SpringMVC-09-文件上传和下载 - ToB企服应用市场:ToB评测及商务社交产业平台

<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.3</version>
</dependency>

复制代码

<bean id="multipartResolver" >
<property name="defaultEncoding" value="utf-8"/>
<property name="maxUploadSize" value="10485760"/>
<property name="maxInMemorySize" value="40960"/>
</bean>

复制代码

<form action="${pageContext.request.contextPath}/upload" enctype="multipart/form-data" method="post">
<p>
<input type="file" name="file"/>
</p>
<p>
<input type="submit" value="upload">
</p>
</form>

复制代码

@Controller
public class FileController {
@Autowired
ServletContext servletContext;
//@RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile 对象
//批量上传CommonsMultipartFile则为数组即可
@RequestMapping("/upload")
public String fileUpload(@RequestParam("file") CommonsMultipartFile file) throws IOException {
//获取文件名
String uploadFileName = file.getOriginalFilename();
//如果文件名为空，直接回到首页！
if ("".equals(uploadFileName)) {
return "redirect:/";
}
System.out.println("上传文件名 : " + uploadFileName);
//获取真实物理路径
String path = servletContext.getRealPath("/upload");
//如果路径不存在，创建一个
File realPath = new File(path);
if (!realPath.exists()) {
realPath.mkdir();
}
System.out.println("上传文件保存地址：" + realPath);
InputStream is = file.getInputStream(); //文件输入流
OutputStream os = new FileOutputStream(new File(realPath, uploadFileName)); //文件输出流
//读取写出
int len = 0;
byte[] buffer = new byte[1024];
while ((len = is.read(buffer)) != -1) {
os.write(buffer, 0, len);
}
os.close();
is.close();
return "redirect:/";
}
/**
* 采用file.transferTo 来保存上传的文件
*/
@RequestMapping("/upload2")
public String fileUpload2(@RequestParam("file") CommonsMultipartFile file) throws IOException {
//获取真实物理路径
String path = servletContext.getRealPath("/upload");
File realPath = new File(path);
if (!realPath.exists()) {
realPath.mkdir();
}
//上传文件地址
System.out.println("上传文件保存地址：" + realPath);
//通过CommonsMultipartFile的方法直接写文件（注意这个时候）
file.transferTo(new File(realPath + "/" + file.getOriginalFilename()));
return "redirect:/";
}
}

复制代码

<p>
<a target="_blank" href="https://www.cnblogs.com/${pageContext.request.contextPath}/download">点击下载</a>
</p>

复制代码

@RequestMapping("/download")
public void downloads(HttpServletResponse response) throws Exception {
//要下载的资源地址
String path = servletContext.getRealPath("/upload");
String fileName = "计算机结构框图.jpg";
//1、设置response 响应头
response.reset(); //设置页面不缓存,清空buffer
response.setCharacterEncoding("UTF-8"); //字符编码
response.setContentType("multipart/form-data"); //多扩展类型表单数据
//设置响应头为附件
response.setHeader("Content-Disposition",
"attachment;fileName=" + URLEncoder.encode(fileName, "UTF-8"));
File file = new File(path, fileName);
//2、读取文件--输入流
InputStream input = new FileInputStream(file);
//3、写出文件--输出流
OutputStream out = response.getOutputStream();
byte[] buff = new byte[1024];
int index = 0;
//4、执行写出操作
while ((index = input.read(buff)) != -1) {
out.write(buff, 0, index);
}
out.close();
input.close();
}

复制代码