans>
167.    
168.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
169. </beans>//保存到 classFullPathList<?xml version="1.0" encoding="UTF-8" ?>
170. <beans>
171.    
172.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
173. </beans><?xml version="1.0" encoding="UTF-8" ?>
174. <beans>
175.    
176.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
177. </beans>classFullPathList.add(classFullPath);<?xml version="1.0" encoding="UTF-8" ?>
178. <beans>
179.    
180.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
181. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
182. <beans>
183.    
184.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
185. </beans>}    }

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• 在Spring容器中 须要添加一个属性 classFullPathList 来保存扫描出来的类的全路径
  

1. //保存扫描的包/子包类的全路径    private List classFullPathList =<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>    new ArrayList();

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• 须要添加一个属性 ioc 来存放反射生成的bean对象 也就是过滤classFullPathList  中没有@Controller注解的一些路径 并实例化
  

1. //定义属性 ioc -> 存放反射生成的bean对象 好比Controller / Service /Daopublic ConcurrentHashMap ioc =<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>new ConcurrentHashMap();

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• 编写方法，将扫描到的类，在满意情况下 反射到ioc容器
  

1. //编写方法，将扫描到的类，在满意情况下 反射到ioc容器    public void executeInstance() {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>if (classFullPathList.size() == 0) {<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>    //说明没有扫描到类<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>    return;<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>//遍历classFullList<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>for (String classFullPath : classFullPathList) {<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    try {<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans><?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>Class clazz = Class.forName(classFullPath);<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans><?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans>if (clazz.isAnnotationPresent(Controller.class)) {//处置惩罚@Controller<?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans><?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans>    String className = clazz.getSimpleName();<?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans><?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans>    Object instance = clazz.newInstance();<?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans><?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans>    String value = clazz.getAnnotation(Controller.class).value();<?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans><?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans>    if (!"".equals(value)) {<?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans><?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans><?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans>className = value;<?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans><?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans>    } else {<?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans><?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans><?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans>className = StringUtils.uncapitalize(className);<?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans><?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans><?xml version="1.0" encoding="UTF-8" ?>
122. <beans>
123.    
124.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
125. </beans>    ioc.put(className, instance);<?xml version="1.0" encoding="UTF-8" ?>
126. <beans>
127.    
128.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
129. </beans><?xml version="1.0" encoding="UTF-8" ?>
130. <beans>
131.    
132.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
133. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
134. <beans>
135.    
136.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
137. </beans><?xml version="1.0" encoding="UTF-8" ?>
138. <beans>
139.    
140.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
141. </beans>else if (clazz.isAnnotationPresent(Service.class)) {//处置惩罚@Service<?xml version="1.0" encoding="UTF-8" ?>
142. <beans>
143.    
144.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
145. </beans><?xml version="1.0" encoding="UTF-8" ?>
146. <beans>
147.    
148.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
149. </beans>    String className = clazz.getSimpleName();//类名<?xml version="1.0" encoding="UTF-8" ?>
150. <beans>
151.    
152.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
153. </beans><?xml version="1.0" encoding="UTF-8" ?>
154. <beans>
155.    
156.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
157. </beans>    Service serviceAnnotation = clazz.getAnnotation(Service.class);<?xml version="1.0" encoding="UTF-8" ?>
158. <beans>
159.    
160.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
161. </beans><?xml version="1.0" encoding="UTF-8" ?>
162. <beans>
163.    
164.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
165. </beans>    String value = serviceAnnotation.value();<?xml version="1.0" encoding="UTF-8" ?>
166. <beans>
167.    
168.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
169. </beans><?xml version="1.0" encoding="UTF-8" ?>
170. <beans>
171.    
172.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
173. </beans>    if (!"".equals(value)) {<?xml version="1.0" encoding="UTF-8" ?>
174. <beans>
175.    
176.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
177. </beans><?xml version="1.0" encoding="UTF-8" ?>
178. <beans>
179.    
180.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
181. </beans><?xml version="1.0" encoding="UTF-8" ?>
182. <beans>
183.    
184.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
185. </beans>className = value;<?xml version="1.0" encoding="UTF-8" ?>
186. <beans>
187.    
188.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
189. </beans><?xml version="1.0" encoding="UTF-8" ?>
190. <beans>
191.    
192.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
193. </beans><?xml version="1.0" encoding="UTF-8" ?>
194. <beans>
195.    
196.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
197. </beans>Object instance = clazz.newInstance();<?xml version="1.0" encoding="UTF-8" ?>
198. <beans>
199.    
200.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
201. </beans><?xml version="1.0" encoding="UTF-8" ?>
202. <beans>
203.    
204.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
205. </beans><?xml version="1.0" encoding="UTF-8" ?>
206. <beans>
207.    
208.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
209. </beans>ioc.put(className, instance);                                }<?xml version="1.0" encoding="UTF-8" ?>
210. <beans>
211.    
212.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
213. </beans>    } catch (Exception e) {<?xml version="1.0" encoding="UTF-8" ?>
214. <beans>
215.    
216.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
217. </beans><?xml version="1.0" encoding="UTF-8" ?>
218. <beans>
219.    
220.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
221. </beans>throw new RuntimeException(e);<?xml version="1.0" encoding="UTF-8" ?>
222. <beans>
223.    
224.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
225. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
226. <beans>
227.    
228.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
229. </beans>}    }

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• 须要添加类Handler 这个类要保存 一个url 对应的 一个控制器的方法的 映射 ，也就是说，根据这个url，可以找到对应控制器的对应方法
  

1. ZyHandler {    private String url;    private Method method;    private Object controller;    public ZyHandler() {    }    public ZyHandler(String url, Method method, Object controller) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>this.url = url;<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>this.method = method;<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>this.controller = controller;    }//须要提供getter和setter方法...

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• 须要添加一个属性 HandlerList 用于 保存Handler 【url 和 控制器的映射】
  

1. //定义属性 HandlerList -> 保存ZyHandler 【url 和 控制器的映射】    private List HandlerList =<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>    new ArrayList();

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• 须要添加三个方法 一个是initHandlerMapping（），完成 url 对应的 一个控制器的方法的 映射，即 将ioc 中bean 中的 方法举行反射，获取url，将 url，method，bean 封装成Handler  放入HandlerList  保存
  

1. private void initHandlerMapping(){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>//遍历 ioc<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>for (Map.Entry entry:  zyWebApplicationContext.ioc.entrySet()) {<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>    if (zyWebApplicationContext.ioc.isEmpty()){<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans><?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>return;<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    Object bean = entry.getValue();<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>    Class clazz = bean.getClass();<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>    if (clazz.isAnnotationPresent(Controller.class)){<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans><?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans>Method[] declaredMethods = clazz.getDeclaredMethods();<?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans><?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans>for (Method declaredMethod : declaredMethods) {<?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans><?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans>    if (declaredMethod.isAnnotationPresent(RequestMapping.class)){<?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans><?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans><?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans>String url = declaredMethod.getAnnotation(RequestMapping.class).value();<?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans><?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans><?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans>ZyHandler zyHandler = new ZyHandler(url, declaredMethod, bean);<?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans><?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans><?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans>HandlerList.add(zyHandler);<?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans><?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans><?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans>}    }

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• 添加第二个方法 getHandler（），须要将浏览器发送的request请求中的 uri拿出来，遍历HandlerList  举行配对，如果有 就返回对应的Handler
  

1. //编写方法，通过request对象 返回ZyHandler对象 ，如果没有返回null    private ZyHandler getZyHandler(HttpServletRequest request) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>String requestURI = request.getRequestURI();<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>//遍历HandlerList<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>for (ZyHandler zyHandler : HandlerList) {<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>    if (requestURI.equals(zyHandler.getUrl())){<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans><?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>return zyHandler;<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>return null;    }

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• 添加第三个方法 executeDispatch（），举行分发处置惩罚，须要 调用getHandler（） 获取浏览器发送的request请求 对应的 Handler  ，获取Handler  中的method 举行反射调用，method .invoke() 实现分发请求。
  

1.    public void executeDispatch(HttpServletRequest request,HttpServletResponse response){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>ZyHandler zyHandler = getZyHandler(request);<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>try {<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>    if (null == zyHandler){<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>       response.getWriter().write("[size=6]404 NOT FOUND[/size]
19. ");<?xml version="1.0" encoding="UTF-8" ?>
20. <beans>
21.    
22.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
23. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
24. <beans>
25.    
26.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
27. </beans>    Method method = zyHandler.getMethod();<?xml version="1.0" encoding="UTF-8" ?>
28. <beans>
29.    
30.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
31. </beans>    method.invoke(zyHandler.getController(),request,response);<?xml version="1.0" encoding="UTF-8" ?>
32. <beans>
33.    
34.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
35. </beans>} catch (Exception e) {<?xml version="1.0" encoding="UTF-8" ?>
36. <beans>
37.    
38.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
39. </beans>    throw new RuntimeException(e);<?xml version="1.0" encoding="UTF-8" ?>
40. <beans>
41.    
42.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
43. </beans>}    }

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从web.xml文件中动态获取spring配置文件

思绪

• 首先，我们本身写的前端控制器是一个Servlet，它有 servletConfig，可以servletConfig.getInitParameter("xxx") 来获取之前在web.xml配置的classpath：
  
• 工具类XMLParser 是在spring容器中解析的 ，web.xml配置的classpath： 是在前端控制器中获取的，因此须要spring容器提供有参构造器，在前端控制器添加参数 spring容器，将classpath 传到spring容器中举行解析。
  

实现

• 首先，我们本身写的前端控制器是一个Servlet，它有 servletConfig，可以servletConfig.getInitParameter("xxx") 来获取之前在web.xml配置的classpath：
  
• 工具类XMLParser 是在spring容器中解析的 ，web.xml配置的classpath： 是在前端控制器中获取的，因此须要spring容器提供有参构造器，在前端控制器添加参数 spring容器，将classpath 传到spring容器中举行解析。
  

1. @Override    public void init() throws ServletException {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>String configLocation = getServletConfig().getInitParameter("contextConfigLocation");<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>System.out.println("ZyDispatcherServlet 初始化---");<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>zyWebApplicationContext = new ZyWebApplicationContext(configLocation);<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>zyWebApplicationContext.init();<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>initHandlerMapping();<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>System.out.println("HandlerList= "+HandlerList);    }

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1. private  String configLocation;    public ZyWebApplicationContext(String configLocation) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>this.configLocation = configLocation;    }

复制代码

1. public void init(){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>System.out.println("ZyWebApplicationContext 初始化---");<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>String basePackage = XMLParser.getBasePackage(configLocation.split(":")[1]);<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>String[] basePackages = basePackage.split(",");<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>if (basePackages.length >0) {<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>    for (String  pack : basePackages) {<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans><?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>scanPackage(pack);<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>} }

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@Service注解

思绪

• @Service注解是写在类上的 即@Target(ElementType.TYPE)
  
• 这个注解标识的类就是一个Service，那么同样是在executeInstance()方法中判定是否有注解@Service，有的话就保存到ioc容器中
  
• 由于是Service，那么保存进ioc 的 k-v 中的 k 就有三种。第一种，就是默认值，用接口的范例的名字首字母小写；第二种，在@Service注解种设置了value属性，那么 k = value；第三章，须要用类名首字母小写也可以获取bean
  

实现

• @Service注解是写在类上的 即@Target(ElementType.TYPE)
  

1. @Target(ElementType.TYPE)
2. @Retention(RetentionPolicy.RUNTIME)
3. @Documented
4. public @interface Service {
5.     String value() default "";
6. }

复制代码

• 这个注解标识的类就是一个Service，那么同样是在executeInstance()方法中判定是否有注解@Service，有的话就保存到ioc容器中
  
• 由于是Service，那么保存进ioc 的 k-v 中的 k 就有三种。第一种，就是默认值，用接口的范例的名字首字母小写；第二种，在@Service注解种设置了value属性，那么 k = value；第三章，须要用类名首字母小写也可以获取bean
  

1. public void executeInstance() {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>if (classFullPathList.size() == 0){<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>    return;<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>//遍历 classFullPathList<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>for (String classFullPath : classFullPathList) {<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>    try {<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans><?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>Class clazz = Class.forName(classFullPath);<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans><?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans>if (clazz.isAnnotationPresent(Controller.class)){<?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans><?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>    Controller controller = clazz.getAnnotation(Controller.class);<?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans><?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans>    String value = controller.value();<?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans><?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans>    String className = clazz.getSimpleName();<?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans><?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans>    Object instance = clazz.newInstance();<?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans><?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans>    if ("".equals(value)){<?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans><?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans><?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans>className = StringUtils.uncapitalize(className);<?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans><?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans>    }else {<?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans><?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans><?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans>className = value;<?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans><?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
122. <beans>
123.    
124.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
125. </beans><?xml version="1.0" encoding="UTF-8" ?>
126. <beans>
127.    
128.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
129. </beans>    ioc.put(className,instance);<?xml version="1.0" encoding="UTF-8" ?>
130. <beans>
131.    
132.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
133. </beans><?xml version="1.0" encoding="UTF-8" ?>
134. <beans>
135.    
136.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
137. </beans>} else if (clazz.isAnnotationPresent(Service.class)) {<?xml version="1.0" encoding="UTF-8" ?>
138. <beans>
139.    
140.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
141. </beans><?xml version="1.0" encoding="UTF-8" ?>
142. <beans>
143.    
144.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
145. </beans>    Service serviceAnnotation = clazz.getAnnotation(Service.class);<?xml version="1.0" encoding="UTF-8" ?>
146. <beans>
147.    
148.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
149. </beans><?xml version="1.0" encoding="UTF-8" ?>
150. <beans>
151.    
152.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
153. </beans>    String annoattionValue = serviceAnnotation.value();<?xml version="1.0" encoding="UTF-8" ?>
154. <beans>
155.    
156.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
157. </beans><?xml version="1.0" encoding="UTF-8" ?>
158. <beans>
159.    
160.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
161. </beans>    Object instance = clazz.newInstance();<?xml version="1.0" encoding="UTF-8" ?>
162. <beans>
163.    
164.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
165. </beans><?xml version="1.0" encoding="UTF-8" ?>
166. <beans>
167.    
168.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
169. </beans>    if ("".equals(annoattionValue)){<?xml version="1.0" encoding="UTF-8" ?>
170. <beans>
171.    
172.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
173. </beans><?xml version="1.0" encoding="UTF-8" ?>
174. <beans>
175.    
176.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
177. </beans><?xml version="1.0" encoding="UTF-8" ?>
178. <beans>
179.    
180.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
181. </beans>Class[] interfaces = clazz.getInterfaces();<?xml version="1.0" encoding="UTF-8" ?>
182. <beans>
183.    
184.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
185. </beans><?xml version="1.0" encoding="UTF-8" ?>
186. <beans>
187.    
188.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
189. </beans><?xml version="1.0" encoding="UTF-8" ?>
190. <beans>
191.    
192.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
193. </beans>for (Class anInterface : interfaces) {<?xml version="1.0" encoding="UTF-8" ?>
194. <beans>
195.    
196.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
197. </beans><?xml version="1.0" encoding="UTF-8" ?>
198. <beans>
199.    
200.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
201. </beans><?xml version="1.0" encoding="UTF-8" ?>
202. <beans>
203.    
204.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
205. </beans>    String simpleName = anInterface.getSimpleName();<?xml version="1.0" encoding="UTF-8" ?>
206. <beans>
207.    
208.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
209. </beans><?xml version="1.0" encoding="UTF-8" ?>
210. <beans>
211.    
212.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
213. </beans><?xml version="1.0" encoding="UTF-8" ?>
214. <beans>
215.    
216.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
217. </beans>    simpleName = StringUtils.uncapitalize(simpleName);<?xml version="1.0" encoding="UTF-8" ?>
218. <beans>
219.    
220.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
221. </beans><?xml version="1.0" encoding="UTF-8" ?>
222. <beans>
223.    
224.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
225. </beans><?xml version="1.0" encoding="UTF-8" ?>
226. <beans>
227.    
228.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
229. </beans>    ioc.put(simpleName,instance);<?xml version="1.0" encoding="UTF-8" ?>
230. <beans>
231.    
232.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
233. </beans><?xml version="1.0" encoding="UTF-8" ?>
234. <beans>
235.    
236.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
237. </beans><?xml version="1.0" encoding="UTF-8" ?>
238. <beans>
239.    
240.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
241. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
242. <beans>
243.    
244.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
245. </beans><?xml version="1.0" encoding="UTF-8" ?>
246. <beans>
247.    
248.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
249. </beans><?xml version="1.0" encoding="UTF-8" ?>
250. <beans>
251.    
252.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
253. </beans>//可以通过类名首字母小写<?xml version="1.0" encoding="UTF-8" ?>
254. <beans>
255.    
256.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
257. </beans><?xml version="1.0" encoding="UTF-8" ?>
258. <beans>
259.    
260.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
261. </beans><?xml version="1.0" encoding="UTF-8" ?>
262. <beans>
263.    
264.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
265. </beans>String simpleName = clazz.getSimpleName();<?xml version="1.0" encoding="UTF-8" ?>
266. <beans>
267.    
268.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
269. </beans><?xml version="1.0" encoding="UTF-8" ?>
270. <beans>
271.    
272.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
273. </beans><?xml version="1.0" encoding="UTF-8" ?>
274. <beans>
275.    
276.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
277. </beans>simpleName = StringUtils.uncapitalize(simpleName);<?xml version="1.0" encoding="UTF-8" ?>
278. <beans>
279.    
280.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
281. </beans><?xml version="1.0" encoding="UTF-8" ?>
282. <beans>
283.    
284.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
285. </beans><?xml version="1.0" encoding="UTF-8" ?>
286. <beans>
287.    
288.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
289. </beans>ioc.put(simpleName,instance);<?xml version="1.0" encoding="UTF-8" ?>
290. <beans>
291.    
292.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
293. </beans><?xml version="1.0" encoding="UTF-8" ?>
294. <beans>
295.    
296.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
297. </beans>    }else {<?xml version="1.0" encoding="UTF-8" ?>
298. <beans>
299.    
300.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
301. </beans><?xml version="1.0" encoding="UTF-8" ?>
302. <beans>
303.    
304.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
305. </beans><?xml version="1.0" encoding="UTF-8" ?>
306. <beans>
307.    
308.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
309. </beans>ioc.put(annoattionValue,instance);<?xml version="1.0" encoding="UTF-8" ?>
310. <beans>
311.    
312.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
313. </beans><?xml version="1.0" encoding="UTF-8" ?>
314. <beans>
315.    
316.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
317. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
318. <beans>
319.    
320.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
321. </beans><?xml version="1.0" encoding="UTF-8" ?>
322. <beans>
323.    
324.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
325. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
326. <beans>
327.    
328.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
329. </beans>    } catch (Exception e) {<?xml version="1.0" encoding="UTF-8" ?>
330. <beans>
331.    
332.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
333. </beans><?xml version="1.0" encoding="UTF-8" ?>
334. <beans>
335.    
336.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
337. </beans>throw new RuntimeException(e);<?xml version="1.0" encoding="UTF-8" ?>
338. <beans>
339.    
340.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
341. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
342. <beans>
343.    
344.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
345. </beans>}    }

复制代码

@Autowried 依赖注入

思绪

• @Autowried注解是用在字段上，通过ioc容器自动装配，因此 @Target(ElementType.FIELD)
  
• 须要遍历ioc中所有的 bean 中的所有字段，来举行判定是否须要自动装配
  
• 通过反射获取字段，判定该字段是否带有@Autowried 注解，有的话就判定value值
  
• value为"",说明按默认规则 用字段范例首字母小写 去ioc容器举行查找，如果没有抛出空指针异常throw new NullPointerException("ioc 没有该bean")；
  
• 如果有值，去ioc容器举行查找该值对应的bean，如果没有抛出空指针异常throw new NullPointerException("ioc 没有该bean")；如果有该bean，就用该字段的set()方法将本身的bean 和 查找ioc获取的bean举行装配
  
• 即 declaredField.set(bean, beanInIOC);
  
• 由于字段是私有属性private,须要暴力破解declaredField.setAccessible(true);
  

实现

• @Autowried注解是用在字段上，通过ioc容器自动装配，因此 @Target(ElementType.FIELD)
  

1. @Target(ElementType.FIELD)
2. @Retention(RetentionPolicy.RUNTIME)
3. @Documented
4. public @interface Autowired {
5.     String value() default "";
6. }

复制代码

• 须要遍历ioc中所有的 bean 中的所有字段，来举行判定是否须要自动装配
  
• 通过反射获取字段，判定该字段是否带有@Autowried 注解，有的话就判定value值
  
• value为"",说明按默认规则 用字段范例首字母小写 去ioc容器举行查找，如果没有抛出空指针异常throw new NullPointerException("ioc 没有该bean")；
  
• 如果有值，去ioc容器举行查找该值对应的bean，如果没有抛出空指针异常throw new NullPointerException("ioc 没有该bean")；如果有该bean，就用该字段的set()方法将本身的bean 和 查找ioc获取的bean举行装配
  
• 即 declaredField.set(bean, beanInIOC);
  
• 由于字段是私有属性private,须要暴力破解declaredField.setAccessible(true);
  

1. public void  executeAutoWired(){    //遍历ioc    if (ioc.isEmpty()){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>return;    }    //获取容器里的所有bean 以及 bean对应的字段    for (Map.Entry entry : ioc.entrySet()) {<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>Object bean = entry.getValue();<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>Class clazz = bean.getClass();<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>Field[] declaredFields = clazz.getDeclaredFields();<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>for (Field declaredField : declaredFields) {<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>    //通过反射获取字段，判定该字段是否带有@Autowried 注解，有的话就判定value值<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    if (declaredField.isAnnotationPresent(Autowired.class)){<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans><?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>Autowired annotation =<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans><?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans><?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>declaredField.getAnnotation(Autowired.class);<?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans><?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans>String beanName = annotation.value();<?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans><?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans>try {<?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans><?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans>    //value为"",说明按默认规则 用字段范例首字母小写 去ioc容器举行查找，<?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans><?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans>    if ("".equals(beanName)){<?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans><?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans><?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans>beanName = declaredField.getType().getSimpleName();<?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans><?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans><?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans>beanName = StringUtils.uncapitalize(beanName);<?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans><?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans><?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans><?xml version="1.0" encoding="UTF-8" ?>
122. <beans>
123.    
124.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
125. </beans>Object iocBean = ioc.get(beanName);<?xml version="1.0" encoding="UTF-8" ?>
126. <beans>
127.    
128.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
129. </beans><?xml version="1.0" encoding="UTF-8" ?>
130. <beans>
131.    
132.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
133. </beans>    //如果没有抛出空指针异常<?xml version="1.0" encoding="UTF-8" ?>
134. <beans>
135.    
136.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
137. </beans><?xml version="1.0" encoding="UTF-8" ?>
138. <beans>
139.    
140.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
141. </beans><?xml version="1.0" encoding="UTF-8" ?>
142. <beans>
143.    
144.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
145. </beans>if (null == iocBean){<?xml version="1.0" encoding="UTF-8" ?>
146. <beans>
147.    
148.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
149. </beans><?xml version="1.0" encoding="UTF-8" ?>
150. <beans>
151.    
152.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
153. </beans><?xml version="1.0" encoding="UTF-8" ?>
154. <beans>
155.    
156.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
157. </beans>    throw new NullPointerException("ioc 没有该Bean");<?xml version="1.0" encoding="UTF-8" ?>
158. <beans>
159.    
160.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
161. </beans><?xml version="1.0" encoding="UTF-8" ?>
162. <beans>
163.    
164.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
165. </beans><?xml version="1.0" encoding="UTF-8" ?>
166. <beans>
167.    
168.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
169. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
170. <beans>
171.    
172.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
173. </beans><?xml version="1.0" encoding="UTF-8" ?>
174. <beans>
175.    
176.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
177. </beans><?xml version="1.0" encoding="UTF-8" ?>
178. <beans>
179.    
180.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
181. </beans>declaredField.setAccessible(true);//暴力破解<?xml version="1.0" encoding="UTF-8" ?>
182. <beans>
183.    
184.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
185. </beans><?xml version="1.0" encoding="UTF-8" ?>
186. <beans>
187.    
188.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
189. </beans><?xml version="1.0" encoding="UTF-8" ?>
190. <beans>
191.    
192.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
193. </beans>declaredField.set(bean,iocBean);<?xml version="1.0" encoding="UTF-8" ?>
194. <beans>
195.    
196.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
197. </beans><?xml version="1.0" encoding="UTF-8" ?>
198. <beans>
199.    
200.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
201. </beans>} catch (IllegalAccessException e) {<?xml version="1.0" encoding="UTF-8" ?>
202. <beans>
203.    
204.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
205. </beans><?xml version="1.0" encoding="UTF-8" ?>
206. <beans>
207.    
208.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
209. </beans>    throw new RuntimeException(e);<?xml version="1.0" encoding="UTF-8" ?>
210. <beans>
211.    
212.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
213. </beans><?xml version="1.0" encoding="UTF-8" ?>
214. <beans>
215.    
216.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
217. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
218. <beans>
219.    
220.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
221. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
222. <beans>
223.    
224.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
225. </beans>}    }}

复制代码

@RequestParam

思绪

• @RequestParam 是写在PARAMETER上的 也就是说 @Target(ElementType.PARAMETER)
  
• 这个注解实现的功能 大方向是 分发请求 也就是说 写在 executeDispatch()方法中的
  
• 要实现 @RequestParam 须要将形参列表封装到一个数组中 ， 由于反射 invoke 可以传入一个数组作为可变参数解析
  
• 那么就须要两个数组 一个数组是新创建的数组（大小应与，目标数组的形参个数一致） 将实参放入进去 ；另一个是 反射拿到的目标方法的形参的数组
  
• 这两个数组的内容须要一一对应，由于反射须要顺序一致
  
• 须要获取到request 中请求的参数Map 获取参数名和参数值
  
• 可以将功能具体化到 完成这个新数组的实参填写 【完成新数组之后放入invoke方法举行反射就行】
  
• 将步调拆解成 1）完成HttpServletRequest 和 HttpServletResponse 的填写 ；2）完成带有@RequestParam注解的形参的填写；3）完成平凡的方法参数没有@RequestParam注解的形参的填写
  
• 完成HttpServletRequest 和 HttpServletResponse 的填写：就须要先拿到目标方法的所有参数。根据范例的名称 和 形参列表举行匹配 填写
  
• 完成带有@RequestParam注解的形参的填写：须要添加方法，获取目标方法中 带有@RequestParam注解的形参是属于第几个参数的，返回int 代表第几个参数，如果有@RequestParam注解，就会返回相应的索引，如果没有就会返回-1 举行平凡方法参数的填写 处置惩罚
  
• 平凡方法参数的 填写：须要添加方法，将目标方法的所有的形参的名称 反射保存到 List 返回，再通过遍历判定 请求的参数名  和 List中一致的 填写到 数组中
  
• 平凡方法参数的 填写 须要插件，使用java8的特性 解决在默认情况下 parameter.getName() 获取的名字不是形参真正的名字，而是[arg0,arg1,arg2...]的问题
  

实现

• @RequestParam 是写在PARAMETER上的 也就是说 @Target(ElementType.PARAMETER)
  

1. @Target(ElementType.PARAMETER)
2. @Retention(RetentionPolicy.RUNTIME)
3. @Documented
4. public @interface RequestParam {
5.     String value() default "";
6. }

复制代码

• 这个注解实现的功能 大方向是 分发请求 也就是说 写在 executeDispatch()方法中的
  
• 要实现 @RequestParam 须要将形参列表封装到一个数组中 ， 由于反射 invoke 可以传入一个数组作为可变参数解析
  

1. Method method = zyHandler.getMethod();
2. Class<?>[] parameterTypes = method.getParameterTypes();//形参数组
3. Object[] params = new Object[parameterTypes.length];

复制代码

• 那么就须要两个数组 一个数组是新创建的数组（大小应与，目标数组的形参个数一致） 将实参放入进去 ；另一个是 反射拿到的目标方法的形参的数组
  
• 这两个数组的内容须要一一对应，由于反射须要顺序一致
  
• 须要获取到request 中请求的参数Map 获取参数名和参数值
  

1. request.setCharacterEncoding("utf-8");
2. Map<String, String[]> parameterMap = request.getParameterMap();
3. for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
4.     String name = entry.getKey();//参数 键
5.     String value = entry.getValue()[0];//参数 值

复制代码

• 可以将功能具体化到 完成这个新数组的实参填写 【完成新数组之后放入invoke方法举行反射就行】
  
• 将步调拆解成 1）完成HttpServletRequest 和 HttpServletResponse 的填写 ；2）完成带有@RequestParam注解的形参的填写；3）完成平凡的方法参数没有@RequestParam注解的形参的填写
  
• 完成HttpServletRequest 和 HttpServletResponse 的填写：就须要先拿到目标方法的所有参数。根据范例的名称 和 形参列表举行匹配 填写
  

1. for (int i = 0; i < parameterTypes.length; i++) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans><?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>    Class parameterType = parameterTypes[i];<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans><?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>    if ("HttpServletRequest".equals(parameterType.getSimpleName())) {<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans><?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans><?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>params[i] = request;<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans><?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>    } else if ("HttpServletResponse".equals(parameterType.getSimpleName())) {<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans><?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans><?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>params[i] = response;<?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans><?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans><?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans>}

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• 完成带有@RequestParam注解的形参的填写：须要添加方法，获取目标方法中 带有@RequestParam注解的形参是属于第几个参数的，返回int 代表第几个参数，如果有@RequestParam注解，就会返回相应的索引，如果没有就会返回-1 举行平凡方法参数的填写 处置惩罚
  

1. //获取目标方法中 带有@RequestParam注解的形参是属于第几个参数的，返 private int getRequestParamterIndex(Method method,String name){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>    Parameter[] parameters = method.getParameters();<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>    for (int i = 0; i < parameters.length; i++) {<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans><?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>Parameter parameter = parameters[i];<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans><?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>if (parameter.isAnnotationPresent(RequestParam.class)) {<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans><?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>    String value = parameter.getAnnotation(RequestParam.class).value();<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans><?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans>    if (name.equals(value)) {<?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans><?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans><?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans>return i;//返回int 代表第几个参数<?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans><?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans><?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans>return -1;    }

复制代码

1. int requestParamterIndex = getRequestParamterIndex(zyHandler.getMethod(), name);<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans><?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>    if (requestParamterIndex != -1) {<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans><?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans><?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>params[requestParamterIndex] = value;<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans><?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    }

复制代码

• 平凡方法参数的 填写：须要添加方法，将目标方法的所有的形参的名称 反射保存到 List 返回，再通过遍历判定 请求的参数名  和 List中一致的 填写到 数组中
  

1.         //将目标方法的所有的形参的名称 反射保存到 List 返回    private List getParameterNames(Method method){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>List parameterList = new ArrayList();<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>//获取到所有的参数名称<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>Parameter[] parameters = method.getParameters();<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>for (Parameter parameter : parameters) {<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>    //在默认情况下 parameter.getName() 获取的名字不是形参真正的名字<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>    //而是[arg0,arg1,arg2...]<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>    //须要插件，使用java8的特性 解决<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans>    String name = parameter.getName();<?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>    parameterList.add(name);<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans>System.out.println("目标方法的形参列表=" + parameterList);<?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>return parameterList;    }

复制代码

1. else {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans><?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans><?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>//没找到@RequestParam 对应参数--使用默认机制<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans><?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans><?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>//1. 得到目标方法的所有形参名<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans><?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans><?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans>//2. 对得到目标方法的所有形参名举行遍历，<?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans><?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans><?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans>//如果匹配就把当前请求的参数值放入params<?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans><?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans><?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans>List parameterNames = getParameterNames(zyHandler.getMethod());<?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans><?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans><?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans>for (int i = 0; i < parameterNames.size(); i++) {<?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans><?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans><?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans>    if (name.equals(parameterNames.get(i))) {<?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans><?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans><?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans><?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans>params[i] = value;<?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans><?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans><?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans><?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans>break;<?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans><?xml version="1.0" encoding="UTF-8" ?>
122. <beans>
123.    
124.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
125. </beans><?xml version="1.0" encoding="UTF-8" ?>
126. <beans>
127.    
128.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
129. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
130. <beans>
131.    
132.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
133. </beans><?xml version="1.0" encoding="UTF-8" ?>
134. <beans>
135.    
136.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
137. </beans><?xml version="1.0" encoding="UTF-8" ?>
138. <beans>
139.    
140.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
141. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
142. <beans>
143.    
144.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
145. </beans><?xml version="1.0" encoding="UTF-8" ?>
146. <beans>
147.    
148.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
149. </beans>    }

复制代码

• 平凡方法参数的 填写 须要插件，使用java8的特性 解决在默认情况下 parameter.getName() 获取的名字不是形参真正的名字，而是[arg0,arg1,arg2...]的问题
  

1. <?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>    com.fasterxml.jackson.core      jackson-databind      2.14.0   

复制代码

• 完备代码
  

1. public void executeDispatch(HttpServletRequest request, HttpServletResponse response) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>ZyHandler zyHandler = getZyHandler(request);<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>try {<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>    if (null == zyHandler) {<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans><?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>response.getWriter().write("[size=6]404 NOT FOUND![/size]
23. ");<?xml version="1.0" encoding="UTF-8" ?>
24. <beans>
25.    
26.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
27. </beans>    } else {<?xml version="1.0" encoding="UTF-8" ?>
28. <beans>
29.    
30.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
31. </beans><?xml version="1.0" encoding="UTF-8" ?>
32. <beans>
33.    
34.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
35. </beans>Method method = zyHandler.getMethod();<?xml version="1.0" encoding="UTF-8" ?>
36. <beans>
37.    
38.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
39. </beans><?xml version="1.0" encoding="UTF-8" ?>
40. <beans>
41.    
42.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
43. </beans>Class[] parameterTypes = method.getParameterTypes();//形参数组<?xml version="1.0" encoding="UTF-8" ?>
44. <beans>
45.    
46.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
47. </beans><?xml version="1.0" encoding="UTF-8" ?>
48. <beans>
49.    
50.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
51. </beans>Object[] params = new Object[parameterTypes.length];<?xml version="1.0" encoding="UTF-8" ?>
52. <beans>
53.    
54.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
55. </beans><?xml version="1.0" encoding="UTF-8" ?>
56. <beans>
57.    
58.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
59. </beans>//遍历 parameterTypes<?xml version="1.0" encoding="UTF-8" ?>
60. <beans>
61.    
62.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
63. </beans><?xml version="1.0" encoding="UTF-8" ?>
64. <beans>
65.    
66.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
67. </beans>//获取 HttpServletRequest , HttpServletResponse 在形参数组中的位置<?xml version="1.0" encoding="UTF-8" ?>
68. <beans>
69.    
70.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
71. </beans><?xml version="1.0" encoding="UTF-8" ?>
72. <beans>
73.    
74.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
75. </beans>//将request 和 response 保存到  params相应的位置上<?xml version="1.0" encoding="UTF-8" ?>
76. <beans>
77.    
78.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
79. </beans><?xml version="1.0" encoding="UTF-8" ?>
80. <beans>
81.    
82.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
83. </beans>for (int i = 0; i < parameterTypes.length; i++) {<?xml version="1.0" encoding="UTF-8" ?>
84. <beans>
85.    
86.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
87. </beans><?xml version="1.0" encoding="UTF-8" ?>
88. <beans>
89.    
90.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
91. </beans>    Class parameterType = parameterTypes[i];<?xml version="1.0" encoding="UTF-8" ?>
92. <beans>
93.    
94.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
95. </beans><?xml version="1.0" encoding="UTF-8" ?>
96. <beans>
97.    
98.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
99. </beans>    if ("HttpServletRequest".equals(parameterType.getSimpleName())) {<?xml version="1.0" encoding="UTF-8" ?>
100. <beans>
101.    
102.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
103. </beans><?xml version="1.0" encoding="UTF-8" ?>
104. <beans>
105.    
106.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
107. </beans><?xml version="1.0" encoding="UTF-8" ?>
108. <beans>
109.    
110.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
111. </beans>params[i] = request;<?xml version="1.0" encoding="UTF-8" ?>
112. <beans>
113.    
114.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
115. </beans><?xml version="1.0" encoding="UTF-8" ?>
116. <beans>
117.    
118.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
119. </beans>    } else if ("HttpServletResponse".equals(parameterType.getSimpleName())) {<?xml version="1.0" encoding="UTF-8" ?>
120. <beans>
121.    
122.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
123. </beans><?xml version="1.0" encoding="UTF-8" ?>
124. <beans>
125.    
126.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
127. </beans><?xml version="1.0" encoding="UTF-8" ?>
128. <beans>
129.    
130.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
131. </beans>params[i] = response;<?xml version="1.0" encoding="UTF-8" ?>
132. <beans>
133.    
134.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
135. </beans><?xml version="1.0" encoding="UTF-8" ?>
136. <beans>
137.    
138.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
139. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
140. <beans>
141.    
142.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
143. </beans><?xml version="1.0" encoding="UTF-8" ?>
144. <beans>
145.    
146.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
147. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
148. <beans>
149.    
150.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
151. </beans><?xml version="1.0" encoding="UTF-8" ?>
152. <beans>
153.    
154.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
155. </beans>//获取request中的<?xml version="1.0" encoding="UTF-8" ?>
156. <beans>
157.    
158.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
159. </beans><?xml version="1.0" encoding="UTF-8" ?>
160. <beans>
161.    
162.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
163. </beans>request.setCharacterEncoding("utf-8");<?xml version="1.0" encoding="UTF-8" ?>
164. <beans>
165.    
166.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
167. </beans><?xml version="1.0" encoding="UTF-8" ?>
168. <beans>
169.    
170.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
171. </beans>Map parameterMap = request.getParameterMap();<?xml version="1.0" encoding="UTF-8" ?>
172. <beans>
173.    
174.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
175. </beans><?xml version="1.0" encoding="UTF-8" ?>
176. <beans>
177.    
178.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
179. </beans>for (Map.Entry entry : parameterMap.entrySet()) {<?xml version="1.0" encoding="UTF-8" ?>
180. <beans>
181.    
182.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
183. </beans><?xml version="1.0" encoding="UTF-8" ?>
184. <beans>
185.    
186.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
187. </beans>    String name = entry.getKey();//参数 键<?xml version="1.0" encoding="UTF-8" ?>
188. <beans>
189.    
190.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
191. </beans><?xml version="1.0" encoding="UTF-8" ?>
192. <beans>
193.    
194.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
195. </beans>    String value = entry.getValue()[0];//参数 值<?xml version="1.0" encoding="UTF-8" ?>
196. <beans>
197.    
198.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
199. </beans><?xml version="1.0" encoding="UTF-8" ?>
200. <beans>
201.    
202.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
203. </beans>    //获取形参数组中 带有@RequestParam 的形参 的位置<?xml version="1.0" encoding="UTF-8" ?>
204. <beans>
205.    
206.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
207. </beans><?xml version="1.0" encoding="UTF-8" ?>
208. <beans>
209.    
210.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
211. </beans>    //将带有@RequestParam 保存到  params相应的位置上<?xml version="1.0" encoding="UTF-8" ?>
212. <beans>
213.    
214.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
215. </beans><?xml version="1.0" encoding="UTF-8" ?>
216. <beans>
217.    
218.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
219. </beans>    int requestParamterIndex = getRequestParamterIndex(zyHandler.getMethod(), name);<?xml version="1.0" encoding="UTF-8" ?>
220. <beans>
221.    
222.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
223. </beans><?xml version="1.0" encoding="UTF-8" ?>
224. <beans>
225.    
226.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
227. </beans>    if (requestParamterIndex != -1) {<?xml version="1.0" encoding="UTF-8" ?>
228. <beans>
229.    
230.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
231. </beans><?xml version="1.0" encoding="UTF-8" ?>
232. <beans>
233.    
234.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
235. </beans><?xml version="1.0" encoding="UTF-8" ?>
236. <beans>
237.    
238.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
239. </beans>params[requestParamterIndex] = value;<?xml version="1.0" encoding="UTF-8" ?>
240. <beans>
241.    
242.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
243. </beans><?xml version="1.0" encoding="UTF-8" ?>
244. <beans>
245.    
246.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
247. </beans>    } else {<?xml version="1.0" encoding="UTF-8" ?>
248. <beans>
249.    
250.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
251. </beans><?xml version="1.0" encoding="UTF-8" ?>
252. <beans>
253.    
254.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
255. </beans><?xml version="1.0" encoding="UTF-8" ?>
256. <beans>
257.    
258.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
259. </beans>//没找到@RequestParam 对应参数--使用默认机制<?xml version="1.0" encoding="UTF-8" ?>
260. <beans>
261.    
262.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
263. </beans><?xml version="1.0" encoding="UTF-8" ?>
264. <beans>
265.    
266.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
267. </beans><?xml version="1.0" encoding="UTF-8" ?>
268. <beans>
269.    
270.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
271. </beans>//1. 得到目标方法的所有形参名<?xml version="1.0" encoding="UTF-8" ?>
272. <beans>
273.    
274.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
275. </beans><?xml version="1.0" encoding="UTF-8" ?>
276. <beans>
277.    
278.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
279. </beans><?xml version="1.0" encoding="UTF-8" ?>
280. <beans>
281.    
282.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
283. </beans>//2. 对得到目标方法的所有形参名举行遍历，<?xml version="1.0" encoding="UTF-8" ?>
284. <beans>
285.    
286.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
287. </beans><?xml version="1.0" encoding="UTF-8" ?>
288. <beans>
289.    
290.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
291. </beans><?xml version="1.0" encoding="UTF-8" ?>
292. <beans>
293.    
294.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
295. </beans>//如果匹配就把当前请求的参数值放入params<?xml version="1.0" encoding="UTF-8" ?>
296. <beans>
297.    
298.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
299. </beans><?xml version="1.0" encoding="UTF-8" ?>
300. <beans>
301.    
302.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
303. </beans><?xml version="1.0" encoding="UTF-8" ?>
304. <beans>
305.    
306.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
307. </beans>List parameterNames = getParameterNames(zyHandler.getMethod());<?xml version="1.0" encoding="UTF-8" ?>
308. <beans>
309.    
310.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
311. </beans><?xml version="1.0" encoding="UTF-8" ?>
312. <beans>
313.    
314.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
315. </beans><?xml version="1.0" encoding="UTF-8" ?>
316. <beans>
317.    
318.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
319. </beans>for (int i = 0; i < parameterNames.size(); i++) {<?xml version="1.0" encoding="UTF-8" ?>
320. <beans>
321.    
322.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
323. </beans><?xml version="1.0" encoding="UTF-8" ?>
324. <beans>
325.    
326.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
327. </beans><?xml version="1.0" encoding="UTF-8" ?>
328. <beans>
329.    
330.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
331. </beans>    if (name.equals(parameterNames.get(i))) {<?xml version="1.0" encoding="UTF-8" ?>
332. <beans>
333.    
334.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
335. </beans><?xml version="1.0" encoding="UTF-8" ?>
336. <beans>
337.    
338.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
339. </beans><?xml version="1.0" encoding="UTF-8" ?>
340. <beans>
341.    
342.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
343. </beans><?xml version="1.0" encoding="UTF-8" ?>
344. <beans>
345.    
346.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
347. </beans>params[i] = value;<?xml version="1.0" encoding="UTF-8" ?>
348. <beans>
349.    
350.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
351. </beans><?xml version="1.0" encoding="UTF-8" ?>
352. <beans>
353.    
354.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
355. </beans><?xml version="1.0" encoding="UTF-8" ?>
356. <beans>
357.    
358.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
359. </beans><?xml version="1.0" encoding="UTF-8" ?>
360. <beans>
361.    
362.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
363. </beans>break;<?xml version="1.0" encoding="UTF-8" ?>
364. <beans>
365.    
366.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
367. </beans><?xml version="1.0" encoding="UTF-8" ?>
368. <beans>
369.    
370.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
371. </beans><?xml version="1.0" encoding="UTF-8" ?>
372. <beans>
373.    
374.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
375. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
376. <beans>
377.    
378.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
379. </beans><?xml version="1.0" encoding="UTF-8" ?>
380. <beans>
381.    
382.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
383. </beans><?xml version="1.0" encoding="UTF-8" ?>
384. <beans>
385.    
386.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
387. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
388. <beans>
389.    
390.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
391. </beans><?xml version="1.0" encoding="UTF-8" ?>
392. <beans>
393.    
394.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
395. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
396. <beans>
397.    
398.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
399. </beans><?xml version="1.0" encoding="UTF-8" ?>
400. <beans>
401.    
402.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
403. </beans>}

复制代码

视图解析

思绪

• 首先 视图解析 它是在分发请求后 在目标方法中举行视图的跳转 forward 大概 redirect，以是这部分的代码应该在 前端处置惩罚器的executeDispatch 中 对目标方法举行反射后调用
  
• 在对目标方法举行反射 method.invoke() 就会有返回值，根据返回值的范例举行相应业务处置惩罚
  
• 当返回的是String范例后 我们就可以根据 splic（":"）举行分隔
  
• splic（":"）[0] 就是举行跳转的方式 forward 大概 redirect
  
• splic（":"）[1] 就是举行跳转的页面
  
• 如果没有":" ，就说明是默认情况，forward 处置惩罚即可
  

实现

• 首先 视图解析 它是在分发请求后 在目标方法中举行视图的跳转 forward 大概 redirect，以是这部分的代码应该在 前端处置惩罚器的executeDispatch 中 对目标方法举行反射后调用
  
• 在对目标方法举行反射 method.invoke() 就会有返回值，根据返回值的范例举行相应业务处置惩罚
  1. Object result = zyHandler.getMethod().invoke(zyHandler.getController(), params);

  复制代码
• 当返回的是String范例后 我们就可以根据 splic（":"）举行分隔
  
• splic（":"）[0] 就是举行跳转的方式 forward 大概 redirect
  
• splic（":"）[1] 就是举行跳转的页面
  
• 如果没有":" ，就说明是默认情况，forward 处置惩罚即可
  

1. if (result instanceof String){<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans><?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>   String viewName =  (String) result;<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans><?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>    if (viewName.contains(":")) {<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans><?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans><?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>String viewType = viewName.split(":")[0];<?xml version="1.0" encoding="UTF-8" ?>
30. <beans>
31.    
32.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
33. </beans><?xml version="1.0" encoding="UTF-8" ?>
34. <beans>
35.    
36.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
37. </beans><?xml version="1.0" encoding="UTF-8" ?>
38. <beans>
39.    
40.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
41. </beans>String viewPage = viewName.split(":")[1];<?xml version="1.0" encoding="UTF-8" ?>
42. <beans>
43.    
44.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
45. </beans><?xml version="1.0" encoding="UTF-8" ?>
46. <beans>
47.    
48.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
49. </beans><?xml version="1.0" encoding="UTF-8" ?>
50. <beans>
51.    
52.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
53. </beans>if ("forward".equals(viewType)){<?xml version="1.0" encoding="UTF-8" ?>
54. <beans>
55.    
56.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
57. </beans><?xml version="1.0" encoding="UTF-8" ?>
58. <beans>
59.    
60.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
61. </beans><?xml version="1.0" encoding="UTF-8" ?>
62. <beans>
63.    
64.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
65. </beans>    request.getRequestDispatcher(viewPage).forward(request,response);<?xml version="1.0" encoding="UTF-8" ?>
66. <beans>
67.    
68.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
69. </beans><?xml version="1.0" encoding="UTF-8" ?>
70. <beans>
71.    
72.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
73. </beans><?xml version="1.0" encoding="UTF-8" ?>
74. <beans>
75.    
76.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
77. </beans>}else if (("redirect".equals(viewType))){<?xml version="1.0" encoding="UTF-8" ?>
78. <beans>
79.    
80.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
81. </beans><?xml version="1.0" encoding="UTF-8" ?>
82. <beans>
83.    
84.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
85. </beans><?xml version="1.0" encoding="UTF-8" ?>
86. <beans>
87.    
88.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
89. </beans>    response.sendRedirect(viewPage);<?xml version="1.0" encoding="UTF-8" ?>
90. <beans>
91.    
92.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
93. </beans><?xml version="1.0" encoding="UTF-8" ?>
94. <beans>
95.    
96.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
97. </beans><?xml version="1.0" encoding="UTF-8" ?>
98. <beans>
99.    
100.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
101. </beans>}<?xml version="1.0" encoding="UTF-8" ?>
102. <beans>
103.    
104.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
105. </beans><?xml version="1.0" encoding="UTF-8" ?>
106. <beans>
107.    
108.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
109. </beans>    }else {<?xml version="1.0" encoding="UTF-8" ?>
110. <beans>
111.    
112.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
113. </beans><?xml version="1.0" encoding="UTF-8" ?>
114. <beans>
115.    
116.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
117. </beans><?xml version="1.0" encoding="UTF-8" ?>
118. <beans>
119.    
120.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
121. </beans>request.getRequestDispatcher(viewName).forward(request,response);<?xml version="1.0" encoding="UTF-8" ?>
122. <beans>
123.    
124.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
125. </beans><?xml version="1.0" encoding="UTF-8" ?>
126. <beans>
127.    
128.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
129. </beans>    }<?xml version="1.0" encoding="UTF-8" ?>
130. <beans>
131.    
132.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
133. </beans><?xml version="1.0" encoding="UTF-8" ?>
134. <beans>
135.    
136.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
137. </beans>}

复制代码

@ResponseBody 返回JSON数据

实现

• 首先@ResponseBody  是写在方法上的 因此 @Target(ElementType.METHOD)
  
• 没有默认值 @ResponseBody仅仅作为一个标识
  
• @ResponseBody它是在分发请求后 在目标方法中标识该方法返回JSON格式的数据给浏览器，以是这部分的代码应该在 前端处置惩罚器的executeDispatch 中 对目标方法举行反射后调用
  
• 在对目标方法举行反射 method.invoke() 就会有返回值，根据返回值的范例举行相应业务处置惩罚
  
• 当返回的是一个聚集范例，并且判定该方法有注解@ResponseBody ，就说明是须要向浏览器返回JSON格式数据
  
• 用jackson 包下的 objectWriter对象的 objectMapper.writeValueAsString（）方法 ，可以很轻松的将聚集转化为JSON举行返回
  
• 不要忘了设置response格式，防止乱码，response.setContentType("text/html;charset=utf-8");
  
• 直接用response.getWriter.writer()将转化后的结果返回给浏览器即可
  

思绪

• 首先@ResponseBody  是写在方法上的 因此 @Target(ElementType.METHOD)
  
• 没有默认值 @ResponseBody仅仅作为一个标识
  

1. @Target(ElementType.METHOD)
2. @Retention(RetentionPolicy.RUNTIME)
3. @Documented
4. public @interface ResponseBody {
5. }

复制代码

• @ResponseBody它是在分发请求后 在目标方法中标识该方法返回JSON格式的数据给浏览器，以是这部分的代码应该在 前端处置惩罚器的executeDispatch 中 对目标方法举行反射后调用
  
• 在对目标方法举行反射 method.invoke() 就会有返回值，根据返回值的范例举行相应业务处置惩罚
  
• 当返回的是一个聚集范例，并且判定该方法有注解@ResponseBody ，就说明是须要向浏览器返回JSON格式数据
  
• 用jackson 包下的 objectWriter对象的 objectMapper.writeValueAsString（）方法 ，可以很轻松的将聚集转化为JSON举行返回
  

1. else if (result instanceof ArrayList) {    if (zyHandler.getMethod().isAnnotationPresent(ResponseBody.class)) {<?xml version="1.0" encoding="UTF-8" ?>
2. <beans>
3.    
4.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
5. </beans>ObjectMapper objectMapper = new ObjectMapper();<?xml version="1.0" encoding="UTF-8" ?>
6. <beans>
7.    
8.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
9. </beans>String json = objectMapper.writeValueAsString(result);<?xml version="1.0" encoding="UTF-8" ?>
10. <beans>
11.    
12.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
13. </beans>response.setContentType("text/html;charset=utf-8");<?xml version="1.0" encoding="UTF-8" ?>
14. <beans>
15.    
16.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
17. </beans>PrintWriter writer = response.getWriter();<?xml version="1.0" encoding="UTF-8" ?>
18. <beans>
19.    
20.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
21. </beans>writer.write(json);<?xml version="1.0" encoding="UTF-8" ?>
22. <beans>
23.    
24.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
25. </beans>writer.flush();<?xml version="1.0" encoding="UTF-8" ?>
26. <beans>
27.    
28.     <component-scan base-package="com.code_study.controller,com.code_study.service"></component-scan>
29. </beans>writer.close();    }}

复制代码

• 不要忘了设置response格式，防止乱码，response.setContentType("text/html;charset=utf-8");
  
• 直接用response.getWriter.writer()将转化后的结果返回给浏览器即可
  

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