001package org.apache.turbine.services; 002 003 004/* 005 * Licensed to the Apache Software Foundation (ASF) under one 006 * or more contributor license agreements. See the NOTICE file 007 * distributed with this work for additional information 008 * regarding copyright ownership. The ASF licenses this file 009 * to you under the Apache License, Version 2.0 (the 010 * "License"); you may not use this file except in compliance 011 * with the License. You may obtain a copy of the License at 012 * 013 * http://www.apache.org/licenses/LICENSE-2.0 014 * 015 * Unless required by applicable law or agreed to in writing, 016 * software distributed under the License is distributed on an 017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 018 * KIND, either express or implied. See the License for the 019 * specific language governing permissions and limitations 020 * under the License. 021 */ 022 023 024/** 025 * Classes that implement this interface need initialization before 026 * they can work. 027 * 028 * These classes rely also on an <code>InitableBroker</code> that 029 * ensures that there is only one instance of the class in the system, 030 * and handles dependencies between <code>Initables</code>. 031 * 032 * @author <a href="mailto:burton@apache.org">Kevin Burton</a> 033 * @author <a href="mailto:krzewski@e-point.pl">Rafal Krzewski</a> 034 * @version $Id$ 035 */ 036public interface Initable 037{ 038 /** 039 * Provides an Initable with a reference to the InitableBroker 040 * that instantiated this object, so that it can access other 041 * Initables. 042 * 043 * @param broker The InitableBroker that instantiated this object. 044 */ 045 void setInitableBroker(InitableBroker broker); 046 047 /** 048 * Performs early initialization of an Initable 049 * 050 * During the startup of the system, different objects may be 051 * passed to your class using this method. It should ignore any 052 * objects that it doesn't need or understand. 053 * 054 * After the class changes its internal state so that getInit() 055 * returns true, this method will be called no more, and late 056 * initialization will not be performed. 057 * 058 * If your class relies on early initialization, and the object it 059 * expects was not received, you can use late initialization to 060 * throw an exception and complain. 061 * 062 * @param data An Object to use for initialization activities. 063 * @throws InitializationException if initialization of this 064 * class was not successful. 065 */ 066 void init(Object data) throws InitializationException; 067 068 /** 069 * Performs late initialization of an Initable. 070 * 071 * When your class is being requested from an InitableBroker, it 072 * will call getInit(), and if it returns false, this method will 073 * be invoked. 074 * 075 * @throws InitializationException if initialization of this 076 * class was not successful. 077 */ 078 void init() throws InitializationException; 079 080 /** 081 * Returns an <code>Initable</code> to an uninitialized state. 082 * 083 * <p>This method must release all resources allocated by the 084 * <code>Initable</code> implementation, and resetting its internal state. 085 * You may chose to implement this operation or not. If you support 086 * this operation, getInit() should return false after successful 087 * shutdown of the service. 088 */ 089 void shutdown(); 090 091 /** 092 * Returns initialization status of an Initable. 093 * 094 * @return Initialization status of an Initable. 095 */ 096 boolean getInit(); 097}