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   * 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
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   */
  
  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;
  }
  