文章目录
- 前言
- 一、准备
- 1. 打开开关(web.xml)
- 2. 解析器(spring-mvc.xml)
- 二、上传
- 1. 前端
- 2. 后端
- 3. 结果
- 三、下载
- 1.前端
- 2.后端
- 3. 结果
- 总结
前言
请注意，从Spring Framework 6.0及其新的Servlet 5.0+基线开始，基于Apache Commons FileUpload的过时的CommonsMultipartResolver不再可用。
本章节我们基于官方文档来进行文件的上传和下载。
一、准备
1. 打开开关(web.xml)
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="https://jakarta.ee/xml/ns/jakartaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"
version="6.0">
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
<multipart-config/>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
2. 解析器(spring-mvc.xml)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="org.example.springmvc"></context:component-scan>
<!-- <mvc:annotation-driven/>-->
<!--静态资源配置-->
<mvc:resources mapping="/**" location="/resources"></mvc:resources>
<!--视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp"/>
</bean>
<bean id="multipartResolver" class="org.springframework.web.multipart.support.StandardServletMultipartResolver"></bean>
</beans>
二、上传
1. 前端
<%--
Created by IntelliJ IDEA.
User: 张军国001
Date: 2024/5/3
Time: 10:32
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>文件上传和下载</title>
</head>
<body>
<h1><%= "文件上传演示" %></h1>
<br/>
<form action="${pageContext.request.contextPath}/file/upload" method="post" enctype="multipart/form-data">
<span>文件:</span><input type="file" name="file">
<button type="submit">上传</button>
</form>
</body>
</html>
2. 后端
package org.example.springmvc.params.controller;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestPart;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* Create by zjg on 2024/5/3
*/
@RequestMapping("/file/")
@RestController
public class FileController {
String path="WEB-INF/nas";
@RequestMapping("upload")
public void upload(@RequestPart MultipartFile file, HttpServletRequest request,HttpServletResponse response) throws IOException {
String filename = file.getOriginalFilename();
System.out.println(filename);
String realPath = request.getServletContext().getRealPath(path);
File dir = new File(realPath);
if(!dir.exists()){
dir.mkdirs();
}
file.transferTo(new File(realPath+File.separator+filename));
System.out.println(String.format("[%s]上传成功",filename));
response.setStatus(200);
}
}
3. 结果
[springmvc.png]上传成功
三、下载
1.前端
<%--
Created by IntelliJ IDEA.
User: 张军国001
Date: 2024/5/3
Time: 10:32
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>文件上传和下载</title>
</head>
<body>
<h1><%= "文件下载演示" %></h1>
<form action="${pageContext.request.contextPath}/file/download">
<span>文件:</span><input type="text" name="file" id="file">
<button type="submit">下载</button>
</form>
</body>
</html>
2.后端
package org.example.springmvc.params.controller;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestPart;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* Create by zjg on 2024/5/3
*/
@RequestMapping("/file/")
@RestController
public class FileController {
String path="WEB-INF/nas";
@RequestMapping("download")
public void download(String file,HttpServletRequest request,HttpServletResponse response) throws IOException {
String realPath = request.getServletContext().getRealPath(path);
String filename=realPath+File.separator+ file;
File file1 = new File(filename);
if(!file1.exists()){
// 如果文件不存在，则返回404错误
response.sendError(HttpServletResponse.SC_NOT_FOUND);
System.out.println(String.format("文件[%s]不存在",file));
return;
}
downloadFile(file1,response);
System.out.println(String.format("[%s]下载完成",file));
response.setStatus(200);
}
public void downloadFile(File file,HttpServletResponse response) throws IOException {
// 设置响应头
// 设置响应的内容类型为二进制流，这样浏览器就知道如何下载文件而不是尝试显示它
response.setContentType("application/octet-stream");
// 设置响应头中的Content-Disposition，它告诉浏览器这是一个需要下载的文件，以及下载后文件的默认名称
// attachment表示需要下载，filename表示下载后的默认文件名
String headerValue = "attachment; filename=\"" + file.getName() + "\"";
response.setHeader("Content-Disposition", headerValue);
// 设置响应头中的Content-Length，它告诉浏览器文件的大小
response.setContentLength((int) file.length());
// 写入文件内容到输出流
InputStream inputStream = new FileInputStream(file);
OutputStream outputStream = response.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
// 关闭流
inputStream.close();
outputStream.close();
}
}
3. 结果
文件[spring]不存在
[springmvc.png]下载完成
总结
回到顶部
官方文档
