文件上传和下载
一、创建SpringMVC项目
略
二、导入支持的包
<!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
三、配置applicationContext.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
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!--自动扫描指定包-->
<context:component-scan base-package="com.aurora.controller"/>
<!--静态资源过滤-->
<mvc:default-servlet-handler/>
<!--注解驱动-->
<mvc:annotation-driven/>
<!--视图解析器：DispatcherServlet给他的ModelAndView-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
<!--前缀-->
<property name="prefix" value="/WEB-INF/jsp/"/>
<!--后缀-->
<property name="suffix" value=".jsp"/>
</bean>
<!--文件上传配置-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="utf-8"/>
<property name="maxUploadSize" value="10485760"/>
<property name="maxInMemorySize" value="40960"/>
</bean>
</beans>
四、前端
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/upload" enctype="multipart/form-data" method="post">
<input type="file" name="file"/>
<input type="submit" value="upload"/>
</form>
</body>
</html>
五、controller层
@RestController
public class FileController {
@RequestMapping("/upload")
public String upload(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
String uploadFileName = file.getOriginalFilename();
//文件名为空返回首页
if ("".equals(uploadFileName)){
return "redirect:/index.jsp";
}
System.out.println("上传文件名："+uploadFileName);
//上传路径保存设置
String path = request.getServletContext().getRealPath("/upload");
File realPath = new File(path);
if (!realPath.exists()){
realPath.mkdir();
}
System.out.println("上传文件保存地址："+realPath);
InputStream is = file.getInputStream();
FileOutputStream os = new FileOutputStream(new File(realPath, uploadFileName));
//读取写出
int len=0;
byte[] buffer = new byte[1024];
while ((len=is.read(buffer))!=-1){
os.write(buffer,0,len);
os.flush();
}
os.close();
is.close();
return "redirect:/index.jsp";
}
//采用file.Transto来保存上传的文件
@RequestMapping("/upload2")
public String upload2(@RequestParam("file") CommonsMultipartFile file,HttpServletRequest request) throws IOException {
//上传路径保存设置
String path = request.getServletContext().getRealPath("/upload");
File realPath = new File(path);
if (!realPath.exists()){
realPath.mkdir();
}
//上传文件地址
System.out.println("上传文件保存地址："+realPath);
//通过CommonsMultipartFile的方法直接写文件
file.transferTo(new File(realPath+"/"+file.getOriginalFilename()));
return "redirect:/index.jsp";
}
}
@RequestMapping(value = "/download")
public String downloads(HttpServletResponse response,HttpServletRequest request)throws Exception{
//要下载图片的地址
String path = request.getServletContext().getRealPath("/upload");
String fileName="1.png";
//1、设置response响应头
response.reset();//清空缓存
response.setCharacterEncoding("UTF-8");
response.setContentType("multipart/form-data");//二进制传输数据
//设置响应头
response.setHeader("Content-Disposition","attachment;fileName="+ URLEncoder.encode(fileName,"UTF-8"));
File file = new File(path, fileName);
//2、读取文件
FileInputStream is = new FileInputStream(file);
//3、写出文件
OutputStream out = response.getOutputStream();
int index=0;
byte[] buffer = new byte[1024];
while ((index=is.read(buffer))!=-1){
out.write(buffer,0,index);
out.flush();
}
out.close();
is.close();
return null;
}