/* * Copyright (c) 2008, 2009, 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. */ package java.dyn; /** * {@code InvokeDynamic} is a class with neither methods nor instances, * which serves only as a syntactic marker in Java source code for * an {@code invokedynamic} instruction. * (See the package information for specifics on this instruction.) *
* The {@code invokedynamic} instruction is incomplete without a target method. * The target method is a property of the reified {@linkplain CallSite call site object} * which is linked to each active {@code invokedynamic} instruction. * The call site object is initially produced by a * {@linkplain java.dyn.Linkage#registerBootstrapMethod(Class, MethodHandle) bootstrap method} * associated with the class whose bytecodes include the dynamic call site. *
* The type {@code InvokeDynamic} has no particular meaning as a * class or interface supertype, or an object type; it can never be instantiated. * Logically, it denotes a source of all dynamically typed methods. * It may be viewed as a pure syntactic marker of static calls. * It may be imported for ease of use. *
* Here are some examples: *
* Object x; String s; int i;
* x = InvokeDynamic.greet("world"); // greet(Ljava/lang/String;)Ljava/lang/Object;
* s = InvokeDynamic.<String>hail(x); // hail(Ljava/lang/Object;)Ljava/lang/String;
* InvokeDynamic.<void>cogito(); // cogito()V
* i = InvokeDynamic.<int>#"op:+"(2, 3); // "op:+"(II)I
*
* Each of the above calls generates a single invokedynamic instruction
* with the name-and-type descriptors indicated in the comments.
* The argument types are taken directly from the actual arguments,
* while the return type is taken from the type parameter.
* (This type parameter may be a primtive, and it defaults to {@code Object}.)
* The final example uses a special syntax for uttering non-Java names.
* Any name legal to the JVM may be given between the double quotes.
* None of these calls is complete without a bootstrap method,
* which must be registered by the static initializer of the enclosing class.
* @author John Rose, JSR 292 EG
*/
@MethodHandle.PolymorphicSignature
public final class InvokeDynamic {
private InvokeDynamic() { throw new InternalError(); } // do not instantiate
// no statically defined static methods
}