simple firebase

BelajarFirebase.java

package com.ocit.wasap.activity;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.firebase.client.DataSnapshot;
import com.firebase.client.Firebase;
import com.firebase.client.FirebaseError;
import com.firebase.client.ValueEventListener;
import com.ocit.wasap.R;

/**
 * Created by ar-android on 03/11/2015.
 */
public class BelajarFirebase extends AppCompatActivity{
    private Button btn1, btn2;
    private TextView tv;
    private Firebase mRef;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.belajar_firebase);
        Firebase.setAndroidContext(this);
    }

    @Override
    protected void onStart() {
        super.onStart();
        btn1 = (Button)findViewById(R.id.btn1);
        btn2 = (Button)findViewById(R.id.btn2);
        tv = (TextView)findViewById(R.id.tvAhmadRosid);

        mRef = new Firebase("https://belajarfierebase.firebaseio.com/ahmadrosid");
        mRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                String newAhmadrRosid = (String)dataSnapshot.getValue();
                tv.setText(newAhmadrRosid);
            }

            @Override
            public void onCancelled(FirebaseError firebaseError) {

            }
        });

        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mRef.setValue("Ahmad");
            }
        });

        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mRef.setValue("Rosid");
            }
        });
    }
}