Auto Increment Version Number Using Gradle Script For Android Applications

How To Call Auto Increment Method When Build

gradle.taskGraph.whenReady {taskGraph ->
    if (taskGraph.hasTask(assembleDebug)) {  /* when run debug task */
        autoIncrementBuildNumber()
    } else if (taskGraph.hasTask(assembleRelease)) { /* when run release task */
        autoIncrementBuildNumber()
    }
}

Auto Increment Method Definition

 /*Wrapping inside a method avoids auto incrementing on every gradle task run. Now it runs only when we build apk*/
ext.autoIncrementBuildNumber = {

    if (versionPropsFile.canRead()) {
        def Properties versionProps = new Properties()
        versionProps.load(new FileInputStream(versionPropsFile))
        versionBuild = versionProps['VERSION_BUILD'].toInteger() + 1
        versionProps['VERSION_BUILD'] = versionBuild.toString()
        versionProps.store(versionPropsFile.newWriter(), null)
    } else {
        throw new GradleException("Could not read version.properties!")
    }
}

Read and Assign Version Number from a property file to a variable

def versionPropsFile = file(‘version.properties’) def versionBuild

/*Setting default value for versionBuild which is the last incremented value stored in the file */
if (versionPropsFile.canRead()) {
    def Properties versionProps = new Properties()
    versionProps.load(new FileInputStream(versionPropsFile))
    versionBuild = versionProps['VERSION_BUILD'].toInteger()
} else {
    throw new GradleException("Could not read version.properties!")
}