springmvc和servlet下的檔案上傳和下載（存檔案目錄和存資料庫Blob兩種方式）
阿新 • • 發佈：2019-01-29
專案中涉及了檔案的上傳和下載，以前在struts2下做過，今天又用springmvc做了一遍，發現springmvc封裝的特別好，基本不用幾行程式碼就完成了，下面把程式碼貼出來：
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: "宋體"; font-size: 14px } </style> <body> <p align="center">檔案上傳下載</p> <form id="form1" name="form1" method="post" action="fileUpload" enctype="multipart/form-data"> <table border="0" align="center"> <tr> <td>上傳檔案：</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="根據Id下載檔案" 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:儲存檔案目錄 try { String path = request.getSession().getServletContext().getRealPath("/");// 檔案儲存目錄，也可自定為絕對路徑 String fileName = file.getOriginalFilename();// getOriginalFilename和getName是不一樣的哦 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:儲存入庫 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(對應的資料庫為db2，儲存blob型別)
<?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"> <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">上傳檔案</a> ${requestScope['upload.message'] }
</body>
</html>以上為springmvc下上傳檔案的Demo，其中很關鍵的一步是，spring的配置檔案中要加入檔案上傳的支援：
<!-- 支援上傳檔案 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>檔案的儲存做了兩種方式，一種是直接存伺服器的檔案目錄；另一種是把檔案流存入資料庫blob欄位內（專案的特需要求）
下面是檔案下載的程式碼：
@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();
// 以流的形式下載檔案
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下檔案上傳下載很簡單明瞭吧？不必像servlet下那麼多的程式碼。