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Groovy example source code file (

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

Java - Groovy tags/keywords

classadapter, classreader, compilationunit, genericstester, genericstester, groovyclassloader, groovytestcase, hashmap, mycollector, mycollector, myloader, myloader, string, string, util

The Groovy source code

 * Copyright 2003-2009 the original author or authors.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.
package gls.generics;

import groovy.lang.GroovyClassLoader;
import groovy.lang.GroovyClassLoader.InnerLoader;
import groovy.util.GroovyTestCase;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.control.CompilationFailedException;
import org.codehaus.groovy.control.CompilationUnit;
import org.codehaus.groovy.control.SourceUnit;
import org.objectweb.asm.*;

import java.util.HashMap;
import java.util.Map;

public class GenericsTestBase extends GroovyTestCase {
    MyLoader loader;
    HashMap signatures = new HashMap();
    private class MyLoader extends GroovyClassLoader{
        public MyLoader(ClassLoader classLoader) {

        protected ClassCollector createCollector(CompilationUnit unit,SourceUnit su) {
            return new MyCollector(new InnerLoader(this), unit, su);
    private class MyCollector extends GroovyClassLoader.ClassCollector{

        public MyCollector(InnerLoader myLoader, CompilationUnit unit, SourceUnit su) {
        protected Class createClass(byte[] code, ClassNode classNode) {
            ClassReader cr = new ClassReader(code);
            GenericsTester classVisitor = new GenericsTester(new org.objectweb.asm.tree.ClassNode());
            cr.accept(classVisitor, ClassWriter.COMPUTE_MAXS);
            return super.createClass(code,classNode);
    private class GenericsTester  extends ClassAdapter {
        public GenericsTester(ClassVisitor cv) {
        public void visit(int version, int access, String name,
                String signature, String superName, String[] interfaces) {
            if (signature!=null) signatures.put("class", signature);
        public FieldVisitor visitField(int access, String name, String desc,
                String signature, Object value) {
            if (signature!=null) signatures.put(name,signature);
            return super.visitField(access, name, desc, signature, value);
        public MethodVisitor visitMethod(int access, String name, String desc,
                String signature, String[] exceptions) {
            if (signature!=null) signatures.put(name+desc,signature);
            return super.visitMethod(access, name, desc, signature, exceptions);

    public void setUp(){
        loader = new MyLoader(this.getClass().getClassLoader());
    public void createClassInfo(String script) {
    public Map getSignatures() {
        return signatures;
    protected void shouldNotCompile(String script) {
        try {
        } catch (CompilationFailedException cfe) {
        throw new AssertionError("compilation of script '"+script+"' should have failed, but did not.");

Other Groovy examples (source code examples)

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