Hello World Application in Android

File Name: activity_main.xml
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <TextView android:text="@string/hello_world" android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/hello"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:textSize="30sp" />
</RelativeLayout>

File Name: MainActivity.java

package com.example.abbu.helloworld;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;


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

File Name: strings.xml

<resources>
    <string name="app_name">Hello World</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>
</resources>



Output:
Hello World Application in Android