/* * Copyright (c) 2009, 2011, 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. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * 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 * @summary example code used in javadoc for java.lang.invoke API * @compile -XDallowTransitionalJSR292=no JavaDocExamplesTest.java * @run junit/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableMethodHandles test.java.lang.invoke.JavaDocExamplesTest */ /* ---- To run outside jtreg: $ $JAVA7X_HOME/bin/javac -cp $JUNIT4_JAR -d /tmp/Classes \ $DAVINCI/sources/jdk/test/java/lang/invoke/JavaDocExamplesTest.java $ $JAVA7X_HOME/bin/java -cp $JUNIT4_JAR:/tmp/Classes \ -XX:+UnlockExperimentalVMOptions -XX:+EnableMethodHandles \ -Dtest.java.lang.invoke.JavaDocExamplesTest.verbosity=1 \ test.java.lang.invoke.JavaDocExamplesTest ---- */ package test.java.lang.invoke; import java.lang.invoke.*; import static java.lang.invoke.MethodHandles.*; import static java.lang.invoke.MethodType.*; import java.lang.reflect.*; import java.util.*; import org.junit.*; import static org.junit.Assert.*; import static org.junit.Assume.*; /** * @author jrose */ public class JavaDocExamplesTest { /** Wrapper for running the JUnit tests in this module. * Put JUnit on the classpath! */ public static void main(String... ignore) { org.junit.runner.JUnitCore.runClasses(JavaDocExamplesTest.class); } // How much output? static int verbosity = Integer.getInteger("test.java.lang.invoke.JavaDocExamplesTest.verbosity", 0); {} static final private Lookup LOOKUP = lookup(); // static final private MethodHandle CONCAT_1 = LOOKUP.findVirtual(String.class, // "concat", methodType(String.class, String.class)); // static final private MethodHandle HASHCODE_1 = LOOKUP.findVirtual(Object.class, // "hashCode", methodType(int.class)); // form required if ReflectiveOperationException is intercepted: static final private MethodHandle CONCAT_2, HASHCODE_2; static { try { CONCAT_2 = LOOKUP.findVirtual(String.class, "concat", methodType(String.class, String.class)); HASHCODE_2 = LOOKUP.findVirtual(Object.class, "hashCode", methodType(int.class)); } catch (ReflectiveOperationException ex) { throw new RuntimeException(ex); } } {} @Test public void testFindVirtual() throws Throwable { {} MethodHandle CONCAT_3 = LOOKUP.findVirtual(String.class, "concat", methodType(String.class, String.class)); MethodHandle HASHCODE_3 = LOOKUP.findVirtual(Object.class, "hashCode", methodType(int.class)); //assertEquals("xy", (String) CONCAT_1.invokeExact("x", "y")); assertEquals("xy", (String) CONCAT_2.invokeExact("x", "y")); assertEquals("xy", (String) CONCAT_3.invokeExact("x", "y")); //assertEquals("xy".hashCode(), (int) HASHCODE_1.invokeExact((Object)"xy")); assertEquals("xy".hashCode(), (int) HASHCODE_2.invokeExact((Object)"xy")); assertEquals("xy".hashCode(), (int) HASHCODE_3.invokeExact((Object)"xy")); {} } @Test public void testDropArguments() throws Throwable { {{ {} /// JAVADOC MethodHandle cat = lookup().findVirtual(String.class, "concat", methodType(String.class, String.class)); assertEquals("xy", (String) cat.invokeExact("x", "y")); MethodType bigType = cat.type().insertParameterTypes(0, int.class, String.class); MethodHandle d0 = dropArguments(cat, 0, bigType.parameterList().subList(0,2)); assertEquals(bigType, d0.type()); assertEquals("yz", (String) d0.invokeExact(123, "x", "y", "z")); }} {{ {} /// JAVADOC MethodHandle cat = lookup().findVirtual(String.class, "concat", methodType(String.class, String.class)); assertEquals("xy", (String) cat.invokeExact("x", "y")); MethodHandle d0 = dropArguments(cat, 0, String.class); assertEquals("yz", (String) d0.invokeExact("x", "y", "z")); MethodHandle d1 = dropArguments(cat, 1, String.class); assertEquals("xz", (String) d1.invokeExact("x", "y", "z")); MethodHandle d2 = dropArguments(cat, 2, String.class); assertEquals("xy", (String) d2.invokeExact("x", "y", "z")); MethodHandle d12 = dropArguments(cat, 1, int.class, boolean.class); assertEquals("xz", (String) d12.invokeExact("x", 12, true, "z")); }} } @Test public void testFilterArguments() throws Throwable { {{ {} /// JAVADOC MethodHandle cat = lookup().findVirtual(String.class, "concat", methodType(String.class, String.class)); MethodHandle upcase = lookup().findVirtual(String.class, "toUpperCase", methodType(String.class)); assertEquals("xy", (String) cat.invokeExact("x", "y")); MethodHandle f0 = filterArguments(cat, 0, upcase); assertEquals("Xy", (String) f0.invokeExact("x", "y")); // Xy MethodHandle f1 = filterArguments(cat, 1, upcase); assertEquals("xY", (String) f1.invokeExact("x", "y")); // xY MethodHandle f2 = filterArguments(cat, 0, upcase, upcase); assertEquals("XY", (String) f2.invokeExact("x", "y")); // XY }} } static void assertEquals(Object exp, Object act) { if (verbosity > 0) System.out.println("result: "+act); Assert.assertEquals(exp, act); } @Test public void testMethodHandlesSummary() throws Throwable { {{ {} /// JAVADOC Object x, y; String s; int i; MethodType mt; MethodHandle mh; MethodHandles.Lookup lookup = MethodHandles.lookup(); // mt is (char,char)String mt = MethodType.methodType(String.class, char.class, char.class); mh = lookup.findVirtual(String.class, "replace", mt); s = (String) mh.invokeExact("daddy",'d','n'); // invokeExact(Ljava/lang/String;CC)Ljava/lang/String; assert(s.equals("nanny")); // weakly typed invocation (using MHs.invoke) s = (String) mh.invokeWithArguments("sappy", 'p', 'v'); assert(s.equals("savvy")); // mt is (Object[])List mt = MethodType.methodType(java.util.List.class, Object[].class); mh = lookup.findStatic(java.util.Arrays.class, "asList", mt); assert(mh.isVarargsCollector()); x = mh.invokeGeneric("one", "two"); // invokeGeneric(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object; assert(x.equals(java.util.Arrays.asList("one","two"))); // mt is (Object,Object,Object)Object mt = MethodType.genericMethodType(3); mh = mh.asType(mt); x = mh.invokeExact((Object)1, (Object)2, (Object)3); // invokeExact(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object; assert(x.equals(java.util.Arrays.asList(1,2,3))); // mt is { => int} mt = MethodType.methodType(int.class); mh = lookup.findVirtual(java.util.List.class, "size", mt); i = (int) mh.invokeExact(java.util.Arrays.asList(1,2,3)); // invokeExact(Ljava/util/List;)I assert(i == 3); mt = MethodType.methodType(void.class, String.class); mh = lookup.findVirtual(java.io.PrintStream.class, "println", mt); mh.invokeExact(System.out, "Hello, world."); // invokeExact(Ljava/io/PrintStream;Ljava/lang/String;)V {} }} } @Test public void testAsVarargsCollector() throws Throwable { {{ {} /// JAVADOC MethodHandle asList = publicLookup() .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class)) .asVarargsCollector(Object[].class); assertEquals("[]", asList.invokeGeneric().toString()); assertEquals("[1]", asList.invokeGeneric(1).toString()); assertEquals("[two, too]", asList.invokeGeneric("two", "too").toString()); Object[] argv = { "three", "thee", "tee" }; assertEquals("[three, thee, tee]", asList.invokeGeneric(argv).toString()); List ls = (List) asList.invokeGeneric((Object)argv); assertEquals(1, ls.size()); assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0))); }} } @Test public void testVarargsCollectorSuppression() throws Throwable { {{ {} /// JAVADOC MethodHandle vamh = publicLookup() .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class)) .asVarargsCollector(Object[].class); MethodHandle mh = MethodHandles.exactInvoker(vamh.type()).bindTo(vamh); assert(vamh.type().equals(mh.type())); assertEquals("[1, 2, 3]", vamh.invokeGeneric(1,2,3).toString()); boolean failed = false; try { mh.invokeGeneric(1,2,3); } catch (WrongMethodTypeException ex) { failed = true; } assert(failed); {} }} } }