Android Studio R.java

In Android Studio 1.1.0 the R.java file is under

Project/app/build/generated/source/r/debug/com.android.'projectname'/R.java

If you don't see the above collection of folders, clean and build the project first. It takes a few minutes and you'll see Gradle running at the bottom of the IDE.

In Android Studio 3.4 and above that the R.java file is under

Project/app/build/generated/not_namespaced_r_class_sources/debug/processDebugResourc/r/com/{app package name} / R. java