Gradle - Groovy and Java class dependency - Compile

Question

My project has both Java (N files) and Groovy code (1 file only). Java compile depends upon this single Groovy file\'s class file for Java compilation (compileJava task to s

Answer 1

The Groovy (base) plugin makes GroovyCompile tasks depend on the corresponding JavaCompile tasks because it's more common to call from Groovy into Java than the other way around. If you need it the other way around (or both ways), joint compilation is a good solution. Here is a somewhat improved (over your version) joint compilation setup:

sourceSets {
    main {
        groovy {
            // override the default locations, rather than adding additional ones
            srcDirs = ['src/groovy', 'src/java'] 
        }
        java {
            srcDirs = [] // don't compile Java code twice 
        }
    }
}

If you prefer separate compilation with Java->Groovy dependencies only, something like the following should work:

// since you aren't using the default locations
sourceSets {
    main {
        groovy {
            srcDirs = ['src/groovy']
        }
        java {
            srcDirs = ['src/java']
        }
    }
}

// remove GroovyCompile->JavaCompile task dependencies
tasks.withType(GroovyCompile) {
    dependsOn = [] 
}

// add JavaCompile->GroovyCompile task dependencies
tasks.withType(JavaCompile) { task ->  
    dependsOn task.name.replace("Java", "Groovy")
}

Because a JavaCompile task and its corresponding GroovyCompile task write to the same output directory, Java compilation will now have the compiled Groovy code on its compile class path.

PS: Calling a task from another task is not supported, and bad things can happen if you try. Instead, you should always work with task relationships (dependsOn, finalizedBy, mustRunAfter, shouldRunAfter).