Android Studio don't generate R.java for my import project

Question

I import a project to Android Studio , but the R.java is always empty.

public final class R {
}

I have tried:

1. Make project,ma

Answer 1

I found my solution here. In short make sure not only the Eclipse plugin(if you are using eclipse) is updated. Also ensure that the Android SDK Tools, the SDK platform-tools and the SDK Build-tools are updated. After this restart your machine.

Answer 2

Best Solution for android studio Users :

Goto : Menu tab - > Build - > Rebuild Project

after rebuild Proj. your R.Java file problem will be solve automatically ..

Answer 3

So, this is the latest solution if anyone get's stuck like I did today especially, for R.Java file.

If you have lost the count of:

• Clean Project
• Rebuild Project
• Invalidate Caches / Restart
• deleted .gradle folder
• deleted .idea folder
• deleted app/build/generated folder
• checked your xml files
• checked your drawables and strings

then try this:

check your classpath dependency in your Project Gradle Scripts and if it's, this:

classpath 'com.android.tools.build:gradle:3.3.2'

then downgrade it to, this:

classpath 'com.android.tools.build:gradle:3.2.1'

Answer 4

I failed even if I tried to update the SDK tools as mentioned here.

Here is how I solved the problem (for the library projects imported).

In File -> Project Structure -> Modules, I removed the problematic projects, and added them again by selecting New Module -> Android Library Module.

After rebuilding the project, I got all the R.java files back.

Answer 5

I had a similar problem within my project using Android Studio 1.5.1. For me, bulding the project from command line by using following command resolved the problem:

gradle assembleRelease