russell@unturf.com
0a580b313d
Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com Patches, unit tests, benchmarks, whitepaper, and outreach briefs. Public domain — no copyright claimed. Use freely.
86 lines
3.5 KiB
Java
86 lines
3.5 KiB
Java
/*
|
|
* Copyright (c) 2025, 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.lang.reflect.Method;
|
|
import java.lang.reflect.Proxy;
|
|
import java.lang.reflect.UndeclaredThrowableException;
|
|
import java.util.ArrayList;
|
|
import java.util.List;
|
|
import java.util.concurrent.Callable;
|
|
import java.util.function.Consumer;
|
|
|
|
import org.junit.jupiter.api.Test;
|
|
|
|
import static org.junit.jupiter.api.Assertions.*;
|
|
|
|
/*
|
|
* @test
|
|
* @bug 8370839
|
|
* @summary Behavior of bridge methods in interfaces
|
|
* @run junit BridgeMethodsTest
|
|
*/
|
|
public class BridgeMethodsTest {
|
|
|
|
interface StringCallable extends Callable<String> {
|
|
@Override
|
|
String call(); // throws no exception
|
|
}
|
|
|
|
@Test
|
|
void testExceptionTypes() throws Throwable {
|
|
class MyException extends Exception {}
|
|
// This proxy has two distinct methods, even though the
|
|
// Java language would treat the first one as overridden:
|
|
// Object call() throws Exception; - from Callable
|
|
// String call(); - from StringCallable
|
|
var instance = Proxy.newProxyInstance(StringCallable.class.getClassLoader(),
|
|
new Class[] { StringCallable.class }, (_, _, _) -> { throw new MyException(); });
|
|
// The exception can't be thrown through StringCallable.call which has no throws
|
|
var undeclared = assertThrows(UndeclaredThrowableException.class, () -> ((StringCallable) instance).call());
|
|
assertInstanceOf(MyException.class, undeclared.getCause());
|
|
// But it can be thrown through Callable.call which permits Exception
|
|
assertThrows(MyException.class, () -> ((Callable<?>) instance).call());
|
|
}
|
|
|
|
interface SpecificConsumer extends Consumer<String> {
|
|
@Override
|
|
void accept(String s);
|
|
}
|
|
|
|
@Test
|
|
@SuppressWarnings("unchecked")
|
|
void testMethodObjects() throws Throwable {
|
|
List<Method> methods = new ArrayList<>();
|
|
// This proxy has two distinct methods, even though the
|
|
// Java language would treat the first one as overridden:
|
|
// void accept(Object); - from Consumer
|
|
// void accept(String); - from SpecificConsumer
|
|
var instance = Proxy.newProxyInstance(SpecificConsumer.class.getClassLoader(),
|
|
new Class[] { SpecificConsumer.class }, (_, m, _) -> methods.add(m));
|
|
((Consumer<Object>) instance).accept(null);
|
|
((SpecificConsumer) instance).accept(null);
|
|
assertEquals(2, methods.size());
|
|
// invocation handler gets different method due to covariant parameter types
|
|
assertNotEquals(methods.getFirst(), methods.getLast());
|
|
}
|
|
}
|