文件上传下载
文件上传下载
创建模块
web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<filter>
<filter-name>CharacterEncodingFilterfilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>UTF-8param-value>
init-param>
<init-param>
<param-name>forceResponseEncodingparam-name>
<param-value>trueparam-value>
init-param>
filter>
<filter-mapping>
<filter-name>CharacterEncodingFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
<filter>
<filter-name>HiddenHttpMethodFilterfilter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilterfilter-class>
filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
<servlet>
<servlet-name>DispatcherServletservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath:springMVC.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>DispatcherServletservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
web-app>
SpringMVC.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<context:component-scan base-package="com.louis">context:component-scan>
<bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
<property name="order" value="1"/>
<property name="characterEncoding" value="UTF-8"/>
<property name="templateEngine">
<bean class="org.thymeleaf.spring5.SpringTemplateEngine">
<property name="templateResolver">
<bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
<property name="prefix" value="/WEB-INF/templates/"/>
<property name="suffix" value=".html"/>
<property name="templateMode" value="HTML5"/>
<property name="characterEncoding" value="UTF-8"/>
bean>
property>
bean>
property>
bean>
beans>
依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0modelVersion>
<parent>
<groupId>com.louisgroupId>
<artifactId>springMVCartifactId>
<version>1.0-SNAPSHOTversion>
parent>
<artifactId>springMVC-07artifactId>
<packaging>warpackaging>
<name>springMVC-07 Maven Webappname>
<url>http://maven.apache.orgurl>
<dependencies>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>4.0.1version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>5.3.1version>
dependency>
<dependency>
<groupId>org.thymeleafgroupId>
<artifactId>thymeleaf-spring5artifactId>
<version>3.0.12.RELEASEversion>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>2.15.2version>
dependency>
<dependency>
<groupId>commons-fileuploadgroupId>
<artifactId>commons-fileuploadartifactId>
<version>1.3.3version>
dependency>
dependencies>
<build>
<finalName>springMVC-07finalName>
build>
project>
文件下载
将文件从服务器端下载到浏览器端，本质是文件复制，使用ResponseEntity可以实现文件下载的功能。
实现步骤
①目标内容
网上下载目标文件(图片)复制到static下的img文件夹中
②创建页面
在templates下创建首页的文件
index.html
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" xmlns:th="http://www.thymeleaf.org">
<title>测试文件上传和下载title>
head>
<body>
<a th:href="@{/testDown}">下载1.jpga>
body>
html>
③配置SpringMVC.xml
由于查看首页只涉及到页面跳转没有业务功能，所以只需要在SpringMVC.xml下进行配置即可。不需要单独的控制器。
<mvc:view-controller path="/" view-name="index">mvc:view-controller>
<mvc:annotation-driven>mvc:annotation-driven>
④FileUpAndDownController
在controller下创建FileUpAndDownController控制器
package com.louis.controller;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import java.io.FileInputStream;
import java.io.IOException;
/**
* @author XRY
* @date 2023年07月04日15:10
*/
@Controller
public class FileUpAndDownController {
@RequestMapping("/testDown")
public ResponseEntity<byte[]> testResponseEntity(HttpSession session) throws IOException {
//获取ServletContext对象
ServletContext servletContext = session.getServletContext();
//获取服务器中文件的真实路径
String realPath = servletContext.getRealPath("/static/img/1.jpg");
//创建输入流
FileInputStream fis = new FileInputStream(realPath);
//创建字节数组
byte[] bytes = new byte[fis.available()];
//将流读到字节数组中
fis.read(bytes);
//创建HttpHeaders对象设置响应头信息,Map---响应头是键值对
MultiValueMap<String, String> httpHeaders = new HttpHeaders();
//设置下载方式以及下载文件的名字，只能修改文件名，其他都是固定写法，设置下载方式
httpHeaders.add("Content-Disposition", "attachment;filename=1.jpg");
//设置响应状态码
HttpStatus statusCode = HttpStatus.OK;
//创建ResponseEntity对象
ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes, httpHeaders, statusCode);
//关闭输入流
fis.close();
return responseEntity;
}
}
⑤测试
文件上传
文件上传要求form表单的请求方式必须为post，并且添加属性enctype=“multipart/form-data”，SpringMVC中上传的文件封装到MultipartFile对象中，通过此对象可以获取文件相关信息。
实现步骤
①补充依赖
<dependency>
<groupId>commons-fileuploadgroupId>
<artifactId>commons-fileuploadartifactId>
<version>1.3.3version>
dependency>
②配置SpringMVC.xml
在SpringMVC.xml配置文件上传解析器
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">bean>
③index.html
<form th:action="@{/testUp}" method="post" enctype="multipart/form-data">
头像:<input type="file" name="photo"><br/>
<input type="submit" value="上传">
form>
④success.html
创建上传成功之后跳转的页面success.html
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" xmlns:th="http://www.thymeleaf.org">
<title>Titletitle>
head>
<body>
上传成功
body>
html>
⑤FileUpAndDownController
@RequestMapping("/testUp")
//将上传的文件进行封装,但上传的文件不能直接转换为MultipartFile对象，需要配置文件上传解析器
//使用session获取服务器路径
public String testUp(MultipartFile photo, HttpSession session) throws IOException {
//上传操作
System.out.println(photo.getName());//photo
System.out.println(photo.getOriginalFilename());//24f2a9d47e3673a094df34c5260a081f.jpeg
String fileName = photo.getOriginalFilename();
ServletContext servletContext = session.getServletContext();
String photoPath = servletContext.getRealPath("photo");//将文件上传到服务器的photo目录下
File file = new File(photoPath);
//判断photoPath所对应路径是否存在
if(!file.exists()){
//不存在，则创建目录
file.mkdir();
}
//File.separator用于设置分隔符，/或\
String finalPath = photoPath + File.separator + fileName;
photo.transferTo(new File(finalPath));
return "success";
}
⑥测试
在target下打开当前项目的目录位置，在其中的photo文件夹中查看结果。
完整controller
package com.louis.controller;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;
/**
* @author XRY
* @date 2023年07月04日15:10
*/
@Controller
public class FileUpAndDownController {
@RequestMapping("/testDown")
public ResponseEntity<byte[]> testResponseEntity(HttpSession session) throws IOException {
//获取ServletContext对象
ServletContext servletContext = session.getServletContext();
//获取服务器中文件的真实路径
String realPath = servletContext.getRealPath("/static/img/1.jpg");
//创建输入流
FileInputStream fis = new FileInputStream(realPath);
//创建字节数组
byte[] bytes = new byte[fis.available()];
//将流读到字节数组中
fis.read(bytes);
//创建HttpHeaders对象设置响应头信息,Map---响应头是键值对
MultiValueMap<String, String> httpHeaders = new HttpHeaders();
//设置下载方式以及下载文件的名字，只能修改文件名，其他都是固定写法，设置下载方式
httpHeaders.add("Content-Disposition", "attachment;filename=1.jpg");
//设置响应状态码
HttpStatus statusCode = HttpStatus.OK;
//创建ResponseEntity对象
ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes, httpHeaders, statusCode);
//关闭输入流
fis.close();
return responseEntity;
}
@RequestMapping("/testUp")
//将上传的文件进行封装,但上传的文件不能直接转换为MultipartFile对象，需要配置文件上传解析器
//使用session获取服务器路径
public String testUp(MultipartFile photo, HttpSession session) throws IOException {
//上传操作
System.out.println(photo.getName());//photo
System.out.println(photo.getOriginalFilename());//picture.jpeg
//获取上传文件的文件名
String fileName = photo.getOriginalFilename();
//解决文件重名问题
//1、获取上传文件的后缀名,获取最后一个点
String suffixName = fileName.substring(fileName.lastIndexOf("."));
//2、将UUID作为文件名
String uuid = UUID.randomUUID().toString().replaceAll("-","");
//3、将UUID和后缀拼接后的结果作为最终文件名
fileName = uuid + suffixName;
//通过ServletContext获取服务器中photo目录的路径
ServletContext servletContext = session.getServletContext();
String photoPath = servletContext.getRealPath("photo");//将文件上传到服务器的photo目录下
File file = new File(photoPath);
//判断photoPath所对应路径是否存在
if(!file.exists()){
//不存在，则创建目录
file.mkdir();
}
//File.separator用于设置分隔符，/或\
String finalPath = photoPath + File.separator + fileName;
photo.transferTo(new File(finalPath));
return "success";
}
}