How to retrieve path to ADB in build.gradle

Question

I trying to start application via gradle task.

task runDebug(dependsOn: ['installDebug', 'run']) {
}

task run(type: Exec) {
commandLine 'adb', 'shell', 'am', 'start', '-n', 'com.example.myexample/.ui.SplashScreenActivity'
}

But this code don't work and i get error:
a problem occurred starting process 'command 'adb''

However, when i specify the path to adb explicitly, application is started.

task run(type: Exec) {
    commandLine 'D:\\android\\android-studio\\sdk\\platform-tools\\adb', 'shell', 'am', 'start', '-n', 'com.example.myexample/.ui.SplashScreenActivity'
}

So how can i get a variable which contains the path and transfer it to commandLine?

Answer 1

You should use the logic that the Android Gradle plugin already has for finding the SDK and adb locations to ensure your script is using the same ones.

# Android Gradle >= 1.1.0
File sdk = android.getSdkDirectory()
File adb = android.getAdbExe()

# Android Gradle < 1.1.0
File sdk = android.plugin.getSdkFolder()
File adb = android.plugin.extension.getAdbExe()

Answer 2

The problem was solved.
The variable must contain

def adb = "$System.env.ANDROID_HOME/platform-tools/adb"

And complete task looks like

task run(type: Exec) {
    def adb = "$System.env.ANDROID_HOME/platform-tools/adb"
    commandLine "$adb", 'shell', 'am', 'start', '-n', 'com.example.myexample/.ui.SplashScreenActivity'
}

UPD
Another way without using ANDROID_HOME

task run(type: Exec) {
    def rootDir = project.rootDir
    def localProperties = new File(rootDir, "local.properties")
    if (localProperties.exists()) {
        Properties properties = new Properties()
        localProperties.withInputStream { 
            instr -> properties.load(instr)
        }
        def sdkDir = properties.getProperty('sdk.dir')
        def adb = "$sdkDir/platform-tools/adb"
        commandLine "$adb", 'shell', 'am', 'start', '-n', 'com.example.myexample/.ui.SplashScreenActivity'
    }
}