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/*
* Copyright 2000-2011 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
@SuppressWarnings({"UnusedDeclaration"})
class C {
// from http://download.java.net/jdk7/docs/api/java/lang/invoke/MethodHandle.html, "Usage examples"
void m() throws Throwable {
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
MethodHandle mh0 = lookup.findVirtual(String.class, "length", MethodType.methodType(int.class));
MethodHandle mh1 = MethodHandles.convertArguments(mh0, MethodType.methodType(Integer.class, String.class));
System.out.println((Integer) mh1.invokeExact("daddy"));
}
void supported() {
Object o = 42;
int i = (int) o;
String s = "";
int i1 = <error descr="Inconvertible types; cannot cast 'java.lang.String' to 'int'">(int) s</error>;
System.out.println(i);
m((int) o);
}
void unsupported() {
Object o = 42;
if (<error descr="Inconvertible types; cannot cast 'java.lang.Object' to 'int'">o instanceof int</error>) {
int i = (Integer) o;
System.out.println(i);
}
}
void m(int i) { }
void asLongs(Integer i) {
long l = (long) i;
}
}
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