[Android]Android Hello World Example

In this tutorial, we show you how to create a simple “hello
world” Android project in Eclipse IDE +
ADT plugin, and run it with Android Virtual Device
(AVD). The Eclipse ADT plugin provided easy Android project creation
and management, components drag and drop, auto-complete and many useful features
to speed up your Android development cycles.

Summary steps to develop an Android application :

1. Install Android SDK


2. Install ADT Eclipse plugin


3. Create an Android Virtual Device (AVD)


4. Create Android Project with Eclipse (Wizard)


5. Code it…


6. Start it in Android Virtual Device (AVD)

Tools used in this tutorial :

1. JDK 1.6


2. Eclipse IDE 3.7 , Indigo


3. Android SDK

1. Install Android SDK

Visit this Android
SDK page, choose which platform and install it.

In Android SDK installed folder, run “Android SDK manager”, choose what
Android version you want to develop.

2. Install ADT Eclipse plugin

To integrate Android SDK with Eclipse IDE, you need to install Eclipse ADT
plugin. Refer to this official guide – “Installing the ADT Plugin“.

In Eclipse IDE, select “Help” -> Install New Software…”, and put below URL
:

https://dl-ssl.google.com/android/eclipse/

Note
In my case, above ADT plugin is taking years to
download, no idea why. If you are facing the similar problem, just download and
install the ADT plugin manually, refer to this ADT plugin troubleshooting guide.

3. Create an Android Virtual Device (AVD)

In Eclipse, you can access the “Android Virtual Device
(AVD)” in Eclipse toolbar. Click “new” to create a AVD.

Later, Eclipse will deploy the application into this AVD.

4. Create Android Project

In Eclipse, select “File -> New -> Project….”, “Android Project”, and
input your application detail. Eclipse will create all the necessary Android
project files and configuration.

5. Hello World

Locate the generated activity file, and modify a bit to output a string
“Hello World”.

File : HelloWorldActivity.java

package com.mkyong.android;

import android.app.Activity;

import android.os.Bundle;

import android.widget.TextView;
public class HelloWorldActivity extends Activity {

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
TextView text = new TextView(this);

        text.setText("Hello World, Android - mkyong.com");

        setContentView(text);

    }

}

6. Demo

Run it as “Android Application“, see output.

Press “Home” button (on right hand side), and you will noticed that
“HelloWorld” application is deployed successfully on the Android virtual
device.

Note
This tutorial is more to example driven, not much
explanation. For detail and complete explanation, please refer to the
official Android developer hello world tutorial.

Firewall…
In my computer, the COMODO firewall is
installed and blocked the deploying process, caused the connection between
Eclipse ADT and AVD is blocked and failed to deploy. Just make sure your
firewall is configured properly, or just turn it off for Android development
:)

Debug Android application on real device
Sometime,
“Android Virtual Device” is not enough to test some real phone
functionalities, like led light, sensor and etc. Then you should refer to
this how
to debug Android application on real device.

Download Source Code

Download it – Android-HelloWorld.zip (15
KB)

References

1. Android
   Developers