www.x158.cn这是一个信息发布网站，他的登陆页面是在www.x158.cn/bg/login.asp
以下是利用httpclient做的一个自动登陆程序。
package test;

import java.io.IOException;

import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.NameValuePair;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;

public class PostForm {

    public static void main(String[] args) throws HttpException, IOException {
        UserPwd userpwd = new UserPwd("ucanhealth", "1234567");
        Zh zh = new Zh();
        System.out.println(zh.iso2utf(userpwd.getInfo())); // 打印返回结果

    }
}

class UserPwd {
    String user, pwd;

    public UserPwd(String user, String pwd) // 构造函数
    {
        this.user = user;
        this.pwd = pwd;
    }

    public String getInfo() {

        HttpClient client = new HttpClient();
        client.getHostConfiguration().setHost("www.x158.cn", 80, "http"); // url的地址，端口，协议
        PostMethod post = new PostMethod("/bg/login.asp"); // 执行查询的网页
        post.addParameter(new NameValuePair("username", user));// 传递文本框的name及values
        post.addParameter("password", pwd);// 传递文本框的pwd及values

        String s = null;
        try {

            int i = client.executeMethod(post);
            System.out.println("record statuscode:" + i);
            s = post.getResponseBodyAsString();

///////////////////////////////////////////////////////////////////////////            
            //检查是否重定向

            int statuscode = post.getStatusCode();

            if ((statuscode == HttpStatus.SC_MOVED_TEMPORARILY) ||

                (statuscode == HttpStatus.SC_MOVED_PERMANENTLY) ||

                (statuscode == HttpStatus.SC_SEE_OTHER) ||

                (statuscode == HttpStatus.SC_TEMPORARY_REDIRECT))
            {

//    读取新的URL地址

                Header header = post.getResponseHeader("location");

                if (header != null) {

                    String newurl = header.getValue();

                    if ((newurl == null) || (newurl.equals("")))
                        

                        newurl = "/";

                    GetMethod redirect = new GetMethod(newurl);

                    client.executeMethod(redirect);

                    System.out.println("Redirect:"+ redirect.getStatusLine().toString());
              

                    redirect.releaseConnection();

                } else

                    System.out.println("Invalid redirect");

            }


//////////////////////////////////////////////////////////////////////////            
            
            
        

        } catch (HttpException e) {

            e.printStackTrace();
        } catch (IOException e) {

            e.printStackTrace();
        }

        return s;
    }

    class GetInfo {
        private String url;

        GetInfo(String url) {
            this.url = url;

        }

        void getInfo() throws IOException {
            String html = null;
            HttpClient hc = new HttpClient();
            // create get method instance
            GetMethod gm = new GetMethod(url);
            // 使用系统提供的默认的恢复策略
            gm.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
                    new DefaultHttpMethodRetryHandler());
            try {
                int statuscode = hc.executeMethod(gm);
                if (statuscode != HttpStatus.SC_OK) {
                    System.err.print("method failed:" + gm.getStatusLine());
                    
                }
                byte[] responseBody = gm.getResponseBody();
                html = new String(responseBody);

            } catch (HttpException e) {
                System.out.println("Please check your provided http address!");
                e.printStackTrace();
            }

            System.out.println(html);
        }
    }

}