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.service; 016 017import org.apache.hivemind.Location; 018 019/** 020 * Service used to link two other services together using event notifications. The service producer 021 * will have the consumer registered as a listener. 022 * 023 * @author Howard Lewis Ship 024 */ 025public interface EventLinker 026{ 027 /** 028 * Adds the consumer as a listener of events published by the producer. Typically, the producer 029 * is a service, and the consumer is some other service's core implementation. 030 * 031 * @param producer 032 * the object which will be publishing the events. 033 * @param eventSetName 034 * the name of an event set; the consumer will only be registered for that set of 035 * events. 036 * @param consumer 037 * the object which will be added as a listener. 038 * @param location 039 * used when reporting errors, may be null 040 * @return true on success, false if there was any failure (which may mean only partial 041 * registration). 042 */ 043 public void addEventListener(Object producer, String eventSetName, Object consumer, 044 Location location); 045}