前台：
1.表单提交方式为post
2.有文件上传输入框<input type="file" name="xxx"这里的name是什么，后台接收的MutipartFile xxx ，名称一致
3.form表单中不许添加entype="mutipart/form-data"
后台
1.导jar包
commons-io.jar
commons-fileupload.jar
2.配置文件上传解析器 （ id 必须为mutipartResolver）
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 设定默认编码 -->
<property name="defaultEncoding" value="UTF-8"/>
</bean>
3.用MutipartFile接收参数，参数名称和input中的name值一致
以下是文件的上传和修改
@RequestMapping("/addProduct.do")
public String addProduct(Product product, MultipartFile file, HttpSession session) throws IOException {
// System.out.println(product.getName());
String path=session.getServletContext().getRealPath("/productImg");
File file1=new File(path);
if(!file1.exists()){
file1.mkdirs();
}
String fileName=System.currentTimeMillis()+"-"+file.getOriginalFilename();
System.out.println(fileName);
file.transferTo(new File(path+File.separator+fileName));
product.setId(IdUtils.getUUID());
product.setImgurl("/productImg/"+fileName);
adminService.addProduct(product);
return "/admin/listProduct.do";
}
@RequestMapping("/editProduct.do")
public String editProduct(Product product,HttpSession session,MultipartFile file) throws IOException {
System.out.println(file.getOriginalFilename());
if(!file.isEmpty()){
String path=session.getServletContext().getRealPath("/productImg");
//String path="D:/idea-workspace/bookStore/src/main/webapp/productImg";
Product product1=productService.findProductById(product.getId());
File file1=new File(path,file.getOriginalFilename());
if(file1.exists()){
file1.delete();
}
String fileName = System.currentTimeMillis() + "-" + file.getOriginalFilename();
product.setImgurl("/productImg/"+fileName);
System.out.println(fileName);
file.transferTo(new File(path,fileName));
}
adminService.editProduct(product);
return "/admin/listProduct.do";
}
原文：https://www.cnblogs.com/liuna369-4369/p/10930731.html