Mybatis 插件使用及源码分析 - ToB企服应用市场:ToB评测及商务社交产业平台

/**
* @author <a target="_blank" href="https://www.cnblogs.com/2360564660@qq.com">redwinter</a>
* @since 1.0
**/
@Intercepts({@Signature(
type = StatementHandler.class,
method = "prepare",
args = {Connection.class, Integer.class}
)})
@Slf4j
public class MyPlugin implements Interceptor {
@Override
public Object intercept(Invocation invocation) throws Throwable {
log.info("对方法进行增强....");
return invocation.proceed();
}
@Override
public Object plugin(Object target) {
return Plugin.wrap(target, this);
}
@Override
public void setProperties(Properties properties) {
log.info("获取属性值：{}", properties);
}
}

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<properties resource="db.properties"/>
<settings>
<setting name="logImpl" value="STDOUT_LOGGING" />
<setting name="cacheEnabled" value="true"/>
</settings>
<typeAliases>
<package name="com.redwinter.study.mybatis.model"/>
</typeAliases>
<plugins>
<plugin interceptor="mybatis.plugins.MyPlugin">
<property name="redwinter" value="冬玲"/>
</plugin>
<plugin interceptor="com.github.pagehelper.PageInterceptor">
</plugin>
</plugins>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${name}" />
<property name="password" value="${password}" />
</dataSource>
</environment>
</environments>
<mappers>
<package name="mybatis.mapper"/>
</mappers>
</configuration>

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Setting autocommit to false on JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@1386958]
16:02:38.260 [main] INFO mybatis.plugins.MyPlugin - 对方法进行增强....
==> Preparing: update user set name = ?, age = ? where id = ?
==> Parameters: 李四(String), 19(Integer), 1(Integer)
<== Updates: 1
Committing JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@1386958]
Cache Hit Ratio [mybatis.mapper.UserMapper]: 0.5
16:02:38.303 [main] INFO mybatis.plugins.MyPlugin - 对方法进行增强....
==> Preparing: select * from user where id = ?
==> Parameters: 1(Integer)
<== Columns: id, age, name
<== Row: 1, 19, 李四
<== Total: 1
false

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public SqlSessionFactory build(InputStream inputStream, String environment, Properties properties) {
try {
// 创建一个解析xml的构建器，构造函数中会创建一个Configuration类
XMLConfigBuilder parser = new XMLConfigBuilder(inputStream, environment, properties);
// 解析xml配置
return build(parser.parse());
} catch (Exception e) {
throw ExceptionFactory.wrapException("Error building SqlSession.", e);
} finally {
ErrorContext.instance().reset();
try {
if (inputStream != null) {
inputStream.close();
}
} catch (IOException e) {
// Intentionally ignore. Prefer previous error.
}
}
}

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private XMLConfigBuilder(XPathParser parser, String environment, Properties props) {
super(new Configuration());
ErrorContext.instance().resource("SQL Mapper Configuration");
this.configuration.setVariables(props);
this.parsed = false;
this.environment = environment;
this.parser = parser;
}

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public Configuration() {
// 添加别名
typeAliasRegistry.registerAlias("JDBC", JdbcTransactionFactory.class);
typeAliasRegistry.registerAlias("MANAGED", ManagedTransactionFactory.class);
typeAliasRegistry.registerAlias("JNDI", JndiDataSourceFactory.class);
typeAliasRegistry.registerAlias("POOLED", PooledDataSourceFactory.class);
typeAliasRegistry.registerAlias("UNPOOLED", UnpooledDataSourceFactory.class);
typeAliasRegistry.registerAlias("PERPETUAL", PerpetualCache.class);
typeAliasRegistry.registerAlias("FIFO", FifoCache.class);
typeAliasRegistry.registerAlias("LRU", LruCache.class);
typeAliasRegistry.registerAlias("SOFT", SoftCache.class);
typeAliasRegistry.registerAlias("WEAK", WeakCache.class);
typeAliasRegistry.registerAlias("DB_VENDOR", VendorDatabaseIdProvider.class);
typeAliasRegistry.registerAlias("XML", XMLLanguageDriver.class);
typeAliasRegistry.registerAlias("RAW", RawLanguageDriver.class);
typeAliasRegistry.registerAlias("SLF4J", Slf4jImpl.class);
typeAliasRegistry.registerAlias("COMMONS_LOGGING", JakartaCommonsLoggingImpl.class);
typeAliasRegistry.registerAlias("LOG4J", Log4jImpl.class);
typeAliasRegistry.registerAlias("LOG4J2", Log4j2Impl.class);
typeAliasRegistry.registerAlias("JDK_LOGGING", Jdk14LoggingImpl.class);
typeAliasRegistry.registerAlias("STDOUT_LOGGING", StdOutImpl.class);
typeAliasRegistry.registerAlias("NO_LOGGING", NoLoggingImpl.class);
typeAliasRegistry.registerAlias("CGLIB", CglibProxyFactory.class);
typeAliasRegistry.registerAlias("JAVASSIST", JavassistProxyFactory.class);
languageRegistry.setDefaultDriverClass(XMLLanguageDriver.class);
languageRegistry.register(RawLanguageDriver.class);
}

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private final Map<String, Class<?>> typeAliases = new HashMap<>();
public TypeAliasRegistry() {
// 注册别名，最终全部会注册到Map中
registerAlias("string", String.class);
registerAlias("byte", Byte.class);
registerAlias("char", Character.class);
registerAlias("character", Character.class);
registerAlias("long", Long.class);
registerAlias("short", Short.class);
registerAlias("int", Integer.class);
registerAlias("integer", Integer.class);
registerAlias("double", Double.class);
registerAlias("float", Float.class);
registerAlias("boolean", Boolean.class);
registerAlias("byte[]", Byte[].class);
registerAlias("char[]", Character[].class);
registerAlias("character[]", Character[].class);
registerAlias("long[]", Long[].class);
registerAlias("short[]", Short[].class);
registerAlias("int[]", Integer[].class);
registerAlias("integer[]", Integer[].class);
registerAlias("double[]", Double[].class);
registerAlias("float[]", Float[].class);
registerAlias("boolean[]", Boolean[].class);
registerAlias("_byte", byte.class);
registerAlias("_char", char.class);
registerAlias("_character", char.class);
registerAlias("_long", long.class);
registerAlias("_short", short.class);
registerAlias("_int", int.class);
registerAlias("_integer", int.class);
registerAlias("_double", double.class);
registerAlias("_float", float.class);
registerAlias("_boolean", boolean.class);
registerAlias("_byte[]", byte[].class);
registerAlias("_char[]", char[].class);
registerAlias("_character[]", char[].class);
registerAlias("_long[]", long[].class);
registerAlias("_short[]", short[].class);
registerAlias("_int[]", int[].class);
registerAlias("_integer[]", int[].class);
registerAlias("_double[]", double[].class);
registerAlias("_float[]", float[].class);
registerAlias("_boolean[]", boolean[].class);
registerAlias("date", Date.class);
registerAlias("decimal", BigDecimal.class);
registerAlias("bigdecimal", BigDecimal.class);
registerAlias("biginteger", BigInteger.class);
registerAlias("object", Object.class);
registerAlias("date[]", Date[].class);
registerAlias("decimal[]", BigDecimal[].class);
registerAlias("bigdecimal[]", BigDecimal[].class);
registerAlias("biginteger[]", BigInteger[].class);
registerAlias("object[]", Object[].class);
registerAlias("map", Map.class);
registerAlias("hashmap", HashMap.class);
registerAlias("list", List.class);
registerAlias("arraylist", ArrayList.class);
registerAlias("collection", Collection.class);
registerAlias("iterator", Iterator.class);
registerAlias("ResultSet", ResultSet.class);
}

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public Configuration parse() {
if (parsed) {
throw new BuilderException("Each XMLConfigBuilder can only be used once.");
}
parsed = true;
// 解析配置，从根的configuration的标签开始
parseConfiguration(parser.evalNode("/configuration"));
return configuration;
}
private void parseConfiguration(XNode root) {
try {
// issue #117 read properties first
propertiesElement(root.evalNode("properties"));
Properties settings = settingsAsProperties(root.evalNode("settings"));
loadCustomVfs(settings);
// 加载自定义的日志打印
loadCustomLogImpl(settings);
// 解析别名
typeAliasesElement(root.evalNode("typeAliases"));
// 添加插件
pluginElement(root.evalNode("plugins"));
objectFactoryElement(root.evalNode("objectFactory"));
objectWrapperFactoryElement(root.evalNode("objectWrapperFactory"));
reflectorFactoryElement(root.evalNode("reflectorFactory"));
// 设置默认的配置
settingsElement(settings);
// read it after objectFactory and objectWrapperFactory issue #631
// 解析环境信息
environmentsElement(root.evalNode("environments"));
databaseIdProviderElement(root.evalNode("databaseIdProvider"));
// 解析类型处理器标签
typeHandlerElement(root.evalNode("typeHandlers"));
// 解析mappers标签
mapperElement(root.evalNode("mappers"));
} catch (Exception e) {
throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + e, e);
}
}

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