Setting Up the Android Development Environment and Creating Your First App Project

After configuring the Android SDK, we will now create our first Android application project. This process will help you become familiar with using the development environment and understanding the basic project structure. This article will guide you step-by-step through creating a simple “Hello World” application.

1. Launch Android Studio

First, ensure that Android Studio is installed on your system. Launch Android Studio, and you’ll see the welcome screen. Select “Start a new Android Studio project” to begin creating a new project.

2. Choose a Project Template

In the “Choose your Project” screen, you’ll see several project templates. For this tutorial, select the “Empty Activity” template — it provides the minimal foundation for building a simple app.

3. Configure Your Project

In the “Configure your project” screen, enter the following information:

• Name: Enter your app’s name—for example, HelloWorld.
• Package name: By default, this is auto-generated based on your app name—for example, com.example.helloworld.
• Save location: Choose the folder where you’d like to save your project.
• Language: Select your preferred programming language. We recommend either Java or Kotlin; in this guide, we’ll use Java.
• Minimum API level: Choose the lowest Android API level your app will support. We recommend API 21: Android 5.0 (Lollipop) as a practical minimum.

Once all fields are filled, click “Finish” to complete project creation.

4. Understand the Project Structure

After creation, Android Studio opens your new project. You’ll see several key directories and files:

• app/src/main/java/: Contains your app’s Java source code.
• app/src/main/res/: Contains your app’s resources—such as layouts (layout/), images (drawable/), strings (values/), etc.
• app/src/main/AndroidManifest.xml: The app’s configuration file, declaring essential metadata and components (e.g., activities, permissions).

5. Edit the Layout File

Navigate to app/src/main/res/layout/ and locate the activity_main.xml file. Open it and define the UI layout using XML. Replace its contents with the following to display “Hello World” centered on screen:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World"
        android:layout_centerInParent="true"
        android:textSize="24sp"/>
</RelativeLayout>

Here, we use a TextView to display the text “Hello World”, centered within its parent container.

6. Modify the Java Code

Next, open the MainActivity.java file and ensure its content matches the following:

package com.example.helloworld;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;

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

This code declares MainActivity as a subclass of AppCompatActivity. In the onCreate() method, it calls setContentView() to inflate and display the layout defined in activity_main.xml.

7. Run the App

You’ve now completed the basic app setup. Ensure your Android Virtual Device (AVD) is running—or that a physical Android device is connected and properly configured for development. Click the green “Run” button in the toolbar, then select your target device. Android Studio will compile the app and launch it automatically.

You should see a screen displaying “Hello World”—a clear sign that your first Android app project has been successfully created and executed.

8. Summary

In this chapter, after completing the development environment setup, we created a simple Android app project and explored its fundamental structure—including how to edit layout files. In the next chapter, we’ll dive into essential Java fundamentals to lay a solid foundation for robust Android application development. Keep learning—and let’s build more sophisticated apps together!