Gradle generates Querydsl metadata twice via different annotation processors

Question

I have a gradle build script. I want said script to generate QueryDSL-Metadata. Those metadata should be generated under the build/generated-sources/metamodel Folder.

The problem I am facing at the moment is that the metamodel is not only being generated once, but twice. Along with the desired target it is also being generated in the "default" buld/classes/... resulting in a "duplicate class"-error.

sourceSets {
    generated.java.srcDirs=['build/generated-sources/metamodel']
    main {
        java { srcDir 'src/main/java' }
    }
    test {
        java { srcDir 'src/main/test' }
    }
}

configurations { querydslapt }

dependencies {
    compile 'org.hibernate:hibernate-entitymanager:5.2.3.Final',
            'org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final-redhat-1',
            'com.querydsl:querydsl-jpa:4.1.3',
            // ... others, non-hibernate/querydsl ...
    querydslapt 'com.querydsl:querydsl-apt:4.1.3'
}

task generateSources(type: JavaCompile, group: 'build', description:'Generates the QueryDSL query types') {
    source = sourceSets.main.java
    classpath = configurations.compile + configurations.querydslapt
    options.compilerArgs = ['-proc:only',
                            '-processor', 'com.querydsl.apt.hibernate.HibernateAnnotationProcessor']
    destinationDir = sourceSets.generated.java.srcDirs.iterator().next()
}

compileJava {
    dependsOn generateSources
    source generateSources.destinationDir
}

According to the gradle trace, the Problem appears to be that there are two AnnotatioProcessors in the mix. First, the HibernateAnnotationProcessor. Second, a JPAAnnotationProcessor, eventually generating the duplicate class. And I can't figure out why, the build script looks ok-ish. I know, it might be guesswork, but I am grateful for any suggestions. I even cleaned my gradle-cache, just in case. It might not even be a pure build-script related issue, but the behavior persists even if I run the script via console.

Gist, basically exactly what I "should" need

(older) Post regarding this issue

Answer 1

This thread's solution works for me, the idea is to hook the Annotation Processor into the javac , the HibernateAnnotationProcessor can be declared via compilerArgs , roughly like:

dependencies {
    compile 'org.hibernate:hibernate-entitymanager:5.2.3.Final',
            'org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final-redhat-1',          
            'com.querydsl:querydsl-jpa:4.1.4',
            'com.querydsl:querydsl-apt:4.1.4',
            // other
}

ext {
    generatedSourcesDir = file("build/generated-sources/metamodel")
}

sourceSets {
    main {
        java {
            srcDir 'src/main/java'
            srcDir generatedSourcesDir
        }
    }
    test {
        java { srcDir 'src/main/test' }
    }
}

compileJava {
    doFirst {
        generatedSourcesDir.mkdirs()
    }
    options.compilerArgs += ['-s', generatedSourcesDir,
                             '-processor', 'com.querydsl.apt.hibernate.HibernateAnnotationProcessor']
}

But I still wonder why the first approach does not work (runs two annotation processors), so any idea is still highly appreciated.