Call a PHP Webservice from android by post method

package com.example.root.myapplication;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.os.AsyncTask;
import android.widget.TextView;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnhitapi=(Button) findViewById(R.id.btnhitapi);
btnhitapi.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new HttpRequestTask().execute();
}
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();

//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}

return super.onOptionsItemSelected(item);
}

private class HttpRequestTask extends AsyncTask {
@Override
protected Greeting doInBackground(Void… params) {
try {
HttpClient httpClient = new DefaultHttpClient();
HttpPost post = new HttpPost(“http://infinitywebinfo.com/cricketapp/user/apitest”);
//post.setHeader(“content-type”, “application/json”);

List nameValuePairs = new ArrayList(2);
nameValuePairs.add(new BasicNameValuePair(“username”, “uma”));
nameValuePairs.add(new BasicNameValuePair(“password”, “Hi”));
post.setEntity(new UrlEncodedFormEntity(nameValuePairs));

HttpResponse resp = httpClient.execute(post);
String respStr = EntityUtils.toString(resp.getEntity());

Log.i(“Response”, respStr.toString());
return respStr.toString();

} catch (Exception e) {
Log.e(“MainActivity”, e.getMessage(), e);
}

return null;
}

@Override
protected void onPostExecute(String  result) {
Log.i(“Response”,result);
}

}
}