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/*
* Copyright (c) 2024, 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.
*/
import java.io.Serializable;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.util.function.IntSupplier;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
/*
* @test
* @bug 8343064
* @summary Test about when lambda caller/target class is a hidden class
* @run junit LambdaHiddenCaller
*/
public class LambdaHiddenCaller {
static Hooks hiddenCaller;
@BeforeAll
static void setup() throws Throwable {
byte[] bytes;
try (var in = LambdaHiddenCaller.class.getResourceAsStream("HiddenHooks.class")) {
bytes = in.readAllBytes();
}
var hiddenClassLookup = MethodHandles.lookup().defineHiddenClass(bytes, true);
hiddenCaller = (Hooks) hiddenClassLookup.findConstructor(hiddenClassLookup.lookupClass(), MethodType.methodType(void.class))
.asType(MethodType.methodType(Hooks.class)).invokeExact();
}
@Test
void testStaticMethod() {
var is = hiddenCaller.callStaticMethodLambda();
assertEquals(42, is.getAsInt());
}
@Test
void testSerializableLambda() {
var is = hiddenCaller.callSerializableLambda();
assertEquals(42, is.getAsInt());
assertTrue(Serializable.class.isAssignableFrom(is.getClass()));
// We do not guarantee serialization functionalities yet
}
}
/**
* Hooks to call hidden class methods easily.
*/
interface Hooks {
IntSupplier callStaticMethodLambda();
IntSupplier callSerializableLambda();
}
class HiddenHooks implements Hooks {
private static int compute() {
return 42;
}
@Override
public IntSupplier callStaticMethodLambda() {
return HiddenHooks::compute;
}
@Override
public IntSupplier callSerializableLambda() {
return (IntSupplier & Serializable) HiddenHooks::compute;
}
}
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