Major-Minor-Patch-Build gradle

import java.util.regex.Pattern

task('increaseVersionCode') << {
    def manifestFile = file("src/main/AndroidManifest.xml")
    def pattern = Pattern.compile("versionCode=\"(\\d+)\"")
    def manifestText = manifestFile.getText()
    def matcher = pattern.matcher(manifestText)
    matcher.find()
    def versionCode = Integer.parseInt(matcher.group(1))
    def manifestContent = matcher.replaceAll("versionCode=\"" + ++versionCode + "\"")
    manifestFile.write(manifestContent)
}

task('incrementVersionName') << {
    def manifestFile = file("src/main/AndroidManifest.xml")
    def patternVersionNumber = Pattern.compile("versionName=\"(\\d+)\\.(\\d+)\\.(\\d+)\\.(\\d+)\"")
    def manifestText = manifestFile.getText()
    def matcherVersionNumber = patternVersionNumber.matcher(manifestText)
    matcherVersionNumber.find()
    def majorVersion = Integer.parseInt(matcherVersionNumber.group(1))
    def minorVersion = Integer.parseInt(matcherVersionNumber.group(2))
    def pointVersion = Integer.parseInt(matcherVersionNumber.group(3))
    def buildVersion = Integer.parseInt(matcherVersionNumber.group(4))
    def mNextVersionName = majorVersion + "." + minorVersion + "." + pointVersion + "." + (buildVersion + 1)
    def manifestContent = matcherVersionNumber.replaceAll("versionName=\"" + mNextVersionName + "\"")
    manifestFile.write(manifestContent)
}

tasks.whenTaskAdded { task ->
    if (task.name == 'generateReleaseBuildConfig' || task.name == 'generateDebugBuildConfig') {
        task.dependsOn 'increaseVersionCode'
        task.dependsOn 'incrementVersionName'
    }

http://stackoverflow.com/a/21951328/4142087