springmvc和servlet在上传和下载文件（保持文件夹和存储数据库Blob两种方式）(转载)
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="依据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:保存文件文件夹 try { String path = request.getSession().getServletContext().getRealPath("/");// 文件保存 文件夹，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"); else model.addAttribute("upload.message", "failure"); return "/core/param/businessparam/uploadResult"; }
FileUpAndDownMapper. xml(相应的数据库为db2，保存blob类型)<? xml version="1.0" encoding="UTF-8"?
> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "https://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="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，当中非常关键的一步是。spring的配置文件里要增加文件上传的支持：<!-- 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 server的文件文件夹；还有一种是把文件流存入 数据库blob字段内（项目的特须要求）
以下是文件下载的代码：
@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下文件上传下载非常easy明对？不喜欢 servlet在这么多的代码。