SpringMVC:上传与下载

<bean id="multipartResolver"
		class="org.springframework.web.multipart.commons.CommonsMultipartResolver" p:defaultEncoding="utf-8"/>		

2 WEB-INF/lib下必加入:commons-fileupload.jar与commons-io-1.4.jar二个文件
3 表单属性为: enctype="multipart/form-data"
工程项目图片如下:

具体代码如下:
FileUploadBean.java

public class FileUploadBean {	
	private byte[] file;

	public void setFile(byte[] file) {
		this.file = file;
	}

	public byte[] getFile() {
		return file;
	}
}

package net.liuzd.web;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.BindException;
import java.util.ArrayList;

import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartFile;
import org.springframework.web.servlet.ModelAndView;

/**
 * Title: Description: Copyright: Copyright (c) 2011
 * Company:http://liuzidong.iteye.com/ Makedate:2011-5-27 下午01:52:17
 * 
 * @author liuzidong
 * @version 1.0
 * @since 1.0
 * 
 */
@Controller
public class FileUploadController {

	@RequestMapping(value = "/upload", method = RequestMethod.POST)
	public ModelAndView onSubmit(HttpServletRequest request,
			HttpServletResponse response, BindException errors)
			throws Exception {

		MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
		CommonsMultipartFile file = (CommonsMultipartFile) multipartRequest
				.getFile("file");

		String name = multipartRequest.getParameter("name");
		System.out.println("name: " + name);
		// 获得文件名：
		String realFileName = file.getOriginalFilename();
		System.out.println("获得文件名：" + realFileName);
		// 获取路径
		String ctxPath = request.getSession().getServletContext().getRealPath(
				"/")
				+ "images/";
		// 创建文件
		File dirPath = new File(ctxPath);
		if (!dirPath.exists()) {
			dirPath.mkdir();
		}
		File uploadFile = new File(ctxPath + realFileName);
		FileCopyUtils.copy(file.getBytes(), uploadFile);
		request.setAttribute("files", loadFiles(request));
		return new ModelAndView("success");
	}

	@RequestMapping(value = "/upload2", method = RequestMethod.POST)
	public ModelAndView onSubmit2(HttpServletRequest request,
			HttpServletResponse response, BindException errors)
			throws Exception {

		// 转型为MultipartHttpRequest
		MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
		// 根据前台的name名称得到上传的文件
		MultipartFile file = multipartRequest.getFile("file");
		// 获得文件名：
		String realFileName = file.getOriginalFilename();
		// 获取路径
		String ctxPath = request.getSession().getServletContext().getRealPath(
				"/")
				+ "\\" + "images\\";
		// 创建文件
		File dirPath = new File(ctxPath);
		if (!dirPath.exists()) {
			dirPath.mkdir();
		}
		File uploadFile = new File(ctxPath + realFileName);
		FileCopyUtils.copy(file.getBytes(), uploadFile);
		request.setAttribute("files", loadFiles(request));
		return new ModelAndView("success");
	}

	@RequestMapping(value = "/upload3", method = RequestMethod.POST)
	public String upload(@RequestParam("file")
	MultipartFile image, HttpServletRequest request) throws IOException {

		String ctxPath = request.getSession().getServletContext().getRealPath(
				"/")
				+ "\\" + "images\\";
		System.out.println("路径：" + ctxPath);
		File file = new File(ctxPath + "/" + image.getOriginalFilename());
		// FileCopyUtils.copy(image.getBytes(),new
		// File(ctxPath+"/"+image.getOriginalFilename()));
		try {
			image.transferTo(file); // 保存上传的文件
		} catch (IllegalStateException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		request.setAttribute("files", loadFiles(request));
		return "success";
	}

	// 多文件上传
	@RequestMapping(value = "/upload4", method = RequestMethod.POST)
	public ModelAndView fileUpload(HttpServletRequest request,
			HttpServletResponse response, BindException errors)
			throws Exception {

		MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
		Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
		String ctxPath = request.getSession().getServletContext().getRealPath(
				"/")
				+ "\\" + "images\\";

		File file = new File(ctxPath);
		if (!file.exists()) {
			file.mkdir();
		}
		String fileName = null;
		for (Map.Entry<String, MultipartFile> entity : fileMap.entrySet()) {
			// 上传文件名
			// System.out.println("key: " + entity.getKey());
			MultipartFile mf = entity.getValue();
			fileName = mf.getOriginalFilename();
			File uploadFile = new File(ctxPath + fileName);
			FileCopyUtils.copy(mf.getBytes(), uploadFile);
		}
		request.setAttribute("files", loadFiles(request));
		return new ModelAndView("success");
	}

	// @ModelAttribute("files")//此属性用于初始类时调用,但上传文件后不能时时反应上传文件个数,不适合动态数据
	public List<String> loadFiles(HttpServletRequest request) {
		List<String> files = new ArrayList<String>();
		String ctxPath = request.getSession().getServletContext().getRealPath(
				"/")
				+ "\\" + "images\\";
		File file = new File(ctxPath);
		if (file.exists()) {
			File[] fs = file.listFiles();
			String fname = null;
			for (File f : fs) {
				fname = f.getName();
				if (f.isFile()) {
					files.add(fname);
				}
			}
		}
		return files;
	}

	@RequestMapping("/download/{fileName}")
	public ModelAndView download(@PathVariable("fileName")
	String fileName, HttpServletRequest request, HttpServletResponse response)
			throws Exception {

		response.setContentType("text/html;charset=utf-8");
		request.setCharacterEncoding("UTF-8");
		java.io.BufferedInputStream bis = null;
		java.io.BufferedOutputStream bos = null;

		String ctxPath = request.getSession().getServletContext().getRealPath(
				"/")
				+ "\\" + "images\\";
		String downLoadPath = ctxPath + fileName;
		System.out.println(downLoadPath);
		try {
			long fileLength = new File(downLoadPath).length();
			response.setContentType("application/x-msdownload;");
			response.setHeader("Content-disposition", "attachment; filename="
					+ new String(fileName.getBytes("utf-8"), "ISO8859-1"));
			response.setHeader("Content-Length", String.valueOf(fileLength));
			bis = new BufferedInputStream(new FileInputStream(downLoadPath));
			bos = new BufferedOutputStream(response.getOutputStream());
			byte[] buff = new byte[2048];
			int bytesRead;
			while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
				bos.write(buff, 0, bytesRead);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (bis != null)
				bis.close();
			if (bos != null)
				bos.close();
		}
		return null;
	}
}

spring.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:p="http://www.springframework.org/schema/p"
	xmlns:context="http://www.springframework.org/schema/context"	
	xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">
	<!-- 
		自动搜索@Controller标注的类
		用于指明系统从哪个路径下寻找controller，然后提前初始化这些对象。
	-->
	<context:component-scan base-package="net.liuzd.web" />

	<!--  ③：对模型视图名称的解析，即在模型视图名称添加前后缀 -->
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver"
		p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" />

   
	<bean id="multipartResolver"
		class="org.springframework.web.multipart.commons.CommonsMultipartResolver" p:defaultEncoding="utf-8">
		<property name="maxUploadSize">
			<value>104857600</value>
		</property>
		<property name="maxInMemorySize">
			<value>4096</value>
		</property>
	</bean>
</beans>

success.jsp

<%@ taglib  prefix="c" uri="/WEB-INF/c.tld"%>
<h1>Upload Successful</h1>
	<c:forEach var="month" items="${files}">
    	<li><a href="${pageContext.request.contextPath}/download/${month}.do">${month}</a></li>
	</c:forEach>
  <hr><br>
  <a href="${pageContext.request.contextPath}/index.jsp">返回</a>

web.xml