| /* |
| * Copyright (c) 2015, 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 8020968 |
| * @summary Sanity test for Function wildcard signature |
| * @run main WalkFunction |
| */ |
| |
| import java.lang.StackWalker.StackFrame; |
| import java.util.Optional; |
| import java.util.function.Function; |
| import java.util.stream.Stream; |
| |
| public class WalkFunction { |
| private static final StackWalker walker = StackWalker.getInstance(); |
| |
| public static void main(String... args) throws Exception { |
| testFunctions(); |
| testWildcards(); |
| walker.walk(counter()); |
| walker.walk(wildCounter()); |
| } |
| |
| private static void testFunctions() { |
| walker.walk(Stream::count); |
| |
| try { |
| walker.walk(null); |
| throw new RuntimeException("NPE expected"); |
| } catch (NullPointerException e) {} |
| |
| Optional<StackFrame> result = walker.walk(WalkFunction::reduce); |
| if (!result.get().getClassName().equals(WalkFunction.class.getName())) { |
| throw new RuntimeException(result.get() + " expected: " + WalkFunction.class.getName()); |
| } |
| } |
| |
| static Optional<StackFrame> reduce(Stream<StackFrame> stream) { |
| return stream.reduce((r,f) -> r.getClassName().compareTo(f.getClassName()) > 0 ? f : r); |
| } |
| |
| private static void testWildcards() { |
| Function<? super Stream<? extends StackFrame>, Void> f1 = WalkFunction::function; |
| Function<? super Stream<? super StackFrame>, Void> f2 = WalkFunction::function; |
| Function<? super Stream<StackFrame>, Void> f3 = WalkFunction::function; |
| Function<Stream<? extends StackFrame>, Void> f4 = WalkFunction::function; |
| Function<Stream<? super StackFrame>, Void> f5 = WalkFunction::function; |
| Function<Stream<StackFrame>, Void> f6 = WalkFunction::function; |
| walker.walk(f1); |
| walker.walk(f2); |
| walker.walk(f3); |
| walker.walk(f4); |
| walker.walk(f5); |
| walker.walk(f6); |
| } |
| |
| private static Void function(Stream<?> s) { |
| return null; |
| } |
| |
| private static Function<Stream<?>, Long> wildCounter() { |
| return Stream::count; |
| } |
| private static <T> Function<Stream<T>, Long> counter() { |
| return Stream::count; |
| } |
| } |