Step to creating new application in Eclipse

Create Android Application

The first step is to create a simple Android Application using Eclipse IDE. 
Follow the option File -> New -> Project and finally select Android New Application wizard from the wizard list. 

Android project directories and files 

src

This contains the .java source files for your project. By default, it includes a MainActivity.java source file having an activity class that runs when your app is launched using the app icon.

gen

This contains the .R file, a compiler-generated file that references all the resources found in your project. You should not modify this file.

bin

This folder contains the Android package files .apk built by the ADT during the build process and everything else needed to run an Android application.

res/drawable-hdpi

res/drawable-xhdpi

res/drawable-xxhdpi

res/drawable-xxxhdpi

This is a directory for drawable objects that are designed for density wise screens.

res/layout

This is a directory for files that define your app's user interface.

res/values

This is a directory for other various XML files that contain a collection of resources, such as strings and colours definitions.

AndroidManifest.xml

This is the manifest file which describes the fundamental characteristics of the app and defines each of its components.

MainActivity.jav

package com.example.myapplication;

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);

}

@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;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

// Handle action bar item clicks here. The action bar will

// automatically handle clicks on the Home/Up button, so long

// as you specify a parent activity in AndroidManifest.xml.

int id = item.getItemId();

if (id == R.id.action_settings) {

return true;

}

return super.onOptionsItemSelected(item);

}

}

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:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.example.myapplication.MainActivity" >

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/hello_world" />

</RelativeLayout>

String.xml

<?xml version="1.0" encoding="utf-8"?>

<resources>

    <string name="app_name">MyApplication</string>

    <string name="hello_world">My First Application</string>

    <string name="action_settings">Settings</string>

</resources>

Manifest File

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.example.myapplication"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="21" />

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

</manifest>

Output