مشکل در اتصال به سرور

من تو اتصال به سرور یه مشکلی دارم

دارم از sdk 23 استفاده میکنم برای اتصال اومدم کد زیر رو تو gradle اضافه کردم که بتونم از کلاس HttpClient استفاده کنم

compile 'org.jbundle.util.osgi.wrapped:org.jbundle.util.osgi.wrapped.org.apache.http.client:4.1.2'

و مثل آموزش ها کد زیر رو نوشتم

package ir.google_source.app.my.salar.myapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        HttpClient client = new DefaultHttpClient();
        HttpPost method = new HttpPost("http://google.com");
        try{
            HttpResponse response = client.execute(method);
            int code = response.getStatusLine().getStatusCode();
            Log.i("LOG","colde: " + code);
        }
        catch (ClientProtocolException e){
            e.printStackTrace();
        }
        catch (IOException e){
            e.printStackTrace();
        }
    }
}

ولی این اررور رو گرفتم

06-01 12:38:40.554 20310-20310/ir.google_source.app.my.salar.myapp E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                     Process: ir.google_source.app.my.salar.myapp, PID: 20310
                                                                                     java.lang.RuntimeException: Unable to start activity ComponentInfo{ir.google_source.app.my.salar.myapp/ir.google_source.app.my.salar.myapp.MainActivity}: android.os.NetworkOnMainThreadException
                                                                                         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                                                                                         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                                         at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                                                                                         at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                         at android.os.Looper.loop(Looper.java:148)
                                                                                         at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                                         at java.lang.reflect.Method.invoke(Native Method)
                                                                                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                                      Caused by: android.os.NetworkOnMainThreadException
                                                                                         at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)
                                                                                         at java.net.InetAddress.lookupHostByName(InetAddress.java:431)
                                                                                         at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
                                                                                         at java.net.InetAddress.getAllByName(InetAddress.java:215)
                                                                                         at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:142)
                                                                                         at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:169)
                                                                                         at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:124)
                                                                                         at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:366)
                                                                                         at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:560)
                                                                                         at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:492)
                                                                                         at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:470)
                                                                                         at ir.google_source.app.my.salar.myapp.MainActivity.onCreate(MainActivity.java:25)
                                                                                         at android.app.Activity.performCreate(Activity.java:6237)
                                                                                         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
                                                                                         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
                                                                                         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                                         at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                                                                                         at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                         at android.os.Looper.loop(Looper.java:148)
                                                                                         at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                                         at java.lang.reflect.Method.invoke(Native Method)

اومدم از URLConnection به صورت زیر استفاده کردم بازهم همین ارور رو داد

     public static String getContents(String url) {
        String contents = "";

        try {
            URLConnection conn = new URL(url).openConnection();

            InputStream in = conn.getInputStream();
            contents = convertInputStreamToString(in);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return contents;
    }

    private static String convertInputStreamToString(InputStream inputStream) {
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            StringBuilder builder = new StringBuilder();

            String line = "";

            while ((line = reader.readLine()) != null) {
                builder.append(line);
            }

            return builder.toString();
        }
        catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

مشکل کجاست؟