httpclient 实现模拟登陆的问题

我想用httpclient 做一个摸模拟登陆人人网（就是类似的网站，要输入用户名密码的那种，论坛啦网友啦）的应用程序，我知道用httpclient的post方法实现向服务器提交参数（账户名和密码）的方法，可是接下来我要怎样才能知道我是否登陆成功了呢？如果登录成功就放会“登陆成功！”反之则返回“登录失败！”我要如何通过服务器返回来的信息获得是否登录成功的信息呢？希望给位大侠能不吝赐教啊！

httpclient 模拟登陆网站 获取网站内容程序
package org.apache.http.examples.client;

import java.io.IOException;

import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.cookie.*;
import org.apache.commons.httpclient.methods.*;

public class FormLoginDemo {
static final String LOGON_SITE = "www.intellitrans.com.cn";
static final int LOGON_PORT = 8081;
static final String loginurl = "/zyzg/logon.do";
static final String loginparematername = "userName";
static final String loginparematerpass = "password";
static final String username = "wangpx";
static final String password = "111111";

static final String getUrl = "/zyzg/hrmsub/hrm-deptlist.do";


public static void main(String[] args) throws Exception {
    HttpClient client = imitateLogin(LOGON_SITE, LOGON_PORT, loginurl, loginparematername, loginparematerpass, username, password);
    // 访问所需的页面
    imitateGetUrl(client, getUrl);
}

//模拟等录 
private static HttpClient imitateLogin(String LOGON_SITE, int LOGON_PORT,
        String loginurl,String loginparematername,String loginparematerpass,String username,String password) throws IOException, HttpException {
    HttpClient client = new HttpClient();
    client.getHostConfiguration().setHost(LOGON_SITE, LOGON_PORT);
    // 模拟登录页面
    PostMethod post = new PostMethod(loginurl);
    NameValuePair name = new NameValuePair(loginparematername,username );
    NameValuePair pass = new NameValuePair(loginparematerpass,password );
    post.setRequestBody(new NameValuePair[] { name, pass });
    int status = client.executeMethod(post);
    System.out.println(post.getResponseBodyAsString());
    post.releaseConnection();
    // 查看cookie信息
    CookieSpec cookiespec = CookiePolicy.getDefaultSpec();
    Cookie[] cookies = cookiespec.match(LOGON_SITE, LOGON_PORT, "/", false,
            client.getState().getCookies());
    if (cookies != null)
        if (cookies.length == 0) {
            System.out.println("None");
        } else {
            for (int i = 0; i < cookies.length; i++) {
                System.out.println(cookies[i].toString());
            }
        }
    return client;
}
//模拟等录 后获取所需要的页面
private static void imitateGetUrl(HttpClient client, String getUrl)
        throws IOException, HttpException {
    PostMethod post2 = new PostMethod(getUrl);
    // GetMethod get = new
    // GetMethod("/social/article/gallery_show/p_104846/");
    client.executeMethod(post2);
    System.out.println(post2.getResponseBodyAsString());
    post2.releaseConnection();
}

}

[quote]如果登录成功就放会“登陆成功！”反之则返回“登录失败！[/quote]

如果登录成功，会返回200响应码的，失败会返回其它响应码。

通过HTML页面的值，

你可以先在浏览器里测试登录成功与登录失败返回的页面

在查看源文件里
找出登录成功的HTML与登录失败的HTML有哪段可以区分开来的代码。

拿出这段代码。

放到你的JAVA代码里，

当你用JAVA登录后，应该会返回一个流，
你把流里的内容转成STRING或其他，
通过判断是否包含你所COPY的代码来判断登录成功与否

我来讲讲，登录失败后，返回的字符流是人人网的登录页面源码。
第一，登录成功后，返回的肯定是个人首页html代码。
第二，登录失败后，首先我们想想，在网页（renren.com）上登录，我们清楚登录失败后页面跳转到[color=red]带有错误提示[/color]的登录页面，说明什么？说明返回的字符流就是“带有错误提示的登录页面”。
现在明白了，返回时什么了吧，

然后来测试一下，下面使用的是c#代码测试（java代码上面有）；

下面是我的测试代码：

[code="c#"]/////////////////////////////////////////////
//自动填充登陆信息，并提交
//人人网登陆
/////////////////////////////////////////////
string email =163@163.com;//用户名样例
string password = 12345;//密码样例
string autoLogin = "true";
string origURL = "http://www.renren.com/Home.do";
string domain = "renren.com";
//将文本转换为URL编码字符串
email = System.Web.HttpUtility.UrlEncode(email);
password = System.Web.HttpUtility.UrlEncode(password);
autoLogin = System.Web.HttpUtility.UrlEncode(autoLogin);
origURL = System.Web.HttpUtility.UrlEncode(origURL);
domain = System.Web.HttpUtility.UrlEncode(domain);

        //格式要提交的字符串数据
        string formatString = "email={0}&password={1}&autoLogin={2}&origURL={3}&domain={4}";
        string postString = string.Format(formatString, email, password, autoLogin,origURL,domain);

        //将提交的字符串数据转换成字节数组
        byte[] postData = Encoding.ASCII.GetBytes(postString);

        //设置提交的相关参数

        string URI = "http://www.renren.com/PLogin.do";
        HttpWebRequest request = WebRequest.Create(URI) as HttpWebRequest;
        request.Method = "POST";
        request.KeepAlive = false;
        request.ContentType = "application/x-www-form-urlencoded";
        request.CookieContainer = cookieContainer;
        request.ContentLength = postData.Length;

        // 提交请求数据
        System.IO.Stream outputStream = request.GetRequestStream();
        outputStream.Write(postData, 0, postData.Length);
        outputStream.Close();

        // 接收返回的页面
        HttpWebResponse response;
        response = request.GetResponse() as HttpWebResponse;
       System.IO.Stream responseStream = response.GetResponseStream();
        System.IO.StreamReader reader = new System.IO.StreamReader(responseStream, Encoding.UTF8);
       string srcString = reader.ReadToEnd();

       Console.Write(srcString+"测试返回代码");

[/code]

测试结果：返回就是带有错误提示的登录页面代码。