| /* |
| * Copyright (c) 1999, 2006, 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.lang.reflect; |
| |
| /** |
| * {@code InvocationHandler} is the interface implemented by |
| * the <i>invocation handler</i> of a proxy instance. |
| * |
| * <p>Each proxy instance has an associated invocation handler. |
| * When a method is invoked on a proxy instance, the method |
| * invocation is encoded and dispatched to the {@code invoke} |
| * method of its invocation handler. |
| * |
| * @author Peter Jones |
| * @see Proxy |
| * @since 1.3 |
| */ |
| public interface InvocationHandler { |
| |
| /** |
| * Processes a method invocation on a proxy instance and returns |
| * the result. This method will be invoked on an invocation handler |
| * when a method is invoked on a proxy instance that it is |
| * associated with. |
| * |
| * @param proxy the proxy instance that the method was invoked on |
| * |
| * @param method the {@code Method} instance corresponding to |
| * the interface method invoked on the proxy instance. The declaring |
| * class of the {@code Method} object will be the interface that |
| * the method was declared in, which may be a superinterface of the |
| * proxy interface that the proxy class inherits the method through. |
| * |
| * @param args an array of objects containing the values of the |
| * arguments passed in the method invocation on the proxy instance, |
| * or {@code null} if interface method takes no arguments. |
| * Arguments of primitive types are wrapped in instances of the |
| * appropriate primitive wrapper class, such as |
| * {@code java.lang.Integer} or {@code java.lang.Boolean}. |
| * |
| * @return the value to return from the method invocation on the |
| * proxy instance. If the declared return type of the interface |
| * method is a primitive type, then the value returned by |
| * this method must be an instance of the corresponding primitive |
| * wrapper class; otherwise, it must be a type assignable to the |
| * declared return type. If the value returned by this method is |
| * {@code null} and the interface method's return type is |
| * primitive, then a {@code NullPointerException} will be |
| * thrown by the method invocation on the proxy instance. If the |
| * value returned by this method is otherwise not compatible with |
| * the interface method's declared return type as described above, |
| * a {@code ClassCastException} will be thrown by the method |
| * invocation on the proxy instance. |
| * |
| * @throws Throwable the exception to throw from the method |
| * invocation on the proxy instance. The exception's type must be |
| * assignable either to any of the exception types declared in the |
| * {@code throws} clause of the interface method or to the |
| * unchecked exception types {@code java.lang.RuntimeException} |
| * or {@code java.lang.Error}. If a checked exception is |
| * thrown by this method that is not assignable to any of the |
| * exception types declared in the {@code throws} clause of |
| * the interface method, then an |
| * {@link UndeclaredThrowableException} containing the |
| * exception that was thrown by this method will be thrown by the |
| * method invocation on the proxy instance. |
| * |
| * @see UndeclaredThrowableException |
| */ |
| public Object invoke(Object proxy, Method method, Object[] args) |
| throws Throwable; |
| } |