我的源代码如下:
GetSample.java

package test;
import java.io.IOException;
import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;

public class GetSample{
    String id="";
    String psw="";
    public void id(String id){
        id=this.id;
    }
    
    public void psw(String psw){
        psw=this.psw;
    }
    
  public  byte[] doit(String url) {
  //构造HttpClient的实例
  HttpClient httpClient = new HttpClient();
  //创建GET方法的实例
  GetMethod getMethod = new GetMethod(url);
  //使用系统提供的默认的恢复策略
  getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
    new DefaultHttpMethodRetryHandler());
  try {
   //执行getMethod
   int statusCode = httpClient.executeMethod(getMethod);
   if (statusCode != HttpStatus.SC_OK) {
    System.err.println("Method failed: "
      + getMethod.getStatusLine());
   }

   return getMethod.getResponseBody();
   
  } catch (HttpException e) {
   return new  byte[123];
  } catch (IOException e) {
   //发生网络异常
      return new  byte[456];
  } finally {
   //释放连接
   getMethod.releaseConnection();
  }
 }
}

dologin.jsp

<%@ page language="java" contentType="text/html; charset=gb2312"
    pageEncoding="gb2312"%>

<!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=gb2312">
<title>Insert title here</title>
</head>
<body>
<jsp:useBean id="GetSample" class="test.GetSample" scope="page">
</jsp:useBean>
<%
byte[] html;
String url="http://www.hpedi.com.cn";
html=GetSample.doit(url);
if(html==null){
    out.print("wrong");
}else{
out.println(html);
}
%>
</body>
</html>

在eclipse 上没出错

打开网页出错如下:

type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

org.apache.jasper.JasperException: Exception in JSP: /dologin.jsp:16

13: <%
14: byte[] html;
15: String url="http://www.hpedi.com.cn";
16: html=GetSample.doit(url);
17: if(html==null){
18:     out.print("wrong");
19: }else{


Stacktrace:
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:467)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:371)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


root cause 

javax.servlet.ServletException: org/apache/commons/codec/DecoderException
    org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:846)
    org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:779)
    org.apache.jsp.dologin_jsp._jspService(dologin_jsp.java:81)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


root cause 

java.lang.NoClassDefFoundError: org/apache/commons/codec/DecoderException
    org.apache.commons.httpclient.HttpMethodBase.<init>(HttpMethodBase.java:220)
    org.apache.commons.httpclient.methods.GetMethod.<init>(GetMethod.java:89)
    test.GetSample.doit(GetSample.java:22)
    org.apache.jsp.dologin_jsp._jspService(dologin_jsp.java:66)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


note The full stack trace of the root cause is available in the Apache Tomcat/5.5.23 logs.


请高手指教!!!无限感激!!
[em1][em1]