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

2019-11-26 13:42:46

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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：

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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