java组件commons-fileupload实现文件上传、下载、在线打开

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：

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

<%@ 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

<%@ 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>

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