overridesspecex.java

来自「是一款用JAVA 编写的编译器 具有很强的编译功能」· Java 代码 · 共 124 行

/*
 * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

/*
 * @test
 * @bug     6453386
 * @summary Verify that example code in Elements.overrides works as spec'ed.
 * @author  Scott Seligman
 * @compile -g OverridesSpecEx.java
 * @compile -processor OverridesSpecEx -proc:only OverridesSpecEx.java
 */

import java.util.Set;
import javax.annotation.processing.*;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.*;
import javax.lang.model.type.*;
import javax.lang.model.util.*;

import static javax.lang.model.util.ElementFilter.*;


@SupportedSourceVersion(SourceVersion.RELEASE_6)
@SupportedAnnotationTypes("*")
public class OverridesSpecEx extends AbstractProcessor {

    Elements elements;
    Types types;

    public void init(ProcessingEnvironment penv) {
	super.init(penv);
	elements = penv.getElementUtils();
	types =  penv.getTypeUtils();
    }

    public boolean process(Set<? extends TypeElement> annoTypes,
			   RoundEnvironment round) {
	if (!round.processingOver())
	    doit(annoTypes, round);
	return true;
    }

    private void doit(Set<? extends TypeElement> annoTypes,
		      RoundEnvironment round) {
	TypeElement string = elements.getTypeElement("java.lang.String");
	TypeElement object = elements.getTypeElement("java.lang.Object");

	ExecutableElement m1 = null;
	ExecutableElement m2 = null;
	for (ExecutableElement m : methodsIn(string.getEnclosedElements())) {
	    if (m.getSimpleName().contentEquals("hashCode")) {
		m1 = m;
		break;
	    }
	}
	for (ExecutableElement m : methodsIn(object.getEnclosedElements())) {
	    if (m.getSimpleName().contentEquals("hashCode")) {
		m2 = m;
		break;
	    }
	}

	boolean res =
	    elements.overrides(m1, m2, (TypeElement) m1.getEnclosingElement());
	System.out.println("String.hashCode overrides Object.hashCode?  " + res);
	checkResult(res);

	TypeElement a = elements.getTypeElement("OverridesSpecEx.A");
	TypeElement b = elements.getTypeElement("OverridesSpecEx.B");
	TypeElement c = elements.getTypeElement("OverridesSpecEx.C");

	m1 = null;
	m2 = null;
	for (ExecutableElement m : methodsIn(a.getEnclosedElements()))
	    m1 = m;
	for (ExecutableElement m : methodsIn(b.getEnclosedElements()))
	    m2 = m;

	res = elements.overrides(m1, m2, a);
	System.out.println("A.m overrides B.m in B?  " + res);
	checkResult(!res);
	res = elements.overrides(m1, m2, c);
	System.out.println("A.m overrides B.m in C?  " + res);
	checkResult(res);
    }

    private static void checkResult(boolean truthiness) {
	if (!truthiness)
	    throw new AssertionError("Bogus result");
    }


    // Fodder for the processor

    class A {
	public void m() {}
    }
    interface B {
	void m();
    }
    class C extends A implements B {
    }
}