Access sdk.dir value in build.gradle after project evaluation

Question

I have a custom task in my build.gradle file that does bytecode transformations on class files before getting dex'd that looks like this:

task droidcook(type: JavaExec) {     main 'org.tsg.android.asm.Main' }  afterEvaluate { project ->     android.applicationVariants.each { variant ->         variant.javaCompile.doLast {             project.tasks.droidcook.configure {                 classpath variant.javaCompile.classpath                 classpath "build/classes/" + variant.dirName                 classpath sdk.dir + "/platforms/android-19/android.jar"                 classpath "compile-libs/droidcook.jar"                 args "build/classes/" + variant.dirName                 args "com.example"                 // args "-debug"                 // args "-asmifier"             }             project.tasks.droidcook.execute()         }     } } 

The issue with the above is the classpath sdk.dir + ... line where sdk.dir isn't evaluated appropriately. To get this working, I currently have to hard code the path to the android.jar.

Bonus points if you can answer with an appropriate value to replace android-19 with for accessing a platform specific android.jar based on project configuration. :D

Answer 1

I don't see a published API to expose sdk.dir to your build file, so I just cribbed the code from https://android.googlesource.com/platform/tools/build/+/d69964104aed4cfae5052028b5c5e57580441ae8/gradle/src/main/groovy/com/android/build/gradle/internal/Sdk.groovy to read it manually. As for replacing android-19, if I read android.compileSdkVersion I get that exact string. I'm not sure that this is a published API either, so it may be subject to change and breakage in future versions of the Android Gradle plugin.

With that said, this works for me:

afterEvaluate {     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 androidJarPath = sdkDir + "/platforms/" + android.compileSdkVersion + "/android.jar"         print androidJarPath + "\n"     } } 

If there's no local.properties, this code is going to fail. If you care about that case, you can copy more code from Sdk.groovy to mimic its behavior in trying to find a reasonable default.