001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.hivemind.internal;
016
017import org.apache.hivemind.InterceptorStack;
018import org.apache.hivemind.Locatable;
019
020/**
021 * A contribution to a service extension point that creates an interceptor.
022 * 
023 * @author Howard Lewis Ship
024 */
025public interface ServiceInterceptorContribution extends Locatable
026{
027    /**
028     * Returns the name of the service interceptor.  The name is used for ordering the
029     * service interceptor with respect to other interceptors.  The name defaults
030     * to the factoryServiceId if no name is specified.
031     * @return the name of the service interceptor
032     * @since 1.1
033     */
034    public String getName();
035    
036    /**
037     * Returns the id of the factory that creates the interceptor. Interceptor factories are simply
038     * another HiveMind service, one that implements
039     * {@link org.apache.hivemind.ServiceInterceptorFactory}.
040     */
041    public String getFactoryServiceId();
042
043    /**
044     * Invoked to actually create the interceptor and push it onto the stack.
045     */
046    public void createInterceptor(InterceptorStack stack);
047
048    /**
049     * Returns a list interceptors service ids as a comma seperated list. The behavior provided by
050     * these interceptors should <em>precede</em> the behavior of this interceptor.
051     * <p>
052     * Each service id is fully qualified. May return null.
053     */
054    public String getPrecedingInterceptorIds();
055
056    /**
057     * As {@link #getPrecedingInterceptorIds()}, but the indicating interceptors's behavior should
058     * <em>follow</em> this interceptor's.
059     */
060
061    public String getFollowingInterceptorIds();
062}