content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.
   */
  package org.apache.aries.blueprint;
  
  import java.lang.reflect.Method;
  
  import org.osgi.service.blueprint.reflect.ComponentMetadata;
  
  /**
   * An Interceptor interface provides support for custom interceptor implementation.
   */
  public interface Interceptor {
      /**
       * This is called just before the method m is invocation.
       * @param cm : the component's metada
       * @param m: the method to be invoked
       * @param parameters: method parameters
       * @return token which will subsequently be passed to postCall
       * @throws Throwable
       */
      Object preCall(ComponentMetadata cm, Method m, Object... parameters) throws Throwable;
      
      /**
       * This method is called after the method m is invoked and returned normally.
       * @param cm: the component metadata
       * @param m: the method invoked
       * @param returnType : the return object
       * @param preCallToken token returned by preCall
       * @throws Throwable
       */
      void postCallWithReturn(ComponentMetadata cm, Method m, Object returnType, Object preCallToken) throws Throwable;
      
      /**
       * The method is called after the method m is invoked and causes an exception.
       * @param cm : the component metadata
       * @param m : the method invoked
       * @param ex : the <code>Throwable</code> thrown
       * @param preCallToken token returned by preCall
       * @throws Throwable
       */
      void postCallWithException(ComponentMetadata cm, Method m, Throwable ex, Object preCallToken) throws Throwable;
      
      
      /**
       * Return the rank of the interceptor, which is used to determine the order of the interceptors to be invoked
       * Rank is between Integer.MIN_VALUE and Integer.MAX_VALUE, interceptors are called in the order of highest value
       * rank first to lowest value rank last i.e. an interceptor with rank Integer.MAX_VALUE will be called before 
       * all others (except of the same rank).
       * @return the rank of the interceptor
       */
      int getRank();
  }
  