import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

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

        //Verbose  Log.v()
        //Debug    Log.d()
        //Info     Log.i()
        //Warning  Log.w()
        //Error    Log.e()

        Log.v(TAG, "C'est un log verbose");
        Log.w(TAG, "Attention, il y un probleme");
    }
}