JAVA 框架-Springmvc-文件上传与下载

需要的包：spring的21个包，commons-fileupload/io/logging的三个包，标准标签库2个包

异常处理：如果报BeanCreationException: Lookup method resolution failed 可能是缺少必须的包；

spring-servlet.xml配置：

<?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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
		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-4.3.xsd">
<context:component-scan base-package="com.hanqi.controller"></context:component-scan><!--注解扫描器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"><!-- 视图解析器 -->
	<property name="prefix" value="/WEB-INF/page/"></property>
	<property name="suffix" value=".jsp"></property>
</bean>
<!--配置spring里带的文件上传类-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
	<!-- 可以上传的文件的总大小, 单位(b), 1KB=1024b -->
	<property name="maxUploadSize" value="1000000000"></property>
	<!-- 可以上传的单个文件的大小, 单位(b) -->
	<property name="maxUploadSizePerFile" value="100000000"></property>
	<!-- 默认的字符集 -->
	<property name="defaultEncoding" value="UTF-8"></property>
</bean>
</beans>

文件上传页：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>上传文件页面</title>
</head>
<body>
<form action="file/upload.do" method="post" enctype="multipart/form-data">
	<input type="file" name="file" ><br>
	<input type="submit" value="提交">
</form><br>
<a href="${pageContext.request.contextPath }/download.do">查看上传文件</a>
</body>
</html>

文件下载页：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>下载文件页面</title>
</head>
<body>
<a href="index.jsp">上传文件</a><br>
<!--第一种下载方式，直接加上download属性即可，仅支持火狐和谷歌浏览器-->
<c:forEach items="${fileList}" var="f">
	<a href="files/${f}" download>${f }</a><br>
</c:forEach>
<!--第二种下载方式,将文件名作为请求参数传入后台-->
<c:forEach items="${fileList}" var="f">
	<a href="file/download.do?filename=${f }">${f }</a><br>
</c:forEach>
</body>
</html>

文件控制器类：

package com.hanqi.controller;

import java.io.File;
import java.io.IOException;
import java.util.Date;

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.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;

@Controller
@RequestMapping("/file")
public class FileController {
	@RequestMapping("/upload")
	public String upload(MultipartFile file,HttpServletRequest request) {
		System.out.println(file.getName());// input控件中name属性的值
		System.out.println(file.getSize()); // 文件大小
		System.out.println(file.getOriginalFilename());// 文件名
		//在WebContent下新建一个files文件夹，并获取其物理路径
		String path = request.getServletContext().getRealPath("/files");
		//新建一个空的文件，File.separator相当于"/",同时加上一个时间戳，用于区分相同名字的文件
		File orgFile = new File(path + File.separator + new Date().getTime()+"-" + file.getOriginalFilename());
		try {
			//将接收到的文件放到空的文件中
			//该文件实际存放在D:eclipse workspace.metadata.pluginsorg.eclipse.wst.server.core
			//	mp0wtpwebappsspring-filefiles
			file.transferTo(orgFile);
		} catch (IllegalStateException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return "success";
	}
	@RequestMapping("/download")
	public ResponseEntity<byte[]> testDownLoad(
			HttpServletRequest request,
			String filename) throws Exception {
		// String orgFilename = new String(filename.getBytes("iso-8859-1"), "utf-8");
		String path = 
				request.getServletContext().getRealPath("/files");
		// File orgFile = new File(path + "/" + orgFilename);
		File orgFile = new File(path + "/" + filename);
		// 设置请求头信息
		HttpHeaders hh = new HttpHeaders();
		// 告诉前台, 以(attachement, 就是下载)的方式打开文件
		hh.setContentDispositionFormData("attachment", new String(filename.getBytes("utf-8"), "iso-8859-1"));
		// 以二进制流的形式传输文件, 这是最常见的下载方式
		hh.setContentType(MediaType.APPLICATION_OCTET_STREAM);
		return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(orgFile), hh, 
				HttpStatus.CREATED);
	}
}

页面跳转控制类：

package com.hanqi.controller;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

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

@Controller
public class FormController {
	@RequestMapping("/{path}")
	public String toPage(@PathVariable("path")String page,Model model,HttpServletRequest request) {
		if("download".equals(page)) {
			String path = request.getServletContext().getRealPath("/files");
			File orgFiles = new File(path);
			File[] files = orgFiles.listFiles();
			List fileList = new ArrayList();
			for(File f:files) {
				fileList.add(f.getName());
			}
			model.addAttribute("fileList", fileList);
		}
		return page;
	}
}