3011N/A/*
3528N/A * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
3011N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3011N/A *
3011N/A * This code is free software; you can redistribute it and/or modify it
3011N/A * under the terms of the GNU General Public License version 2 only, as
3011N/A * published by the Free Software Foundation. Oracle designates this
3011N/A * particular file as subject to the "Classpath" exception as provided
3011N/A * by Oracle in the LICENSE file that accompanied this code.
3011N/A *
3011N/A * This code is distributed in the hope that it will be useful, but WITHOUT
3011N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
3011N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
3011N/A * version 2 for more details (a copy is included in the LICENSE file that
3011N/A * accompanied this code).
3011N/A *
3011N/A * You should have received a copy of the GNU General Public License version
3011N/A * 2 along with this work; if not, write to the Free Software Foundation,
3011N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
3011N/A *
3011N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
3011N/A * or visit www.oracle.com if you need additional information or have any
3011N/A * questions.
3011N/A */
3011N/A
3011N/A/* @test
3793N/A * @summary example code used in javadoc for java.lang.invoke API
3907N/A * @compile JavaDocExamplesTest.java
3907N/A * @run junit/othervm test.java.lang.invoke.JavaDocExamplesTest
3011N/A */
3011N/A
3011N/A/*
3011N/A---- To run outside jtreg:
3011N/A$ $JAVA7X_HOME/bin/javac -cp $JUNIT4_JAR -d /tmp/Classes \
3793N/A $DAVINCI/sources/jdk/test/java/lang/invoke/JavaDocExamplesTest.java
3011N/A$ $JAVA7X_HOME/bin/java -cp $JUNIT4_JAR:/tmp/Classes \
4250N/A -DJavaDocExamplesTest.verbosity=1 \
3793N/A test.java.lang.invoke.JavaDocExamplesTest
3011N/A----
3011N/A*/
3011N/A
3793N/Apackage test.java.lang.invoke;
3011N/A
3793N/Aimport java.lang.invoke.*;
3793N/Aimport static java.lang.invoke.MethodHandles.*;
3793N/Aimport static java.lang.invoke.MethodType.*;
3011N/A
3011N/Aimport java.util.*;
3011N/A
3011N/Aimport org.junit.*;
3011N/Aimport static org.junit.Assert.*;
3011N/A
3011N/A
3011N/A/**
3011N/A * @author jrose
3011N/A */
3240N/Apublic class JavaDocExamplesTest {
3011N/A /** Wrapper for running the JUnit tests in this module.
3011N/A * Put JUnit on the classpath!
3011N/A */
4250N/A public static void main(String... ignore) throws Throwable {
4250N/A System.out.println("can run this as:");
4250N/A System.out.println("$ java org.junit.runner.JUnitCore "+JavaDocExamplesTest.class.getName());
4250N/A new JavaDocExamplesTest().run();
4250N/A }
4250N/A public void run() throws Throwable {
4250N/A testFindVirtual();
4250N/A testPermuteArguments();
4250N/A testDropArguments();
4250N/A testFilterArguments();
4250N/A testFoldArguments();
5452N/A testFoldArguments2();
4250N/A testMethodHandlesSummary();
4250N/A testAsSpreader();
4250N/A testAsCollector();
4250N/A testAsVarargsCollector();
4250N/A testAsFixedArity();
4250N/A testAsTypeCornerCases();
4250N/A testMutableCallSite();
3011N/A }
3011N/A // How much output?
4250N/A static final Class<?> THIS_CLASS = JavaDocExamplesTest.class;
4250N/A static int verbosity = Integer.getInteger(THIS_CLASS.getSimpleName()+".verbosity", 0);
4250N/A
3011N/A
3011N/A{}
3011N/Astatic final private Lookup LOOKUP = lookup();
3011N/A// static final private MethodHandle CONCAT_1 = LOOKUP.findVirtual(String.class,
3011N/A// "concat", methodType(String.class, String.class));
3011N/A// static final private MethodHandle HASHCODE_1 = LOOKUP.findVirtual(Object.class,
3011N/A// "hashCode", methodType(int.class));
3011N/A
3530N/A// form required if ReflectiveOperationException is intercepted:
4250N/A static final private MethodHandle CONCAT_2, HASHCODE_2, ADD_2, SUB_2;
3011N/Astatic {
3011N/A try {
4250N/A Class<?> THIS_CLASS = LOOKUP.lookupClass();
3011N/A CONCAT_2 = LOOKUP.findVirtual(String.class,
3011N/A "concat", methodType(String.class, String.class));
3011N/A HASHCODE_2 = LOOKUP.findVirtual(Object.class,
3011N/A "hashCode", methodType(int.class));
4250N/A ADD_2 = LOOKUP.findStatic(THIS_CLASS, "add", methodType(int.class, int.class, int.class));
4250N/A SUB_2 = LOOKUP.findStatic(THIS_CLASS, "sub", methodType(int.class, int.class, int.class));
3530N/A } catch (ReflectiveOperationException ex) {
3011N/A throw new RuntimeException(ex);
3011N/A }
3011N/A}
4250N/A static int add(int x, int y) { return x + y; }
4250N/A static int sub(int x, int y) { return x - y; }
4250N/A
3011N/A{}
3011N/A
3011N/A @Test public void testFindVirtual() throws Throwable {
3011N/A{}
3011N/AMethodHandle CONCAT_3 = LOOKUP.findVirtual(String.class,
3011N/A "concat", methodType(String.class, String.class));
3011N/AMethodHandle HASHCODE_3 = LOOKUP.findVirtual(Object.class,
3011N/A "hashCode", methodType(int.class));
3011N/A//assertEquals("xy", (String) CONCAT_1.invokeExact("x", "y"));
3241N/AassertEquals("xy", (String) CONCAT_2.invokeExact("x", "y"));
3241N/AassertEquals("xy", (String) CONCAT_3.invokeExact("x", "y"));
3241N/A//assertEquals("xy".hashCode(), (int) HASHCODE_1.invokeExact((Object)"xy"));
3241N/AassertEquals("xy".hashCode(), (int) HASHCODE_2.invokeExact((Object)"xy"));
3241N/AassertEquals("xy".hashCode(), (int) HASHCODE_3.invokeExact((Object)"xy"));
3011N/A{}
3011N/A }
4250N/A
4250N/A @Test public void testPermuteArguments() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodType intfn1 = methodType(int.class, int.class);
4250N/AMethodType intfn2 = methodType(int.class, int.class, int.class);
4250N/AMethodHandle sub = SUB_2;// ... {int x, int y => x-y} ...;
4250N/Aassert(sub.type().equals(intfn2));
4250N/AMethodHandle sub1 = permuteArguments(sub, intfn2, 0, 1);
4250N/AMethodHandle rsub = permuteArguments(sub, intfn2, 1, 0);
4250N/Aassert((int)rsub.invokeExact(1, 100) == 99);
4250N/AMethodHandle add = ADD_2;// ... {int x, int y => x+y} ...;
4250N/Aassert(add.type().equals(intfn2));
4250N/AMethodHandle twice = permuteArguments(add, intfn1, 0, 0);
4250N/Aassert(twice.type().equals(intfn1));
4250N/Aassert((int)twice.invokeExact(21) == 42);
4250N/A }}
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodHandle cat = lookup().findVirtual(String.class,
4250N/A "concat", methodType(String.class, String.class));
4250N/AassertEquals("xy", (String) cat.invokeExact("x", "y"));
4250N/AMethodHandle d0 = dropArguments(cat, 0, String.class);
4250N/AassertEquals("yz", (String) d0.invokeExact("x", "y", "z"));
4250N/AMethodHandle d1 = dropArguments(cat, 1, String.class);
4250N/AassertEquals("xz", (String) d1.invokeExact("x", "y", "z"));
4250N/AMethodHandle d2 = dropArguments(cat, 2, String.class);
4250N/AassertEquals("xy", (String) d2.invokeExact("x", "y", "z"));
4250N/AMethodHandle d12 = dropArguments(cat, 1, int.class, boolean.class);
4250N/AassertEquals("xz", (String) d12.invokeExact("x", 12, true, "z"));
4250N/A }}
4250N/A }
4250N/A
3011N/A @Test public void testDropArguments() throws Throwable {
3011N/A {{
3011N/A{} /// JAVADOC
3011N/AMethodHandle cat = lookup().findVirtual(String.class,
3011N/A "concat", methodType(String.class, String.class));
3247N/AassertEquals("xy", (String) cat.invokeExact("x", "y"));
3793N/AMethodType bigType = cat.type().insertParameterTypes(0, int.class, String.class);
3793N/AMethodHandle d0 = dropArguments(cat, 0, bigType.parameterList().subList(0,2));
3793N/AassertEquals(bigType, d0.type());
3793N/AassertEquals("yz", (String) d0.invokeExact(123, "x", "y", "z"));
3793N/A }}
3793N/A {{
3793N/A{} /// JAVADOC
3793N/AMethodHandle cat = lookup().findVirtual(String.class,
3793N/A "concat", methodType(String.class, String.class));
3793N/AassertEquals("xy", (String) cat.invokeExact("x", "y"));
3011N/AMethodHandle d0 = dropArguments(cat, 0, String.class);
3247N/AassertEquals("yz", (String) d0.invokeExact("x", "y", "z"));
3011N/AMethodHandle d1 = dropArguments(cat, 1, String.class);
3247N/AassertEquals("xz", (String) d1.invokeExact("x", "y", "z"));
3011N/AMethodHandle d2 = dropArguments(cat, 2, String.class);
3247N/AassertEquals("xy", (String) d2.invokeExact("x", "y", "z"));
3011N/AMethodHandle d12 = dropArguments(cat, 1, int.class, boolean.class);
3247N/AassertEquals("xz", (String) d12.invokeExact("x", 12, true, "z"));
3011N/A }}
3011N/A }
3011N/A
3240N/A @Test public void testFilterArguments() throws Throwable {
3240N/A {{
3240N/A{} /// JAVADOC
3240N/AMethodHandle cat = lookup().findVirtual(String.class,
3240N/A "concat", methodType(String.class, String.class));
3240N/AMethodHandle upcase = lookup().findVirtual(String.class,
3240N/A "toUpperCase", methodType(String.class));
3247N/AassertEquals("xy", (String) cat.invokeExact("x", "y"));
3240N/AMethodHandle f0 = filterArguments(cat, 0, upcase);
3247N/AassertEquals("Xy", (String) f0.invokeExact("x", "y")); // Xy
3240N/AMethodHandle f1 = filterArguments(cat, 1, upcase);
3247N/AassertEquals("xY", (String) f1.invokeExact("x", "y")); // xY
3240N/AMethodHandle f2 = filterArguments(cat, 0, upcase, upcase);
3247N/AassertEquals("XY", (String) f2.invokeExact("x", "y")); // XY
3240N/A }}
3240N/A }
3240N/A
4250N/A @Test public void testFoldArguments() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodHandle trace = publicLookup().findVirtual(java.io.PrintStream.class,
4250N/A "println", methodType(void.class, String.class))
4250N/A .bindTo(System.out);
4250N/AMethodHandle cat = lookup().findVirtual(String.class,
4250N/A "concat", methodType(String.class, String.class));
4250N/AassertEquals("boojum", (String) cat.invokeExact("boo", "jum"));
4250N/AMethodHandle catTrace = foldArguments(cat, trace);
4250N/A// also prints "boo":
4250N/AassertEquals("boojum", (String) catTrace.invokeExact("boo", "jum"));
4250N/A }}
4250N/A }
4250N/A
3011N/A static void assertEquals(Object exp, Object act) {
3011N/A if (verbosity > 0)
3011N/A System.out.println("result: "+act);
3011N/A Assert.assertEquals(exp, act);
3011N/A }
3240N/A
3528N/A @Test public void testMethodHandlesSummary() throws Throwable {
3240N/A {{
3240N/A{} /// JAVADOC
3528N/AObject x, y; String s; int i;
3528N/AMethodType mt; MethodHandle mh;
3528N/AMethodHandles.Lookup lookup = MethodHandles.lookup();
3528N/A// mt is (char,char)String
3528N/Amt = MethodType.methodType(String.class, char.class, char.class);
3528N/Amh = lookup.findVirtual(String.class, "replace", mt);
3528N/As = (String) mh.invokeExact("daddy",'d','n');
3529N/A// invokeExact(Ljava/lang/String;CC)Ljava/lang/String;
4250N/AassertEquals(s, "nanny");
3528N/A// weakly typed invocation (using MHs.invoke)
3528N/As = (String) mh.invokeWithArguments("sappy", 'p', 'v');
4250N/AassertEquals(s, "savvy");
3528N/A// mt is (Object[])List
3528N/Amt = MethodType.methodType(java.util.List.class, Object[].class);
3528N/Amh = lookup.findStatic(java.util.Arrays.class, "asList", mt);
3528N/Aassert(mh.isVarargsCollector());
4182N/Ax = mh.invoke("one", "two");
4182N/A// invoke(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
4250N/AassertEquals(x, java.util.Arrays.asList("one","two"));
3528N/A// mt is (Object,Object,Object)Object
3528N/Amt = MethodType.genericMethodType(3);
3529N/Amh = mh.asType(mt);
3528N/Ax = mh.invokeExact((Object)1, (Object)2, (Object)3);
3529N/A// invokeExact(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
4250N/AassertEquals(x, java.util.Arrays.asList(1,2,3));
4250N/A// mt is ()int
3528N/Amt = MethodType.methodType(int.class);
3528N/Amh = lookup.findVirtual(java.util.List.class, "size", mt);
3528N/Ai = (int) mh.invokeExact(java.util.Arrays.asList(1,2,3));
3529N/A// invokeExact(Ljava/util/List;)I
3528N/Aassert(i == 3);
3528N/Amt = MethodType.methodType(void.class, String.class);
3528N/Amh = lookup.findVirtual(java.io.PrintStream.class, "println", mt);
3528N/Amh.invokeExact(System.out, "Hello, world.");
3529N/A// invokeExact(Ljava/io/PrintStream;Ljava/lang/String;)V
3528N/A{}
3240N/A }}
3240N/A }
3240N/A
4250N/A @Test public void testAsSpreader() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodHandle equals = publicLookup()
4250N/A .findVirtual(String.class, "equals", methodType(boolean.class, Object.class));
4250N/Aassert( (boolean) equals.invokeExact("me", (Object)"me"));
4250N/Aassert(!(boolean) equals.invokeExact("me", (Object)"thee"));
4250N/A// spread both arguments from a 2-array:
4250N/AMethodHandle eq2 = equals.asSpreader(Object[].class, 2);
4250N/Aassert( (boolean) eq2.invokeExact(new Object[]{ "me", "me" }));
4250N/Aassert(!(boolean) eq2.invokeExact(new Object[]{ "me", "thee" }));
4250N/A// spread both arguments from a String array:
4250N/AMethodHandle eq2s = equals.asSpreader(String[].class, 2);
4250N/Aassert( (boolean) eq2s.invokeExact(new String[]{ "me", "me" }));
4250N/Aassert(!(boolean) eq2s.invokeExact(new String[]{ "me", "thee" }));
4250N/A// spread second arguments from a 1-array:
4250N/AMethodHandle eq1 = equals.asSpreader(Object[].class, 1);
4250N/Aassert( (boolean) eq1.invokeExact("me", new Object[]{ "me" }));
4250N/Aassert(!(boolean) eq1.invokeExact("me", new Object[]{ "thee" }));
4250N/A// spread no arguments from a 0-array or null:
4250N/AMethodHandle eq0 = equals.asSpreader(Object[].class, 0);
4250N/Aassert( (boolean) eq0.invokeExact("me", (Object)"me", new Object[0]));
4250N/Aassert(!(boolean) eq0.invokeExact("me", (Object)"thee", (Object[])null));
4250N/A// asSpreader and asCollector are approximate inverses:
4250N/Afor (int n = 0; n <= 2; n++) {
4250N/A for (Class<?> a : new Class<?>[]{Object[].class, String[].class, CharSequence[].class}) {
4250N/A MethodHandle equals2 = equals.asSpreader(a, n).asCollector(a, n);
4250N/A assert( (boolean) equals2.invokeWithArguments("me", "me"));
4250N/A assert(!(boolean) equals2.invokeWithArguments("me", "thee"));
4250N/A }
4250N/A}
4250N/AMethodHandle caToString = publicLookup()
4250N/A .findStatic(Arrays.class, "toString", methodType(String.class, char[].class));
4250N/AassertEquals("[A, B, C]", (String) caToString.invokeExact("ABC".toCharArray()));
4250N/AMethodHandle caString3 = caToString.asCollector(char[].class, 3);
4250N/AassertEquals("[A, B, C]", (String) caString3.invokeExact('A', 'B', 'C'));
4250N/AMethodHandle caToString2 = caString3.asSpreader(char[].class, 2);
4250N/AassertEquals("[A, B, C]", (String) caToString2.invokeExact('A', "BC".toCharArray()));
4250N/A }}
4250N/A }
4250N/A
4250N/A @Test public void testAsCollector() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodHandle deepToString = publicLookup()
4250N/A .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));
4250N/AassertEquals("[won]", (String) deepToString.invokeExact(new Object[]{"won"}));
4250N/AMethodHandle ts1 = deepToString.asCollector(Object[].class, 1);
4250N/AassertEquals(methodType(String.class, Object.class), ts1.type());
4250N/A//assertEquals("[won]", (String) ts1.invokeExact( new Object[]{"won"})); //FAIL
4250N/AassertEquals("[[won]]", (String) ts1.invokeExact((Object) new Object[]{"won"}));
4250N/A// arrayType can be a subtype of Object[]
4250N/AMethodHandle ts2 = deepToString.asCollector(String[].class, 2);
4250N/AassertEquals(methodType(String.class, String.class, String.class), ts2.type());
4250N/AassertEquals("[two, too]", (String) ts2.invokeExact("two", "too"));
4250N/AMethodHandle ts0 = deepToString.asCollector(Object[].class, 0);
4250N/AassertEquals("[]", (String) ts0.invokeExact());
4250N/A// collectors can be nested, Lisp-style
4250N/AMethodHandle ts22 = deepToString.asCollector(Object[].class, 3).asCollector(String[].class, 2);
4250N/AassertEquals("[A, B, [C, D]]", ((String) ts22.invokeExact((Object)'A', (Object)"B", "C", "D")));
4250N/A// arrayType can be any primitive array type
4250N/AMethodHandle bytesToString = publicLookup()
4250N/A .findStatic(Arrays.class, "toString", methodType(String.class, byte[].class))
4250N/A .asCollector(byte[].class, 3);
4250N/AassertEquals("[1, 2, 3]", (String) bytesToString.invokeExact((byte)1, (byte)2, (byte)3));
4250N/AMethodHandle longsToString = publicLookup()
4250N/A .findStatic(Arrays.class, "toString", methodType(String.class, long[].class))
4250N/A .asCollector(long[].class, 1);
4250N/AassertEquals("[123]", (String) longsToString.invokeExact((long)123));
4250N/A }}
4250N/A }
4250N/A
5455N/A @SuppressWarnings("rawtypes")
3528N/A @Test public void testAsVarargsCollector() throws Throwable {
3528N/A {{
3528N/A{} /// JAVADOC
4250N/AMethodHandle deepToString = publicLookup()
4250N/A .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));
4250N/AMethodHandle ts1 = deepToString.asVarargsCollector(Object[].class);
4250N/AassertEquals("[won]", (String) ts1.invokeExact( new Object[]{"won"}));
4250N/AassertEquals("[won]", (String) ts1.invoke( new Object[]{"won"}));
4250N/AassertEquals("[won]", (String) ts1.invoke( "won" ));
4250N/AassertEquals("[[won]]", (String) ts1.invoke((Object) new Object[]{"won"}));
4250N/A// findStatic of Arrays.asList(...) produces a variable arity method handle:
3528N/AMethodHandle asList = publicLookup()
4250N/A .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class));
4250N/AassertEquals(methodType(List.class, Object[].class), asList.type());
4250N/Aassert(asList.isVarargsCollector());
4182N/AassertEquals("[]", asList.invoke().toString());
4182N/AassertEquals("[1]", asList.invoke(1).toString());
4182N/AassertEquals("[two, too]", asList.invoke("two", "too").toString());
4250N/AString[] argv = { "three", "thee", "tee" };
4182N/AassertEquals("[three, thee, tee]", asList.invoke(argv).toString());
4250N/AassertEquals("[three, thee, tee]", asList.invoke((Object[])argv).toString());
4182N/AList ls = (List) asList.invoke((Object)argv);
3528N/AassertEquals(1, ls.size());
3528N/AassertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));
3528N/A }}
3528N/A }
3528N/A
4250N/A @Test public void testAsFixedArity() throws Throwable {
3528N/A {{
3528N/A{} /// JAVADOC
4250N/AMethodHandle asListVar = publicLookup()
3528N/A .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
3528N/A .asVarargsCollector(Object[].class);
4250N/AMethodHandle asListFix = asListVar.asFixedArity();
4250N/AassertEquals("[1]", asListVar.invoke(1).toString());
4250N/AException caught = null;
4250N/Atry { asListFix.invoke((Object)1); }
4250N/Acatch (Exception ex) { caught = ex; }
4250N/Aassert(caught instanceof ClassCastException);
4250N/AassertEquals("[two, too]", asListVar.invoke("two", "too").toString());
4250N/Atry { asListFix.invoke("two", "too"); }
4250N/Acatch (Exception ex) { caught = ex; }
4250N/Aassert(caught instanceof WrongMethodTypeException);
4250N/AObject[] argv = { "three", "thee", "tee" };
4250N/AassertEquals("[three, thee, tee]", asListVar.invoke(argv).toString());
4250N/AassertEquals("[three, thee, tee]", asListFix.invoke(argv).toString());
4250N/AassertEquals(1, ((List) asListVar.invoke((Object)argv)).size());
4250N/AassertEquals("[three, thee, tee]", asListFix.invoke((Object)argv).toString());
4250N/A }}
4250N/A }
4250N/A
4250N/A @Test public void testAsTypeCornerCases() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodHandle i2s = publicLookup()
4250N/A .findVirtual(Integer.class, "toString", methodType(String.class));
4250N/Ai2s = i2s.asType(i2s.type().unwrap());
4250N/AMethodHandle l2s = publicLookup()
4250N/A .findVirtual(Long.class, "toString", methodType(String.class));
4250N/Al2s = l2s.asType(l2s.type().unwrap());
4250N/A
4250N/AException caught = null;
4250N/Atry { i2s.asType(methodType(String.class, String.class)); }
4250N/Acatch (Exception ex) { caught = ex; }
4250N/Aassert(caught instanceof WrongMethodTypeException);
4250N/A
4250N/Ai2s.asType(methodType(String.class, byte.class));
4250N/Ai2s.asType(methodType(String.class, Byte.class));
4250N/Ai2s.asType(methodType(String.class, Character.class));
4250N/Ai2s.asType(methodType(String.class, Integer.class));
4250N/Al2s.asType(methodType(String.class, byte.class));
4250N/Al2s.asType(methodType(String.class, Byte.class));
4250N/Al2s.asType(methodType(String.class, Character.class));
4250N/Al2s.asType(methodType(String.class, Integer.class));
4250N/Al2s.asType(methodType(String.class, Long.class));
4250N/A
4250N/Acaught = null;
4250N/Atry { i2s.asType(methodType(String.class, Long.class)); }
4250N/Acatch (Exception ex) { caught = ex; }
4250N/Aassert(caught instanceof WrongMethodTypeException);
4250N/A
4250N/AMethodHandle i2sGen = i2s.asType(methodType(String.class, Object.class));
4250N/AMethodHandle l2sGen = l2s.asType(methodType(String.class, Object.class));
4250N/A
4250N/Ai2sGen.invoke(42); // int -> Integer -> Object -> Integer -> int
4250N/Ai2sGen.invoke((byte)4); // byte -> Byte -> Object -> Byte -> byte -> int
4250N/Al2sGen.invoke(42); // int -> Integer -> Object -> Integer -> int
4250N/Al2sGen.invoke((byte)4); // byte -> Byte -> Object -> Byte -> byte -> int
4250N/Al2sGen.invoke(0x420000000L);
4250N/A
4250N/Acaught = null;
4250N/Atry { i2sGen.invoke(0x420000000L); } // long -> Long -> Object -> Integer CCE
4250N/Acatch (Exception ex) { caught = ex; }
4250N/Aassert(caught instanceof ClassCastException);
4250N/A
4250N/Acaught = null;
4250N/Atry { i2sGen.invoke("asdf"); } // String -> Object -> Integer CCE
4250N/Acatch (Exception ex) { caught = ex; }
4250N/Aassert(caught instanceof ClassCastException);
3528N/A{}
3528N/A }}
3528N/A }
4250N/A
4250N/A @Test public void testMutableCallSite() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMutableCallSite name = new MutableCallSite(MethodType.methodType(String.class));
4250N/AMethodHandle MH_name = name.dynamicInvoker();
4250N/AMethodType MT_str1 = MethodType.methodType(String.class);
4250N/AMethodHandle MH_upcase = MethodHandles.lookup()
4250N/A .findVirtual(String.class, "toUpperCase", MT_str1);
4250N/AMethodHandle worker1 = MethodHandles.filterReturnValue(MH_name, MH_upcase);
4250N/Aname.setTarget(MethodHandles.constant(String.class, "Rocky"));
4250N/AassertEquals("ROCKY", (String) worker1.invokeExact());
4250N/Aname.setTarget(MethodHandles.constant(String.class, "Fred"));
4250N/AassertEquals("FRED", (String) worker1.invokeExact());
4250N/A// (mutation can be continued indefinitely)
4250N/A/*
4250N/A * </pre></blockquote>
4250N/A * <p>
4250N/A * The same call site may be used in several places at once.
4250N/A * <blockquote><pre>
4250N/A */
4250N/AMethodType MT_str2 = MethodType.methodType(String.class, String.class);
4250N/AMethodHandle MH_cat = lookup().findVirtual(String.class,
4250N/A "concat", methodType(String.class, String.class));
4250N/AMethodHandle MH_dear = MethodHandles.insertArguments(MH_cat, 1, ", dear?");
4250N/AMethodHandle worker2 = MethodHandles.filterReturnValue(MH_name, MH_dear);
4250N/AassertEquals("Fred, dear?", (String) worker2.invokeExact());
4250N/Aname.setTarget(MethodHandles.constant(String.class, "Wilma"));
4250N/AassertEquals("WILMA", (String) worker1.invokeExact());
4250N/AassertEquals("Wilma, dear?", (String) worker2.invokeExact());
4250N/A{}
4250N/A }}
4250N/A }
4250N/A
4250N/A @Test public void testSwitchPoint() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/AMethodHandle MH_strcat = MethodHandles.lookup()
4250N/A .findVirtual(String.class, "concat", MethodType.methodType(String.class, String.class));
4250N/ASwitchPoint spt = new SwitchPoint();
4280N/Aassert(!spt.hasBeenInvalidated());
4250N/A// the following steps may be repeated to re-use the same switch point:
4250N/AMethodHandle worker1 = MH_strcat;
4250N/AMethodHandle worker2 = MethodHandles.permuteArguments(MH_strcat, MH_strcat.type(), 1, 0);
4250N/AMethodHandle worker = spt.guardWithTest(worker1, worker2);
4250N/AassertEquals("method", (String) worker.invokeExact("met", "hod"));
4250N/ASwitchPoint.invalidateAll(new SwitchPoint[]{ spt });
4280N/Aassert(spt.hasBeenInvalidated());
4250N/AassertEquals("hodmet", (String) worker.invokeExact("met", "hod"));
4250N/A{}
4250N/A }}
4250N/A }
4250N/A
5452N/A @Test public void testFoldArguments2() throws Throwable {
5452N/A {{
5452N/A{} /// JAVADOC
5452N/A// argument-based dispatch for methods of the form boolean x.___(y: String)
5452N/ALookup lookup = publicLookup();
5452N/A// first, a tracing hack:
5452N/AMethodHandle println = lookup.findVirtual(java.io.PrintStream.class, "println", methodType(void.class, String.class));
5452N/AMethodHandle arrayToString = lookup.findStatic(Arrays.class, "toString", methodType(String.class, Object[].class));
5452N/AMethodHandle concat = lookup.findVirtual(String.class, "concat", methodType(String.class, String.class));
5452N/AMethodHandle arrayToString_DIS = filterReturnValue(arrayToString, concat.bindTo("DIS:"));
5452N/AMethodHandle arrayToString_INV = filterReturnValue(arrayToString, concat.bindTo("INV:"));
5452N/AMethodHandle printArgs_DIS = filterReturnValue(arrayToString_DIS, println.bindTo(System.out)).asVarargsCollector(Object[].class);
5452N/AMethodHandle printArgs_INV = filterReturnValue(arrayToString_INV, println.bindTo(System.out)).asVarargsCollector(Object[].class);
5452N/A// metaobject protocol:
5452N/AMethodType mtype = methodType(boolean.class, String.class);
5452N/AMethodHandle findVirtual = lookup.findVirtual(Lookup.class,
5452N/A "findVirtual", methodType(MethodHandle.class, Class.class, String.class, MethodType.class));
5452N/AMethodHandle getClass = lookup.findVirtual(Object.class,
5452N/A "getClass", methodType(Class.class));
5452N/AMethodHandle dispatch = findVirtual;
5452N/Adispatch = filterArguments(dispatch, 1, getClass);
5452N/Adispatch = insertArguments(dispatch, 3, mtype);
5452N/Adispatch = dispatch.bindTo(lookup);
5452N/AassertEquals(methodType(MethodHandle.class, Object.class, String.class), dispatch.type());
5452N/AMethodHandle invoker = invoker(mtype.insertParameterTypes(0, Object.class));
5452N/A// wrap tracing around the dispatch and invoke steps:
5452N/Adispatch = foldArguments(dispatch, printArgs_DIS.asType(dispatch.type().changeReturnType(void.class)));
5452N/Ainvoker = foldArguments(invoker, printArgs_INV.asType(invoker.type().changeReturnType(void.class)));
5452N/Ainvoker = dropArguments(invoker, 2, String.class); // ignore selector
5452N/A// compose the dispatcher and the invoker:
5452N/AMethodHandle invokeDispatched = foldArguments(invoker, dispatch);
5452N/AObject x = "football", y = new java.util.Scanner("bar");
5452N/Aassert( (boolean) invokeDispatched.invokeExact(x, "startsWith", "foo"));
5452N/Aassert(!(boolean) invokeDispatched.invokeExact(x, "startsWith", "#"));
5452N/Aassert( (boolean) invokeDispatched.invokeExact(x, "endsWith", "all"));
5452N/Aassert(!(boolean) invokeDispatched.invokeExact(x, "endsWith", "foo"));
5452N/Aassert( (boolean) invokeDispatched.invokeExact(y, "hasNext", "[abc]+[rst]"));
5452N/Aassert(!(boolean) invokeDispatched.invokeExact(y, "hasNext", "[123]+[789]"));
5452N/A }}
5452N/A }
5452N/A
4250N/A /* ---- TEMPLATE ----
4250N/A @Test public void testFoo() throws Throwable {
4250N/A {{
4250N/A{} /// JAVADOC
4250N/A{}
4250N/A }}
4250N/A }
4250N/A */
3240N/A}