Spring MVC 文件上传下载

本文基于Spring MVC 注解，让Spring跑起来。

(1) 导入jar包：ant.jar、commons-fileupload.jar、connom-io.jar。

(2) 在src/context/dispatcher.xml中添加

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

注意，需要在头部添加内容，添加后如下所示：

    <beans default-lazy-init="true"
        xmlns="http://www.springframework.org/schema/beans"
        xmlns:p="http://www.springframework.org/schema/p"
         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-3.0.xsd
           http://www.springframework.org/schema/mvc
           http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-3.0.xsd">  

(3) 添加工具类FileOperateUtil.java

    /**
     *
     * @author geloin
     * @date 2012-5-5 下午12:05:57
     */
    package com.geloin.spring.util;  

    import java.io.BufferedInputStream;
    import java.io.BufferedOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.text.SimpleDateFormat;
    import java.util.ArrayList;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.List;
    import java.util.Map;  

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

    import org.apache.tools.zip.ZipEntry;
    import org.apache.tools.zip.ZipOutputStream;
    import org.springframework.util.FileCopyUtils;
    import org.springframework.web.multipart.MultipartFile;
    import org.springframework.web.multipart.MultipartHttpServletRequest;  

    /**
     *
     * @author geloin
     * @date 2012-5-5 下午12:05:57
     */
    public class FileOperateUtil {
        private static final String REALNAME = "realName";
        private static final String STORENAME = "storeName";
        private static final String SIZE = "size";
        private static final String SUFFIX = "suffix";
        private static final String CONTENTTYPE = "contentType";
        private static final String CREATETIME = "createTime";
        private static final String UPLOADDIR = "uploadDir/";  

        /**
         * 将上传的文件进行重命名
         *
         * @author geloin
         * @date 2012-3-29 下午3:39:53
         * @param name
         * @return
         */
        private static String rename(String name) {  

            Long now = Long.parseLong(new SimpleDateFormat("yyyyMMddHHmmss")
                    .format(new Date()));
            Long random = (long) (Math.random() * now);
            String fileName = now + "" + random;  

            if (name.indexOf(".") != -1) {
                fileName += name.substring(name.lastIndexOf("."));
            }  

            return fileName;
        }  

        /**
         * 压缩后的文件名
         *
         * @author geloin
         * @date 2012-3-29 下午6:21:32
         * @param name
         * @return
         */
        private static String zipName(String name) {
            String prefix = "";
            if (name.indexOf(".") != -1) {
                prefix = name.substring(0, name.lastIndexOf("."));
            } else {
                prefix = name;
            }
            return prefix + ".zip";
        }  

        /**
         * 上传文件
         *
         * @author geloin
         * @date 2012-5-5 下午12:25:47
         * @param request
         * @param params
         * @param values
         * @return
         * @throws Exception
         */
        public static List<Map<String, Object>> upload(HttpServletRequest request,
                String[] params, Map<String, Object[]> values) throws Exception {  

            List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();  

            MultipartHttpServletRequest mRequest = (MultipartHttpServletRequest) request;
            Map<String, MultipartFile> fileMap = mRequest.getFileMap();  

            String uploadDir = request.getSession().getServletContext()
                    .getRealPath("/")
                    + FileOperateUtil.UPLOADDIR;
            File file = new File(uploadDir);  

            if (!file.exists()) {
                file.mkdir();
            }  

            String fileName = null;
            int i = 0;
            for (Iterator<Map.Entry<String, MultipartFile>> it = fileMap.entrySet()
                    .iterator(); it.hasNext(); i++) {  

                Map.Entry<String, MultipartFile> entry = it.next();
                MultipartFile mFile = entry.getValue();  

                fileName = mFile.getOriginalFilename();  

                String storeName = rename(fileName);  

                String noZipName = uploadDir + storeName;
                String zipName = zipName(noZipName);  

                // 上传成为压缩文件
                ZipOutputStream outputStream = new ZipOutputStream(
                        new BufferedOutputStream(new FileOutputStream(zipName)));
                outputStream.putNextEntry(new ZipEntry(fileName));
                outputStream.setEncoding("GBK");  

                FileCopyUtils.copy(mFile.getInputStream(), outputStream);  

                Map<String, Object> map = new HashMap<String, Object>();
                // 固定参数值对
                map.put(FileOperateUtil.REALNAME, zipName(fileName));
                map.put(FileOperateUtil.STORENAME, zipName(storeName));
                map.put(FileOperateUtil.SIZE, new File(zipName).length());
                map.put(FileOperateUtil.SUFFIX, "zip");
                map.put(FileOperateUtil.CONTENTTYPE, "application/octet-stream");
                map.put(FileOperateUtil.CREATETIME, new Date());  

                // 自定义参数值对
                for (String param : params) {
                    map.put(param, values.get(param)[i]);
                }  

                result.add(map);
            }
            return result;
        }  

        /**
         * 下载
         *
         * @author geloin
         * @date 2012-5-5 下午12:25:39
         * @param request
         * @param response
         * @param storeName
         * @param contentType
         * @param realName
         * @throws Exception
         */
        public static void download(HttpServletRequest request,
                HttpServletResponse response, String storeName, String contentType,
                String realName) throws Exception {
            response.setContentType("text/html;charset=UTF-8");
            request.setCharacterEncoding("UTF-8");
            BufferedInputStream bis = null;
            BufferedOutputStream bos = null;  

            String ctxPath = request.getSession().getServletContext()
                    .getRealPath("/")
                    + FileOperateUtil.UPLOADDIR;
            String downLoadPath = ctxPath + storeName;  

            long fileLength = new File(downLoadPath).length();  

            response.setContentType(contentType);
            response.setHeader("Content-disposition", "attachment; filename="
                    + new String(realName.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);
            }
            bis.close();
            bos.close();
        }
    }  

可完全使用而不必改变该类，需要注意的是，该类中设定将上传后的文件放置在WebContent/uploadDir下。

(4) 添加FileOperateController.java

    /**
     *
     * @author geloin
     * @date 2012-5-5 上午11:56:35
     */
    package com.geloin.spring.controller;  

    import java.util.HashMap;
    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.web.bind.ServletRequestUtils;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.servlet.ModelAndView;  

    import com.geloin.spring.util.FileOperateUtil;  

    /**
     *
     * @author geloin
     * @date 2012-5-5 上午11:56:35
     */
    @Controller
    @RequestMapping(value = "background/fileOperate")
    public class FileOperateController {
        /**
         * 到上传文件的位置
         *
         * @author geloin
         * @date 2012-3-29 下午4:01:31
         * @return
         */
        @RequestMapping(value = "to_upload")
        public ModelAndView toUpload() {
            return new ModelAndView("background/fileOperate/upload");
        }  

        /**
         * 上传文件
         *
         * @author geloin
         * @date 2012-3-29 下午4:01:41
         * @param request
         * @return
         * @throws Exception
         */
        @RequestMapping(value = "upload")
        public ModelAndView upload(HttpServletRequest request) throws Exception {  

            Map<String, Object> map = new HashMap<String, Object>();  

            // 别名
            String[] alaises = ServletRequestUtils.getStringParameters(request,
                    "alais");  

            String[] params = new String[] { "alais" };
            Map<String, Object[]> values = new HashMap<String, Object[]>();
            values.put("alais", alaises);  

            List<Map<String, Object>> result = FileOperateUtil.upload(request,
                    params, values);  

            map.put("result", result);  

            return new ModelAndView("background/fileOperate/list", map);
        }  

        /**
         * 下载
         *
         * @author geloin
         * @date 2012-3-29 下午5:24:14
         * @param attachment
         * @param request
         * @param response
         * @return
         * @throws Exception
         */
        @RequestMapping(value = "download")
        public ModelAndView download(HttpServletRequest request,
                HttpServletResponse response) throws Exception {  

            String storeName = "201205051340364510870879724.zip";
            String realName = "Java设计模式.zip";
            String contentType = "application/octet-stream";  

            FileOperateUtil.download(request, response, storeName, contentType,
                    realName);  

            return null;
        }
    }  

下载方法请自行变更，若使用数据库保存上传文件的信息时，请参考Spring MVC 整合Mybatis实例。
        (5) 添加fileOperate/upload.jsp

    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
    <!DOCTYPE html
    PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Insert title here</title>
    </head>
    <body>
    </body>
    <form enctype="multipart/form-data"
        action="<c:url value="/background/fileOperate/upload.html" />" method="post">
        <input type="file" name="file1" /> <input type="text" name="alais" /><br />
        <input type="file" name="file2" /> <input type="text" name="alais" /><br />
        <input type="file" name="file3" /> <input type="text" name="alais" /><br />
        <input type="submit" value="上传" />
    </form>
    </html>  

确保enctype的值为multipart/form-data；method的值为post。

(6) 添加fileOperate/list.jsp

    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
    <!DOCTYPE html
    PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Insert title here</title>
    </head>
    <body>
        <c:forEach items="${result }" var="item">
            <c:forEach items="${item }" var="m">
                <c:if test="${m.key eq 'realName' }">
                    ${m.value }
                </c:if>
                <br />
            </c:forEach>
        </c:forEach>
    </body>
    </html>  

(7) 通过http://localhost:8080/spring_test/background/fileOperate /to_upload.html访问上传页面，通过http://localhost:8080/spring_test/background /fileOperate/download.html下载文件