commons-fileupload-1.2.1實作檔案上傳

在java裡實作檔案上傳的元件好多，如jspSmartUpload、commons-fileupload，但是jspSmartUpload差不多淘汰了。

在網上找了下 apache的commons-fileupload相關的使用，調通了程式，放在這裡以後好直接使用。。

用到的jar包：（到www.apache.org下載下傳即可）

commons-fileupload-1.2.1.jar

commons-io-1.4.jar

網上還有更詳細的用法：

http://www.cnblogs.com/yyw84/archive/2007/06/27/797652.html

由于代碼太多，如果大家有興趣，可以自己去參考參考。

這是我自己機器上通過的簡單的代碼，放在下面：

web.xml<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5" 

xmlns="http://java.sun.com/xml/ns/javaee" 

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

<servlet>

<servlet-name>FileUpload</servlet-name>

<servlet-class>FileUpload.FileUploadServlet</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>FileUpload</servlet-name>

<url-pattern>/servlet/FileUploadServlet</url-pattern>

</servlet-mapping> 

<welcome-file-list>

<welcome-file>fileUpload.jsp</welcome-file>

</welcome-file-list>

</web-app>

FileUpload.javapackage FileUpload;

import java.io.File;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Iterator;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;

import org.apache.commons.fileupload.FileUploadException;

import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class FileUploadServlet extends HttpServlet {

public FileUploadServlet() {

super();

}

public void destroy() {

super.destroy(); // Just puts "destroy" string in log

// Put your code here

}

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doPost(request, response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

final String appRealPath = this.getServletContext().getRealPath("/"); //擷取web app的實體路徑

final long MAX_SIZE = 3 * 1024 * 1024;// 設定上傳檔案最大為 3M

final String[] allowedExt = new String[] { "jpg", "jpeg", "gif", "txt",

"doc", "docx", "mp3", "wma", "m4a" }; // 允許上傳的檔案格式的清單

response.setContentType("text/html");

response.setCharacterEncoding("UTF-8"); // 設定字元編碼為UTF-8, 這樣支援漢字顯示

// 執行個體化一個硬碟檔案工廠,用來配置上傳元件ServletFileUpload

DiskFileItemFactory dfif = new DiskFileItemFactory();

dfif.setSizeThreshold(4096);// 設定上傳檔案時用于臨時存放檔案的記憶體大小,這裡是4K.多于的部分将臨時存在硬碟

dfif.setRepository(new File(appRealPath + "ImagesUploadTemp\\"));

// 設定存放臨時檔案的目錄,web根目錄下的ImagesUploadTemp目錄

// 用以上工廠執行個體化上傳元件

ServletFileUpload sfu = new ServletFileUpload(dfif);

sfu.setSizeMax(MAX_SIZE);// 設定最大上傳尺寸

PrintWriter out = response.getWriter();

// 從request得到 所有 上傳域的清單

List fileList = null;

try {

fileList = sfu.parseRequest(request);

} catch (FileUploadException e) {// 處理檔案尺寸過大異常

if (e instanceof SizeLimitExceededException) {

out.println("檔案尺寸超過規定大小:" + MAX_SIZE + "位元組<p />");

out.println("<a href=\" " + request.getContextPath() + "/fileUpload.jsp" + " \" target=\"_top\">傳回</a>");

return;

}

e.printStackTrace();

}

// 沒有檔案上傳

if (fileList == null || fileList.size() == 0) {

out.println("請選擇上傳檔案<p />");

out.println("<a href=\" " + request.getContextPath() + "/fileUpload.jsp" + " \" target=\"_top\">傳回</a>");

return;

}

// 得到所有上傳的檔案

Iterator fileItr = fileList.iterator();

// 循環處理所有檔案

while (fileItr.hasNext()) {

FileItem fileItem = null;

String path = null;

long size = 0;

// 得到目前檔案

fileItem = (FileItem) fileItr.next();

// 忽略簡單form字段而不是上傳域的檔案域(<input type="text" />等)

if (fileItem == null || fileItem.isFormField()) {

continue;

}

// 得到檔案的完整路徑

path = fileItem.getName();

// 得到檔案的大小

size = fileItem.getSize();

if ("".equals(path) || size == 0) {

out.println("請選擇上傳檔案<p />");

out.println("<a href=\" " + request.getContextPath() + "/fileUpload.jsp" + " \" target=\"_top\">傳回</a>");

return;

}

// 得到去除路徑的檔案名

String t_name = path.substring(path.lastIndexOf("\\") + 1);

// 得到檔案的擴充名(無擴充名時将得到全名)

String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1);

// 拒絕接受規定檔案格式之外的檔案類型

int allowFlag = 0;

int allowedExtCount = allowedExt.length;

for (; allowFlag < allowedExtCount; allowFlag++) {

if (allowedExt[allowFlag].equals(t_ext))

break;

}

if (allowFlag == allowedExtCount) {

out.println("請上傳以下類型的檔案<p />");

for (allowFlag = 0; allowFlag < allowedExtCount; allowFlag++)

out.println("*." + allowedExt[allowFlag]

+ "&nbsp;&nbsp;&nbsp;");

out

.println("<a href=\" " + request.getContextPath() + "/fileUpload.jsp" + " \" target=\"_top\">傳回</a>");

return;

}

long now = System.currentTimeMillis();

// 根據系統時間生成上傳後儲存的檔案名

String prefix = String.valueOf(now);

// 儲存的最終檔案完整路徑,儲存在web根目錄下的ImagesUploaded目錄下

String u_name = appRealPath + "ImagesUploaded\\"

+ prefix + "." + t_ext;

try {

// 儲存檔案

fileItem.write(new File(u_name));

out.println("檔案上傳成功. 已儲存為: " + prefix + "." + t_ext

+ " &nbsp;&nbsp;檔案大小: " + size + "位元組<p />");

out.println("<a href=\" " + request.getContextPath() + "/fileUpload.jsp" + " \" target=\"_top\">繼續上傳</a>");

} catch (Exception e) {

e.printStackTrace();

}

}

}

public void init() throws ServletException {

// Put your code here

}

}

fileUpload.jsp<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head> 

<title>My JSP 'fileUpload.jsp' starting page</title>

</head>

<body>

<form action="<%= request.getContextPath() %>/servlet/FileUploadServlet" method="post" enctype="multipart/form-data" >

<input type="file" name="fileUpload" />

<input type="submit" value="upload" />

</form>

</body>

</html>