Gradle deprecated annotation processor warnings for lombok

Question

After upgrading to gradle 4.7, my previously warning-free build now emits this warning:

The following annotation processors were detected on the compile classpath: 'lombok.launch.AnnotationProcessorHider$AnnotationProcessor' and 'lombok.launch.AnnotationProcessorHider$ClaimingProcessor'. Detecting annotation processors on the compile classpath is deprecated and Gradle 5.0 will ignore them. Please add them to the annotation processor path instead. If you did not intend to use annotation processors, you can use the '-proc:none' compiler argument to ignore them.

It seems that annotation processors are deprecated and gradle version 5.0 will not support annotation processors.

My project uses lombok, which requries annotation processors, so using -proc:none is not an option. Neither is stopping using Gradle when verison 5.0 is released.

How do I:

• stop the warnings, and
• ensure my project will continue to build with future Gradle releases?

Answer 1

Change the lombok dependency type from compile to annotationProcessor, so your dependencies section in your build.gradle file should look like:

dependencies {
    compileOnly('org.projectlombok:lombok:1.16.20')
    annotationProcessor 'org.projectlombok:lombok:1.16.20'
    // compile 'org.projectlombok:lombok:1.16.20' <-- this no longer works!
    // other dependencies...
}

Answer 2

If your project contains tests then you'll need the following configuration to completely rid yourself of the gradle warning:

dependencies {
  compileOnly "org.projectlombok:lombok:1.18.2"
  testCompileOnly "org.projectlombok:lombok:1.18.2"
  annotationProcessor "org.projectlombok:lombok:1.18.2"
  testAnnotationProcessor "org.projectlombok:lombok:1.18.2"
}

Adjust the lombok version to suit.

Answer 3

Gradle added annotationProcessor in 4.6 and Lombok is an annotation processor even though their documentation is not really clear about this when using Gradle they are also aware of it as they recommend it when using Android Studio. So short answer is to use:

dependencies {
    compileOnly('org.projectlombok:lombok:1.18.0')
    annotationProcessor('org.projectlombok:lombok:1.18.0')
}