基于JSP下的文件上传下载

1.导入所依赖的架包

2.在web.xml下面配置DispatcherServlet，中文乱码过滤器

3.配置spring-mvc.xml

		
		
		
		
		
		
		
		
		
		
		
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            UTF-8
        
	

4.编写一个简单的login.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>







    
用户注册
    

        

            

                
用户名:
                

            
            

                
请上传头像:
                

            
            

                

            
        
    

5.创建一个user实体类，用来接收前端的文件描述和图片

package com.zhiyou100.entity;

import java.io.Serializable;

import org.springframework.web.multipart.MultipartFile;

public class User implements Serializable{
	private String ename;
	private MultipartFile image;
	public String getEname() {
		return ename;
	}
	public void setEname(String ename) {
		this.ename = ename;
	}
	public MultipartFile getImage() {
		return image;
	}
	public void setImage(MultipartFile image) {
		this.image = image;
	}
	
}

6.需要对请求进行处理

UserUploadController.java

import java.io.File;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import com.zhiyou100.entity.User;

@Controller
public class UserUploadController {
	@RequestMapping("/uploadUser.do")
	public String uploadUser(HttpServletRequest request,
			Model model,User user) throws Exception {
		//如果文件不为空，写入上传路径
		if(!user.getImage().isEmpty()) {
			//上传文件路径
			//String path = "最好写到你的工程路径下面，在webapp下面创建一个images文件夹";
			String path = request.getServletContext().getRealPath("/images/");
			//上传文件名
			String filename = user.getImage().getOriginalFilename();
            //保存用于回显图片
			request.setAttribute("image", filename);
			File filepath = new File(path, filename);
			//判断路径是否存在，不存在就创建一个
			if(!filepath.getParentFile().exists()) {
				filepath.getParentFile().mkdirs();
			}
			//将上传文件保存到一个文档目录里
			user.getImage().transferTo(new File(path + File.separator+ filename));
			 //将用户添加到model
            model.addAttribute("user", user);
			return "userInfo";
		}else {
			return "error";
		}
		
		
	}
	
}

7.创建回显页面userInfo.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>







文件下载

   ${requestScope.user.image.originalFilename }

8.对下载请求做出响应

import java.io.File;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.io.FileUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
@Controller
public class DownController {
	@RequestMapping(value="/download.do")
    public ResponseEntity download(HttpServletRequest request,
            @RequestParam("filename") String filename,
            Model model)throws Exception {
       //下载文件路径
       String path = request.getServletContext().getRealPath("/images/");
       File file = new File(path + File.separator + filename);
       HttpHeaders headers = new HttpHeaders();  
       //下载显示的文件名，解决中文名称乱码问题  
       String downloadFielName = new String(filename.getBytes("UTF-8"),"iso-8859-1");
       //通知浏览器以attachment（下载方式）打开图片
       headers.setContentDispositionFormData("attachment", downloadFielName); 
       //application/octetam ： 二进制流数据（最常见的文件下载）。
       headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
       return new ResponseEntity(FileUtils.readFileToByteArray(file),    
               headers, HttpStatus.CREATED);  
 
    }
}

9.效果