在模擬登陸之前做的準備工作就是利用抓包工具分析資料，推薦用wireshark。本次抓openid.org.cn，純屬演示，沒實際意義，切勿搞破壞或者偷資料。

抓包下來的資料如下：

看來OpenID沒做什麼安全機制方面的考慮，就單純的講文字域username,password post到www.openid.org.cn/login上。

OK。萬事俱備只欠東風，開始模擬登陸吧。

package test;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;

public class SimulateLogin {

	    private HttpClient httpClient;  
	  
	    public SimulateLogin(String loginURL,String userName, String password) {  
	        this.httpClient = new DefaultHttpClient();  
	        // 構造一個POST請求
	        HttpPost httpPost = new HttpPost(loginURL);  
	        //httpPost.setHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/534.3 (KHTML, like Gecko) Chrome/6.0.472.63 Safari/534.3");    //如果對方系統沒做特殊限制，可不用
	        // 將要POST的資料封包  
	        List<NameValuePair> params = new ArrayList<NameValuePair>();  
	        params.add(new BasicNameValuePair("username", userName));  
	        params.add(new BasicNameValuePair("password", password));  
	  
	        // 封包新增到Post請求  
	        try {  
	            httpPost.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));  
	        } catch (UnsupportedEncodingException e1) {  
	            e1.printStackTrace();  
	        }
	        HttpResponse response = postMethod(httpPost); 
	    }  
	  
	    /**
	     * 嗅探指定的GET頁面
	     * @param url
	     * @return String txt
	     */
	    public String notifyGetPage(String url) {  
	        HttpGet get = new HttpGet(url);  
	        ResponseHandler<String> responseHandler = new BasicResponseHandler();  
	        String txt = null;  
	        try {  
	            txt = httpClient.execute(get, responseHandler);  
	        } catch (ClientProtocolException e) {  
	            e.printStackTrace();  
	        } catch (IOException e) {  
	            e.printStackTrace();  
	        } finally {  
	            get.abort();  
	        }  
	        return txt;  
	    }  
	    
	    /**
	     * 嗅探指定的POST頁面,，因為post方法要封裝引數，因此在函式外部封裝好傳參  
	     * @param post
	     * @return String txt
	     */ 
	    public String notifyPostPage(HttpPost post) {  
	        ResponseHandler<String> responseHandler = new BasicResponseHandler();  
	        String txt = null;
	        try {  
	        	txt = httpClient.execute(post,responseHandler);  
	        } catch (ClientProtocolException e) {  
	            e.printStackTrace();  
	        } catch (IOException e) {  
	            e.printStackTrace();  
	        } finally {  
	            post.abort();  
	        }  
	        return txt;  
	    }
	  
	    // 用post方法向伺服器請求 並獲得響應，因為post方法要封裝引數，因此在函式外部封裝好傳參  
	    public HttpResponse postMethod(HttpPost post) {  
	        HttpResponse resp = null;  
	        try {  
	            resp = httpClient.execute(post);  
	        } catch (ClientProtocolException e) {  
	            e.printStackTrace();  
	        } catch (IOException e) {  
	            e.printStackTrace();  
	        } finally {  
	            post.abort();  
	        }  
	        return resp;  
	    }
	  
	    // 用get方法向伺服器請求 並獲得響應  
	    public HttpResponse getMethod(String url) {  
	        HttpGet get = new HttpGet(url);  
	        HttpResponse resp = null;  
	        try {  
	            resp = httpClient.execute(get);  
	        } catch (ClientProtocolException e) {  
	            e.printStackTrace();  
	        } catch (IOException e) {  
	            e.printStackTrace();  
	        } finally {  
	            get.abort();  
	        }  
	        return resp;  
	    }  
	  
	    public static void main(String[] args) {  
	    	SimulateLogin simulateLogin = new SimulateLogin("http://www.openid.org.cn/login","【使用者名稱】", "【密碼】");  
	        System.out.println(simulateLogin.notifyGetPage("http://www.openid.org.cn/sites"));  //獲得我訪問過的站點資訊
	    }  
	
}
 

很簡單吧..這是最簡單的登陸，如果站點用到驗證碼，或者用JS加密字串，SSL的話，肯定會讓你折騰大半天的。。