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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