/* * Copyright (c) 2023, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * @test * @bug 8301721 * @library /test/lib * @run main FindSpecialObjectMethod * @summary Test findSpecial on Object methods calling from a class or interface. */ import java.lang.invoke.MethodHandle; import java.lang.invoke.MethodHandles; import java.util.Objects; import static java.lang.invoke.MethodType.*; import static jdk.test.lib.Asserts.*; public class FindSpecialObjectMethod { static class C { public static Object test(C o) throws Throwable { MethodHandles.Lookup lookup = MethodHandles.lookup(); MethodHandle mh = lookup.findSpecial(Object.class, "toString", methodType(String.class), C.class); return mh.invoke(o); } public String toString() { return "C"; } } interface I { static Object test(I o) throws Throwable { MethodHandles.Lookup lookup = MethodHandles.lookup(); MethodHandle mh = lookup.findSpecial(Object.class, "toString", methodType(String.class), I.class); return mh.invoke(o); } static void noAccess() throws Throwable { try { MethodHandles.Lookup lookup = MethodHandles.lookup(); MethodHandle mh = lookup.findSpecial(String.class, "hashCode", methodType(int.class), I.class); throw new RuntimeException("IllegalAccessException not thrown"); } catch (IllegalAccessException ex) {} } } public static void main(String... args) throws Throwable { // Object.toString can be called from invokespecial from within // a special caller class C or interface I C c = new C(); I i = new I() {}; assertEquals(C.test(c), Objects.toIdentityString(c)); assertEquals(I.test(i), Objects.toIdentityString(i)); // I has no access to methods in other class besides Object I.noAccess(); } }