96 lines
4.4 KiB
Java
96 lines
4.4 KiB
Java
/*
|
|
* 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;
|
|
}
|