commons-fileupload实现文件上传、下载、在线打开

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最近做了一个文件上传、下载、与在线打开文件的功能，刚开始对文件上传的界面中含有其它表单（例如输入框、密码等）在上传的过程中遇到了许多问题，下面我写了一个同时实现文件上传、下载、在线打开文件的测试程序。

首先请看效果图：

核心代码：

[java]  view plain copy  
 package com.jefry;  
   
 import java.io.File;  
 import java.io.FileInputStream;  
 import java.io.IOException;  
 import java.net.URL;  
 import java.util.ArrayList;  
 import java.util.Iterator;  
 import java.util.List;  
   
 import javax.servlet.ServletException;  
 import javax.servlet.ServletOutputStream;  
 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.disk.DiskFileItemFactory;  
 import org.apache.commons.fileupload.servlet.ServletFileUpload;  
   
 /** 
  * Servlet implementation class FileUpload 
  */  
 public class FileUpload extends HttpServlet {  
     private static final long serialVersionUID = 1L;  
     private static final String fileDir = "F:/";  
     /** 
      * Default constructor. 
      */  
     public FileUpload() {  
           
     }  
   
     protected void doGet(HttpServletRequest request,  
             HttpServletResponse response) throws ServletException, IOException {  
       
         String aFileName = request.getParameter("fileName");   
         String online = request.getParameter("online");  
         FileInputStream in = null;   
         ServletOutputStream out = null;   
         boolean isOnLine = online != null ? true : false ;  
         try {  
           
               
             if(isOnLine){   
                 URL u = new URL("file:///"+fileDir + aFileName);  
                 response.setContentType(u.openConnection().getContentType());  
                 response.setHeader("Content-Disposition", "inline; filename="+aFileName);     
              }  
             else{   
                 response.setContentType("application/x-msdownload");   
                 response.setHeader("Content-Disposition", "attachment; filename=" + aFileName);   
             }  
           
             in = new FileInputStream(fileDir + aFileName);   
             out = response.getOutputStream();  
             out.flush();  
             int aRead = 0;  
             while ((aRead = in.read()) != -1 & in != null) {  
                 out.write(aRead);  
              }  
             out.flush();  
               
         } catch (Throwable e) {  
             e.printStackTrace();  
         } finally {  
             try {  
                 in.close();  
                 out.close();  
             } catch (Throwable e) {  
                 e.printStackTrace();  
             }  
         }  
   
     }  
   
     protected void doPost(HttpServletRequest request,  
             HttpServletResponse response) throws ServletException, IOException {  
         try {  
             DiskFileItemFactory fileFactory = new DiskFileItemFactory();  
             ServletFileUpload fu = new ServletFileUpload(fileFactory);  
             List fileItems = fu.parseRequest(request);  
             Iterator iter = fileItems.iterator();  
             String uploader = null;  
             String date = null;  
             List<String> fileNames = new ArrayList<String>();  
             while (iter.hasNext()) {  
                 FileItem item = (FileItem) iter.next();  
                 if (!item.isFormField()) { // 文件  
                     String oldFileName = item.getName();  
                     String newFileName = null;  
                     int delimiter = oldFileName.lastIndexOf("/");  
                     if (delimiter == -1)  
                         newFileName = oldFileName.substring(delimiter + 1);  
                     else  
                         newFileName = oldFileName;  
                     fileNames.add(newFileName);  
                     item.write(new File(fileDir + newFileName));  
                 } else { // 表单  
                     String fieldName = item.getFieldName();  
                     if ("uploader".equals(fieldName)) {  
                         uploader = item.getString();  
                     } else if ("date".equals(fieldName)) {  
                         date = item.getString();  
                     }  
                 }  
             }  
             request.setAttribute("fileNames",fileNames);  
             request.getRequestDispatcher("download.jsp").forward(request, response);  
         } catch (Exception e) {  
   
         }  
     }  
   
 }  

index.jsp

[html]  view plain copy  
 <%@ page language="java" contentType="text/html; charset=UTF-8"  
     pageEncoding="UTF-8"%>  
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
 <html>  
 <head>  
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
 <title>Insert title here</title>  
 </head>  
 <body>  
  <form action="FileUpload" method="post" enctype="multipart/form-data">  
  <br>  
    文件一：<input type="file" name="file1" /> <br>  
     文件二：<input type="file" name="file2" /> <br>  
         上传者:<input type="text" name="uploader"/> <br>  
              日期:<input type="text" name="date"/> <br>  
             <input type="submit" value="提交"/>  
     
  </form>  
 </body>  
 </html>  

download.jsp

[html]  view plain copy  
 <%@ page language="java" contentType="text/html; charset=UTF-8"  
     pageEncoding="UTF-8"%>  
 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
   
 <%@page import="java.util.List"%><html>  
 <head>  
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
 <title>Insert title here</title>  
 </head>  
 <body>  
    
  <br>  
   --------------直接下载------------  
      <br>  
       <%  
         List<String> fileNames = (List<String> )request.getAttribute("fileNames");   
         for(String fileName : fileNames) {  
       %>  
        
         <form action="FileUpload" method="get">  
             <input type="hidden" name="fileName" value="<%=fileName %>" />  
             <input type="submit" value="下载:<%=fileName %>" />  
         </form>  
      <%  
         }  
      %>  
      <br>  
       --------------直接打开---------  
      <%   
        for(String fileName : fileNames) {  
       %>  
         <form action="FileUpload" method="get">  
             <input type="hidden" name="fileName" value="<%=fileName %>" />  
             <input type="hidden" name="online" value="yes" />  
             <input type="submit" value="打开:<%=fileName %>" />  
         </form>  
      <%  
         }  
      %>  
      </br>  
   
 </body>  
 </html>  