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.proxy;
  
  import java.util.Collection;
  import java.util.concurrent.Callable;
  
  import org.osgi.framework.Bundle;
  
  /**
   * The proxy manager service allows clients to generate and manage proxies.
   */
  public interface ProxyManager 
  {
    /**
     * Create a proxy that delegates to an object instance which may change
     * over time
     * 
     * @param clientBundle The bundle providing the class to be proxied
     * @param classes  The interfaces and/or classes to be proxied
     * @param dispatcher A {@link Callable} that will called each time the proxy 
     *                   is invoked to locate the object to delegate to
     * @param template A template object for the proxy, may be null if only interfaces
     *                 need to be proxied. Supplying a templates typically offer a 
     *                 significant performance boost to the resulting proxy.
     * @return A proxy object that delegates to real objects under the covers
     * @throws UnableToProxyException
     */
    public Object createDelegatingProxy(Bundle clientBundle, Collection<Class<?>> classes, Callable<Object> dispatcher, Object template) throws UnableToProxyException;
    
    /**
     * Creates a proxy that invokes the supplied {@link InvocationListener} 
     * immediately before and after any non-private method is called.
     * 
     * @param clientBundle
     * @param classes
     * @param delegate
     * @param wrapper
     * @return
     * @throws UnableToProxyException
     */
    public Object createInterceptingProxy(Bundle clientBundle, Collection<Class<?>> classes, 
        Object delegate, InvocationListener wrapper) throws UnableToProxyException;
    
    /**
     * Creates a single proxy that both delegates and intercepts. See
     * ProxyManager.createDelegatingProxy(Bundle, Collection, Callable) 
     * and ProxyManager.createInterceptingProxy(Bundle, Collection, Object, InvocationListener)
     * 
     * @param clientBundle
     * @param classes
     * @param dispatcher
     * @param template A template object for the proxy, may be null if only interfaces
     *                 need to be proxied. Supplying a templates typically offer a 
     *                 significant performance boost to the resulting proxy.
     * @param wrapper
     * @return
     * @throws UnableToProxyException
     */
    public Object createDelegatingInterceptingProxy(Bundle clientBundle, Collection<Class<?>> classes, 
        Callable<Object> dispatcher, Object template, InvocationListener wrapper) throws UnableToProxyException;
    
    /**
     * This method unwraps the provided proxy returning the target object.
     * 
     * @param proxy the proxy to unwrap.
     * @return      the target object.
     */
    public Callable<Object> unwrap(Object proxy);
    /**
     * Returns true if and only if the specified object was generated by the ProxyManager. See
     * ProxyManager.createDelegatingProxy(Bundle, Collection, Callable) for details on how to create a proxy. 
     * @param proxy The proxy object to test
     * @return      true if it is a proxy, false otherwise.
     */
    public boolean isProxy(Object proxy);
  }
  