问如何连接php和android以检索数据库表中的所有数据

EN

public class MainActivity extends Activity {

TextView tv;
 @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
   StrictMode.enableDefaults();  
    tv=(TextView)findViewById(R.id.tv);
    getData();
}
public void getData(){
 String result= "";
InputStream isr= null;
try{
HttpClient httpclient=new DefaultHttpClient();
HttpPost httppost= new HttpPost("http://your_ip_address/php_filename.php");// your ip address  and php file name here 
HttpResponse response=httpclient.execute(httppost);
HttpEntity entity= response.getEntity();
isr=entity.getContent();

}
 catch(Exception e){
     Log.e("log_tag", "Error in http connection "+e.toString());
     tv.setText("Couldnt connect to database");
 }
//convert response to string

try{
     BufferedReader reader = new BufferedReader(new InputStreamReader(isr,"iso-8859-1"),8);
     StringBuilder sb = new StringBuilder();
     String line = null;
     while ((line = reader.readLine()) != null) {
             sb.append(line + "\n");
     }
     isr.close();

     result=sb.toString();
 }
 catch(Exception e){
     Log.e("log_tag", "Error  converting result "+e.toString());
}

 //parse json data
try {
   String s = "";
   JSONArray jArray = new JSONArray(result);

   for(int i=0; i<jArray.length();i++){
       JSONObject json = jArray.getJSONObject(i);
       s = s + 
               "ID : "+json.getString("CITY_ID") +"\n"+

               "NAME : "+json.getString("CITY_NAME")+"\n\n";
   }

   tv.setText(s);

} catch (Exception e) {
// TODO: handle exception
   Log.e("log_tag", "Error Parsing Data "+e.toString());
}

}

}