مشکل در ایجاد درخواست

[game100]

با سلام من خوام یک درخواست به صورت get ارسال کنم کدشم نوشتم ولی اجرا نمیشه ؟؟

package com.example.samplehttp;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URL;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void btn1(View v)
{

try{

String username = "admin";
String password = "admin";
String link = "http://192.168.216.1/Android/server.php?username="
+username+"&password="+password;
URL url = new URL(link);
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(link));
HttpResponse response = client.execute(request);
BufferedReader in = new BufferedReader
(new InputStreamReader(response.getEntity().getContent( )));

StringBuffer sb = new StringBuffer("");
String line="";
while ((line = in.readLine()) != null) {
sb.append(line);
break;
}
in.close();
//return sb.toString();
}catch(Exception e){
TextView tv=(TextView) findViewById(R.id.textView1);
tv.setText("faile");
}
}

}




و اینم کد صفحه مورد نظر

<؟php
$con=mysqli_connect("localhost","root","","my_db");
$sql="INSERT INTO table1 (Username, Password, Role) VALUES ('".$_GET['username']."', '".$_GET['password']."','mod')";
if(isset($_GET['username']) && isset($_GET['password']))
{
if (mysqli_query($con,$sql))
{
echo "Values have been inserted successfully";
}
}
?>


نمی دونم مشکلش از کجاست ؟؟