有关FileUpload组件的使用和调试的经验(转)

在通过使用FileUpload组件上传的过程中，通过自己的调试，总结如下：
1）使用之前的准备，我用的是commons-fileupload-1.1-dev.jar和commons-io-1.1-dev.jar。
   解释一下：尽管有的资料解释是commons-fileupload-1.0-beta.jar和commons-beanutils.jar，通过调试的结果
   显示并不是需要commons-beanutils.jar文件，而是由于在parseRequest(request)的类有关继承于DiskFileItem
类。而他有private  org.apache.commons.io.output.DeferredFileOutputStream dfos。这样的就必须使用到commons-io-1.1-dev.jar。因此需要导入该包。否则就出classNotFound：.DeferredFileOutputStream的错误。

2）由于涉及文件，就涉及到文件系统。然而在java或应用服务器中对于文件系统的访问，就有一定的安全策略。
  需要将下列权限添加到您应用程序服务器的安全策略文件中：
permission java.io.FilePermission "<<ALL FILES>>", "read,write,delete";
具体是添加到..\bea\weblogic81\server\lib\weblogic.policy中的.
否则会可能出如下异常错误：
org.apache.commons.fileupload.FileUploadException:
java.lang.reflect.InvocationTargetException
at
org.apache.commons.fileupload.FileUpload.createItem(FileUpload.java:615)
at
org.apache.commons.fileupload.FileUpload.parseRequest(FileUpload.java:474)
at
org.apache.commons.fileupload.FileUpload.parseRequest(FileUpload.java:355)
....

3）对于不同的服务器，在调试的过程中会出各种不一样的结果。这个与具体的服务器有关。

4）由于FileUpload在不断的更新版本，它的很多方法已经不推荐使用了（这与该组件的不断的改进有关）。通过对最新的帮助文档和网上的资料写了一个标准的程序如下：
fileUpload文件：

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.*;
import java.util.*;
import java.util.regex.*;
import java.io.*;
import org.apache.commons.fileupload.servlet.*;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;

/*
 * 创建日期 2005-4-10
 *
 * TODO 要更改此生成的文件的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */

/**
 * @author gaolong1
 *
 * TODO 要更改此生成的类型注释的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
public class FileUpload extends HttpServlet {

 /**
  * Destruction of the servlet. <br>
  */
 private String uploadPath = "D:\\addnetFile\\"; // 用于存放上传文件的目录
    private File tempPath =new File("D:\\addnetFile\\tmp\\"); // 用于存放临时文件的目录
 public void destroy() {
  super.destroy(); // Just puts "destroy" string in log
  // Put your code here
 }

 /**
  * The doPost method of the servlet. <br>
  *
  * This method is called when a form has its tag value method equals to post.
  *
  * @param request the request send by the client to the server
  * @param response the response send by the server to the client
  * @throws ServletException if an error occurred
  * @throws IOException if an error occurred
  */
  public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException{
   res.setContentType( "text/html; charset=GB2312");
  PrintWriter out=res.getWriter();
  System.out.println(req.getContentLength());
     System.out.println(req.getContentType());
   DiskFileItemFactory factory = new DiskFileItemFactory();
        // maximum size that will be stored in memory
        factory.setSizeThreshold(4096);
        // the location for saving data that is larger than getSizeThreshold()
        factory.setRepository(new File("d:\\File\\addnetFile\\temp"));

        ServletFileUpload upload = new ServletFileUpload(factory);
        // maximum size before a FileUploadException will be thrown
        upload.setSizeMax(1000000);
        try{
        List fileItems = upload.parseRequest(req);
        // assume we know there are two files. The first file is a small
        // text file, the second is unknown and is written to a file on
        // the server
        Iterator iter = fileItems.iterator();

//  正则匹配，过滤路径取文件名
     String regExp=".+\\\\(.+)$";

//  过滤掉的文件类型
  String[] errorType={".exe",".com",".cgi",".asp"};
     Pattern p = Pattern.compile(regExp);
        while (iter.hasNext()) {
         FileItem item = (FileItem)iter.next();
         //忽略其他不是文件域的所有表单信息
         if (!item.isFormField()) {
             String name = item.getName();
             long size = item.getSize();
             if((name==null||name.equals("")) && size==0)
                 continue;
          Matcher m = p.matcher(name);
         boolean result = m.find();
         if (result){
             for (int temp=0;temp<errorType.length;temp++){
             if (m.group(1).endsWith(errorType[temp])){
                   throw new IOException(name+": wrong type");
             }
             }
             try{

//        保存上传的文件到指定的目录

//        在下文中上传文件至数据库时，将对这里改写
                     item.write(new File("d:\\" + m.group(1)));

                   out.print(name+"&nbsp;&nbsp;"+size+"<br>");
                   }
                   catch(Exception e){
                     out.println(e);
                   }

                }
               else
               {
                 throw new IOException("fail to upload");
               }
               }
           }
        }
         catch (IOException e){
           out.println(e);
         }
         catch (FileUploadException e){
              out.println(e);
         }

//  保存上传的文件到指定的目录

//  在下文中上传文件至数据库时，将对这里改写

    }


 /**
  * Initialization of the servlet. <br>
  *
  * @throws ServletException if an error occure
  */
 public void init() throws ServletException {
  // Put your code here
 }

}

对应的请求文件：

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>index.html</title>

    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="this is my page">

    <!--<link rel="stylesheet" type="text/css" href="./styles.css">-->

  </head>

  <body>
   <form action="./servlet/FileUpload" method="post" enctype="multipart/form-data" name="form1">
  <input type="file" name="file">
  <input type="submit" name="Submit" value="upload">
</form>
   <form action="./servlet/HelloWord" method="post">
    <input type="submit"/>
    </form>
    <form name="uploadform" method="POST" action="./servlet/FileUpload" ENCTYPE="multipart/form-data">

        <table border="1" width="450" cellpadding="4" cellspacing="2" bordercolor="#9BD7FF">

        <tr><td width="100%" colspan="2">

                        文件1：<input name="x" size="40" type="file">

        </td></tr>

        <tr><td width="100%" colspan="2">

                        文件2：<input name="y" size="40" type="file">

        </td></tr>

        <tr><td width="100%" colspan="2">

                        文件3：<input name="z" size="40" type="file">

        </td></tr>

        </table>

        <br/><br/>

        <table>

        <tr><td align="center"><input name="upload" type="submit" value="开始上传"/></td></tr>

       </table>

</form>

  </body>
</html>