Android开发中使用PHP服务器怎么实现一个登录功能

package com.itcast.test03;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends Activity {
 private EditText et_username;
 private EditText et_userPsd;
 private Button login;
 private Button signUp;
 private CheckBox save;
 private String user,pass;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);  
  setContentView(R.layout.activity_main);
  et_username = (EditText)findViewById(R.id.et_number);
  et_userPsd = (EditText)findViewById(R.id.et_password);
  login=(Button)findViewById(R.id.login);
  signUp=(Button)findViewById(R.id.signUp);
  save = (CheckBox)findViewById(R.id.save);  
  //登录按钮的点击事件
  login.setOnClickListener(new View.OnClickListener() {
   
    @Override
    public void onClick(View v) {
    // TODO Auto-generated method stub
    
     //将输入的用户名和密码转换成字符串
    String name =et_username.getText().toString();
    String pwd = et_userPsd.getText().toString();
     //调用login方法
    login(name, pwd);
    }
    });
    }
    
    private void login(final String name, final String pwd){
     //创建Handler对象
    final Handler handler = new Handler() {
     
    public void handleMessage(Message msg) {
    if(msg.what == 1){
     Toast.makeText(MainActivity.this, "登录成功", Toast.LENGTH_SHORT).show();
     //提示登陆成功
     finish();
    }else if(msg.what == 0){
     Log.i(name, msg.toString());
    }else if(msg.what == -1){
     Log.i("==============",msg.toString());
    }
    }
    };
    new Thread(){
    public void run() {
     //创建Message对象
    Message msg =new Message();
    try {
     Post po = new Post();
     String infoo = po.logina(name, pwd);
        if(infoo != null){
        msg.what = 1;//成功
        msg.obj = infoo;
        }else{
        msg.what = 0;//失败
        msg.obj = "2";
        }
       } catch (Exception e) {
       e.printStackTrace();
     msg.what = -1;
     msg.obj = e;
       }
    handler.sendMessage(msg);
    }
    }.start();
    }
 }

package com.itcast.test03;
import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.ParseException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

public class Post {
 
 public String logina(String name, String pwd)throws ParseException, IOException, JSONException{
   //获取到HttpClient对象
   HttpClient httpClient = new DefaultHttpClient();
   String strurl = "http://10.6.78.213:2016/xampp/sse/index.php/home/Index/server_info";
   HttpPost request = new HttpPost(strurl);
   request.addHeader("Accept","application/json");
   request.addHeader("Content-Type","application/json");//还可以自定义增加header
   JSONObject param = new JSONObject();//定义json对象
   param.put("sequenceId", "87620056570355357690");
   param.put("accType", "0");
   param.put("loginId", name);
   param.put("password", pwd);
   //param.put("thirdpartyAppId", "");
   //param.put("thirdpartyAccessToken", "");
   param.put("loginType", "1");
   Log.i("===========", param.toString());
   System.out.println("1+===========");
   StringEntity se = new StringEntity(param.toString());
   request.setEntity(se);//发送数据
   HttpResponse httpResponse = httpClient.execute(request);//获得相应
   System.out.println("2+===========");//进行一行一行的调试时无法打印此语句。原因就是无法成功连接到 　　　　　　　　　　　　　　　　　　　　　　　网络
   int code = httpResponse.getStatusLine().getStatusCode();
   System.out.print(code);
   String result = EntityUtils.toString(httpResponse.getEntity());
   JSONObject result1 = new JSONObject(result);
   String info = (String) result1.get("retInfo");
   Log.i("=============", info);
   return info;
   }

}