Getting started with Android in the command line

Posted by Abdul | Tue, 14 Jun 2011 | Tagged: java, mobile, android, tutorial

Android applications can be created using the command line itself. Necessary tools are provided by the Android SDK. This article will demonstrate how to create a Android Application in the command line.

Setting up the Work Environment

The Android SDK is required for developing a Android application from command line. Download the latest Android SDK from the link http://developer.android.com/sdk/index.html.

The PATH environment variable should be setup, to work with the Android SDK. Add the following directories to the PATH environment variable. You might want to add it to your .bashrc file.

/path/to/android/sdk/tools
/path/to/android/sdk/platform-tools

Creating Android Virtual Device

The android command is invoked for setting up projects, AVDs, etc. The general syntax of the android command for creating an AVD is given below.

$ android create avd -n {emulator name} -t {target ID}

The emulator name is the name assigned to the AVD. The target ID requires a bit more explanation.

The Android SDK maintains a set of system images, each containing a specific version of Android and other additional libraries. Each system image is identified by a unique no. called the target ID. The list of available targets can be listed using the following command.

$ android list targets
id: 1 or "android-3"
     Name: Android 1.5
     Type: Platform
     API level: 3
     Revision: 4
     Skins: QVGA-L, HVGA-L, HVGA (default), HVGA-P, QVGA-P
...

The command create a AVD with the name galaxy and using target ID 8 is give n below.

$ android create avd -n galaxy -t 8

Starting AVD

After creating the AVD, the AVD can be started using the emulator command. The general syntax of the command is given below.

$ emulator -avd {emulator name}

The command to start the AVD galaxy is given below.

$ emulator -avd galaxy

Creating new project

The general syntax of the android command for creating a project is given below.

$ android create project --target {target id}
  --package {package name} --activity {activity name}
  --path {path to project folder}

The package name, is the Java package name to be used in this project. The activity name, is the name for the Activity class. As with the AVD creation, the target ID refers to a system image.

An example command to create an activity called Hello is given below.

$ android create project --target 8
  --package com.hello  --activity Hello
  --path /home/abdul/android_practice/hello

The above step will create the project folder with necessary files inside it. The project structure and the file details have been explained in the article Getting Started with Android. Modify main.xml and Hello.java as specified in the previous article.

Build `.apk` file using Ant tool

Android projects are built using the Ant tool. Ant is java library and command-line tool used to build the java application. For building Android Application the required version of ant tool is 1.8.0 or later can be obtained from http://ant.apache.org/srcdownload.cgi.

Enter into the project folder and invoke ant as shown below.

$ ant -Dsdk.dir={path to android sdk} release

The above step will create R.java file located in the gen folder and .apk file located in bin folder. The .apk file is the Android package file, equivalent to .jar files in Java SE.

Installing .apk file in emulator

Ensure the AVD is running and install the .apk file, using the Android Debugger. The Android Debugger is invoked using the adb command. The general syntax for installing Android packages is given below.

$ adb install {.apk file}

After the Android application is installed in the emulator, the application has to be started manually. In the emulator window

Press the menu icon.

Figure 1. AVD displaying menu icon
Search and select your installed application.

Figure 2. AVD displaying Hello Application icon