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有关FileUpload组件的使用和调试的经验


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 erver\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.InvocationTargetExceptionatorg.apache.commons.fileupload.FileUpload.createItem(FileUpload.java:615)atorg.apache.commons.fileupload.FileUpload.parseRequest(FileUpload.java:474)atorg.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>注:该代码由部分来自网上!
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