Groovy example source code file (CompiledAtASTTransformation.groovy)

This example Groovy source code file (CompiledAtASTTransformation.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

annotation, asttransformation, asttransformation, classnode, classnode, compiledatasttransformation, list, methodnode, methodnode, sourceunit, string, string

The Groovy CompiledAtASTTransformation.groovy source code

package transforms.global

import org.codehaus.groovy.ast.*
import org.codehaus.groovy.transform.*
import org.codehaus.groovy.control.*
import org.codehaus.groovy.ast.expr.*
import org.codehaus.groovy.ast.stmt.*
import java.lang.annotation.*
import org.codehaus.groovy.ast.builder.AstBuilder

/**
* This ASTTransformation adds a static getCompiledTime() : String method to every class.  
*
* @author Hamlet D'Arcy
*/ 
@GroovyASTTransformation(phase=CompilePhase.CONVERSION)
public class CompiledAtASTTransformation implements ASTTransformation {

    private final static compileTime = new Date().toString()

    public void visit(ASTNode[] astNodes, SourceUnit sourceUnit) {

        List classes = sourceUnit.ast?.classes
        classes?.each { ClassNode clazz ->
            clazz.addMethod(makeMethod())
        }
    }

    /**
    *  OpCodes should normally be referenced, but in a standalone example I don't want to have to include
    * the jar at compile time. 
    */ 
    MethodNode makeMethod() {
        def ast = new AstBuilder().buildFromSpec {
            method('getCompiledTime', /*OpCodes.ACC_PUBLIC*/1 | /*OpCodes.ACC_STATIC*/8, String) {
                parameters {}
                exceptions {}
                block { 
                    returnStatement {
                        constant(compileTime) 
                    }
                }
                annotations {}
            }
        }
        ast[0]
    }
}