Spring MVC 文件上传

<!-- 配置文件上传 -->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">   
        <property name="maxUploadSize"><value>100000</value></property> 
        <property name="defaultEncoding"><value>UTF-8</value></property> 
    </bean> 

package controller;

import java.io.File;
import java.io.IOException;
import java.io.Writer;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import model.User;
import service.inters.UserService;

@Controller
@RequestMapping("/user")
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @RequestMapping(value = "/fileUpload", method = {RequestMethod.POST})
    public void fileUpload(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request, HttpServletResponse response, Writer writer){
        response.addHeader("Access-Control-Allow-Origin", "*");
        
        String projectPath = request.getServletContext().getRealPath("");
        String path = "UploadFile";
        try {
            FileUtils.copyInputStreamToFile(file.getInputStream(), new File(projectPath + path, file.getOriginalFilename()));
            writer.write(path);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
}