Android supported Java8 features

• default and static methods in Interfaces
• default and static methods can be declared in Interfaces declarations. These methods don't need to be implemented by the Classes that are implementing those interfaces. static methods are attached to the Interface and Classes which implements such interfaces.
• Reference: https://docs.oracle.com/javase/tutorial/java/IandI/defaultmethods.html
• Repeating Annotations
• Now one annotation can be used multiple times on a specific target.
• Reference: https://docs.oracle.com/javase/tutorial/java/annotations/repeating.html
• Lambda expressions:
• Lambda expressions enable to treat functionality as method argument or code as data.
• Lambda exp is useful especially to define anonymous class with one method
• Reference: https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html
• Syntax for Lambda expressions: https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html#syntax

Terms:

• Functional interfaces: An interface with only method is called as functional interfaces. JDK defines few built-in functional interfaces in package: java.util.function 

How to setup Signing configuration in Android Studio/Gradle

Add following to your build.gradle :

android {

defaultConfig {}

signingConfigs {

   release {
      storeFile file("<path-to-signing-keys>/signingKeys.jks")
      storePassword "your store password"      keyAlias "your chosen alias"      keyPassword "password"
   }

}

You can also publish to playtore by adding following configuration to your build.gradle:



play {
    serviceAccountEmail = 'serviceAccount@gmail.com'    pk12File = file('key.p12')
    track = 'alpha'}

Starting android emulator using commandline

Emulator can be started using command line using:

emulator -avd <name>

Automatic publishing apk to Google Play Store Developer Console using Jenkins

1. Jenkins plugins:
1. Google Play Publishing plugins (only works on Jenkins version > 1.6.09)
2. Jenkins Build job
1. Separate build job for each flavor of apk
2. Create Free style build job in jenkins as described here.
3. Configure Service Account on Google Play Store as shown here.

Android Testing using ATSL (Android Testing Support Library)

Running instrumented unit tests
Instrumented unit tests are important when a functionality can't be tested using mock objects.

Tools used
AndroidJunitRunner is used to run such tests.

Configuring build.gradle

defaultConfig {
applicationId "appId" minSdkVersion 17 targetSdkVersion 23 versionCode 1
versionName "1.1"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"}

Dependencies

dependencies {
compile 'com.android.support:support-annotations:23.0.1' compile 'com.android.support:appcompat-v7:23.0.1'

androidTestCompile 'junit:junit:4.12' androidTestCompile 'com.android.support:support-annotations:23.0.1' androidTestCompile 'com.android.support.test:runner:0.4.1' androidTestCompile 'com.android.support.test:rules:0.4.1'
}

Running Instrument tests:

gradlew connectedAndroidTest

Useful links:

• Android Testing Support Library
• Android Testing Code Lab
• Android Testing Best Practices
• Android Testing Tools

How to access build version from build.gradle from Java class

Its available in BuildConfig.java.

So simply access version name like this:

BuildConfig.VERSION_NAME

And Version code could be accessed like this:

BuildConfig.VERSION_CODE 

How to publish artifacts (Android Library in "aar" format) to Maven repo from Android Studio gradle

This post shows build.gradle configuration to be able to push artifacts to local Maven repo. I've taken Android library in its "aar" format as artifact for example.

First add "maven-publish" plugin to enable publishing artifacts from build.gradle:

apply plugin: 'maven-publish'

Don't forget to add local maven repo:

repositories {
    mavenLocal()
}

Add publishing block now:

publishing {
    publications {
        mavenJava(MavenPublication) {
            groupId <GROUP_ID>
            artifactId <ARTIFACT_ID>
            version <currentVersion>

            artifacts = ["${buildDir}/outputs/aar/<your_android_library>.aar"]
        }
    }
}