Gradle for Javadoc

library/build.gradle

@@ -54,6 +54,21 @@ android.libraryVariants.all { variant ->
     artifacts.add('archives', task);
 }
 
+android.libraryVariants.all { variant ->
+    task("generate${variant.name.capitalize()}Javadoc", type: Javadoc) {
+        title = "$name $version API"
+        description "Generates Javadoc for $variant.name."
+        source = variant.javaCompile.source
+        classpath = files(variant.javaCompile.classpath.files, project.android.getBootClasspath())
+        options {
+            links "http://docs.oracle.com/javase/7/docs/api/"
+            linksOffline "http://d.android.com/reference","${android.sdkDirectory}/docs/reference"
+        }
+        exclude '**/BuildConfig.java'
+        exclude '**/R.java'
+    }
+}
+
 publish {
     repoName = 'exoplayer'
     userOrg = 'google'