1 package org.apache.turbine.services; 2 3 4 /* 5 * Licensed to the Apache Software Foundation (ASF) under one 6 * or more contributor license agreements. See the NOTICE file 7 * distributed with this work for additional information 8 * regarding copyright ownership. The ASF licenses this file 9 * to you under the Apache License, Version 2.0 (the 10 * "License"); you may not use this file except in compliance 11 * with the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, 16 * software distributed under the License is distributed on an 17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 18 * KIND, either express or implied. See the License for the 19 * specific language governing permissions and limitations 20 * under the License. 21 */ 22 23 24 /** 25 * Classes that implement this interface need initialization before 26 * they can work. 27 * 28 * These classes rely also on an <code>InitableBroker</code> that 29 * ensures that there is only one instance of the class in the system, 30 * and handles dependencies between <code>Initables</code>. 31 * 32 * @author <a href="mailto:burton@apache.org">Kevin Burton</a> 33 * @author <a href="mailto:krzewski@e-point.pl">Rafal Krzewski</a> 34 * @version $Id: Initable.java 1773378 2016-12-09 13:19:59Z tv $ 35 */ 36 public interface Initable 37 { 38 /** 39 * Provides an Initable with a reference to the InitableBroker 40 * that instantiated this object, so that it can access other 41 * Initables. 42 * 43 * @param broker The InitableBroker that instantiated this object. 44 */ 45 void setInitableBroker(InitableBroker broker); 46 47 /** 48 * Performs early initialization of an Initable 49 * 50 * During the startup of the system, different objects may be 51 * passed to your class using this method. It should ignore any 52 * objects that it doesn't need or understand. 53 * 54 * After the class changes its internal state so that getInit() 55 * returns true, this method will be called no more, and late 56 * initialization will not be performed. 57 * 58 * If your class relies on early initialization, and the object it 59 * expects was not received, you can use late initialization to 60 * throw an exception and complain. 61 * 62 * @param data An Object to use for initialization activities. 63 * @throws InitializationException if initialization of this 64 * class was not successful. 65 */ 66 void init(Object data) throws InitializationException; 67 68 /** 69 * Performs late initialization of an Initable. 70 * 71 * When your class is being requested from an InitableBroker, it 72 * will call getInit(), and if it returns false, this method will 73 * be invoked. 74 * 75 * @throws InitializationException if initialization of this 76 * class was not successful. 77 */ 78 void init() throws InitializationException; 79 80 /** 81 * Returns an <code>Initable</code> to an uninitialized state. 82 * 83 * <p>This method must release all resources allocated by the 84 * <code>Initable</code> implementation, and resetting its internal state. 85 * You may chose to implement this operation or not. If you support 86 * this operation, getInit() should return false after successful 87 * shutdown of the service. 88 */ 89 void shutdown(); 90 91 /** 92 * Returns initialization status of an Initable. 93 * 94 * @return Initialization status of an Initable. 95 */ 96 boolean getInit(); 97 }