Why doesn't my annotationProcessor configuration see the version in my Gradle Platform?-CodePudding

I'm using a Gradle Platform (specifically java-platform) to control my transitive dependencies. I have the following modules:

platform/build.gradle

plugins {
    id 'java-platform'
}
dependencies {
    constraints {
        api('foo:bar:123')
    }
}

app/build.gradle:

plugins {
    id 'com.android.application'
}

android {
    buildToolsVersion rootProject.buildToolsVersion
    compileSdkVersion rootProject.compileSdkVersion

    defaultConfig {
        maxSdkVersion rootProject.maxSdkVersion
        minSdkVersion rootProject.minSdkVersion
        targetSdkVersion rootProject.targetSdkVersion
        versionCode 1
        versionName '1.0'
    }
    
    compileOptions {
        sourceCompatibility rootProject.sourceCompatibility
        targetCompatibility rootProject.targetCompatibility
    }
}

dependencies {
    api(platform(project(':platform')))

    annotationProcessor('foo:bar')
}

But when I run ./gradlew :app:dependencies, gradle fails to find my annotationProcessor version:

debugAnnotationProcessorClasspath - Resolved configuration for annotation-processor for variant: debug
\--- foo:bar FAILED

If I specify the version explicitly, then everything works:

app/build.gradle:

plugins {
    id 'com.android.application'
}

android {
    buildToolsVersion rootProject.buildToolsVersion
    compileSdkVersion rootProject.compileSdkVersion

    defaultConfig {
        maxSdkVersion rootProject.maxSdkVersion
        minSdkVersion rootProject.minSdkVersion
        targetSdkVersion rootProject.targetSdkVersion
        versionCode 1
        versionName '1.0'
    }
    
    compileOptions {
        sourceCompatibility rootProject.sourceCompatibility
        targetCompatibility rootProject.targetCompatibility
    }
}

dependencies {    
    annotationProcessor('foo:bar:123')
}

And then I see the version in ./gradlew :app:dependencies:

debugAnnotationProcessorClasspath - Resolved configuration for annotation-processor for variant: debug
\--- foo:bar:123

CodePudding user response：

I have to specify a Gradle Platform for every configuration I want to use it with, so

annotationProcessor(platform(project(':platform')))

This gradle issue provided a clue: https://github.com/gradle/gradle/issues/8723

These module definitions worked:

platform/build.gradle

plugins {
    id 'java-platform'
}
dependencies {
    constraints {
        api('foo:bar:123')
    }
}

app/build.gradle:

plugins {
    id 'com.android.application'
}

android {
    buildToolsVersion rootProject.buildToolsVersion
    compileSdkVersion rootProject.compileSdkVersion

    defaultConfig {
        maxSdkVersion rootProject.maxSdkVersion
        minSdkVersion rootProject.minSdkVersion
        targetSdkVersion rootProject.targetSdkVersion
        versionCode 1
        versionName '1.0'
    }
    
    compileOptions {
        sourceCompatibility rootProject.sourceCompatibility
        targetCompatibility rootProject.targetCompatibility
    }
}

dependencies {
    annotationProcessor(platform(project(':platform')))

    annotationProcessor('foo:bar')
}

CodePudding user response：

The annotationProcessor configuration represents a different dependency graph from your application classpath. It's completely independent, because it's dependencies which are "compiler plugins". So dependencies declared as implementation ... will not be found on the annotationProcessor path, and they must not. There's nothing different for your platform dependency here, so it's not because you declare a platform dependency on implementation that it will magically appear on the annotationProcessor path: there's no reason to do this.

Long story short: you need to declare your platform as a dependency of annotationProcessor too. Note that in absolute, there's no reason why you'd use the same dependency versions for your compiler classpath (the annotationProcessor path) and your application classpath: an annotation processor you use may for example depend on a different Guava version than your app, so it's a good idea to keep the platforms separate.