springmvc和servlet下的文件上传和下载（存文件目录和存数据库Blob两种方式）

来源：互联网发布：java短信接口开发demo 编辑：程序博客网时间：2024/05/29 08:22

项目中涉及了文件的上传和下载，以前在struts2下做过，今天又用springmvc做了一遍，发现springmvc封装的特别好，基本不用几行代码就完成了，下面把代码贴出来：

FileUpAndDown.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"%><html><head><title>using commons Upload to upload file</title></head><script type="text/javascript">function downFile(){var fileId = document.getElementById("fileId").value;location.href="fileDownload?fileId=" + fileId;}</script><style>* {font-family: "宋体";font-size: 14px}</style><body><p align="center">文件上传下载</p><form id="form1" name="form1" method="post" action="fileUpload" enctype="multipart/form-data"><table border="0" align="center"><tr><td>上传文件：</td><td><input name="file" type="file" size="20"></td></tr><tr><td></td><td><input type="submit" value="提交"> <input type="reset" name="reset" value="重置"></td></tr></table></form><div align="center"><input type="text" id="fileId"><input type="button" value="根据Id下载文件" onclick="javascript:downFile()"></div></body></html>

FileUpAndDownController.java

@RequestMapping(value = "/fileUpload")public String upload(@RequestParam(value = "file", required = false) MultipartFile file,HttpServletRequest request, ModelMap model) throws IOException {/*// 方式一:保存文件目录try {String path = request.getSession().getServletContext().getRealPath("/");// 文件保存目录，也可自定为绝对路径String fileName = file.getOriginalFilename();// getOriginalFilename和getName是不一样的哦System.out.println(path);File targetFile = new File(path, fileName);if (!targetFile.exists()) {targetFile.mkdirs();}file.transferTo(targetFile);model.addAttribute("upload.message", request.getContextPath() + "/upload/" + fileName);} catch (Exception e) {e.printStackTrace();} */// 方式二:保存入库Map<String, Object> insertMap = new HashMap<String, Object>();insertMap.put("byt", file.getBytes());insertMap.put("fileName", file.getOriginalFilename());int flag = fileUpAndDownMapper.saveFileInfo(insertMap);if(flag > 0)model.addAttribute("upload.message", "success");elsemodel.addAttribute("upload.message", "failure");return "/core/param/businessparam/uploadResult";}

FileUpAndDownMapper.xml(对应的数据库为db2，保存blob类型)

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="com.xx.persistence.FileUpAndDownMapper"><resultMap id="fileBean" type="com.xx.web.FileUpAndDown"><id column="ID" property="id" jdbcType="INTEGER" /><result column="FILENAME" property="fileName" jdbcType="VARCHAR" />    <result column="TESTA" property="testa" javaType="byte[]" jdbcType="BLOB" typeHandler="org.apache.ibatis.type.BlobTypeHandler" />    <result column="FILESTREAM" property="fileStream" javaType="byte[]" jdbcType="BLOB" typeHandler="org.apache.ibatis.type.BlobTypeHandler" /></resultMap>  <insert id="saveFileInfo" parameterType="java.util.HashMap">INSERT INTO BLOBTEST(FILENAME, FILESTREAM)VALUES(#{fileName}, #{byt, javaType=byte[], jdbcType=BLOB, typeHandler=org.apache.ibatis.type.BlobTypeHandler})</insert>    <select id="getFileByPk" resultMap="fileBean" parameterType="int">      SELECT * FROM BLOBTEST WHERE ID=${value}     </select></mapper>

uploadResult.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>uploadResult</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"></head><body><a href="fileManagePage">上传文件</a> ${requestScope['upload.message'] }</body></html>

以上为springmvc下上传文件的Demo，其中很关键的一步是，spring的配置文件中要加入文件上传的支持：

<!-- 支持上传文件 --><bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

文件的保存做了两种方式，一种是直接存服务器的文件目录；另一种是把文件流存入数据库blob字段内（项目的特需要求）

下面是文件下载的代码：

@ResponseBody@RequestMapping(value = "/fileDownload")public void fileDownload(HttpServletRequest request,HttpServletResponse response) throws IOException {String fileId = request.getParameter("fileId");FileUpAndDown file = fileUpAndDownMapper.getFileByPk(Integer.parseInt(fileId));byte[] fileStream = file.getFileStream();String fileName = file.getFileName();// 以流的形式下载文件response.setContentType("application/octet-stream");response.setHeader("Content-Disposition", "attachment; filename=\"" + new String(fileName.getBytes("gb2312"), "ISO8859-1" ) + "\"");OutputStream toClient = new BufferedOutputStream(response.getOutputStream());toClient.write(fileStream);toClient.flush();toClient.close();}

springmvc下文件上传下载很简单明了吧？不必像servlet下那么多的代码。

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