01: package org.apache.turbine.services;
02:
03: /*
04: * Licensed to the Apache Software Foundation (ASF) under one
05: * or more contributor license agreements. See the NOTICE file
06: * distributed with this work for additional information
07: * regarding copyright ownership. The ASF licenses this file
08: * to you under the Apache License, Version 2.0 (the
09: * "License"); you may not use this file except in compliance
10: * with the License. You may obtain a copy of the License at
11: *
12: * http://www.apache.org/licenses/LICENSE-2.0
13: *
14: * Unless required by applicable law or agreed to in writing,
15: * software distributed under the License is distributed on an
16: * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17: * KIND, either express or implied. See the License for the
18: * specific language governing permissions and limitations
19: * under the License.
20: */
21:
22: /**
23: * Classes that implement this interface need initialization before
24: * they can work.
25: *
26: * These classes rely also on an <code>InitableBroker</code> that
27: * ensures that there is only one instance of the class in the system,
28: * and handles dependencies between <code>Initables</code>.
29: *
30: * @author <a href="mailto:burton@apache.org">Kevin Burton</a>
31: * @author <a href="mailto:krzewski@e-point.pl">Rafal Krzewski</a>
32: * @version $Id: Initable.java 534527 2007-05-02 16:10:59Z tv $
33: */
34: public interface Initable {
35: /**
36: * Provides an Initable with a reference to the InitableBroker
37: * that instantiated this object, so that it can access other
38: * Initables.
39: *
40: * @param broker The InitableBroker that instantiated this object.
41: */
42: void setInitableBroker(InitableBroker broker);
43:
44: /**
45: * Performs early initailization of an Initable
46: *
47: * During the startup of the system, different objects may be
48: * passed to your class using this method. It should ignore any
49: * objects that it doesn't need or understand.
50: *
51: * After the class changes its internal state so that getInit()
52: * returns true, this method will be called no more, and late
53: * initialization will not be performed.
54: *
55: * If your class relies on early initialization, and the object it
56: * expects was not received, you can use late initialization to
57: * throw an exception and complain.
58: *
59: * @param data An Object to use for initialization activities.
60: * @exception InitializationException if initilaization of this
61: * class was not successful.
62: */
63: void init(Object data) throws InitializationException;
64:
65: /**
66: * Performs late initialization of an Initable.
67: *
68: * When your class is being requested from an InitableBroker, it
69: * will call getInit(), and if it returns false, this method will
70: * be invoked.
71: *
72: * @exception InitializationException if initialization of this
73: * class was not successful.
74: */
75: void init() throws InitializationException;
76:
77: /**
78: * Returns an <code>Initable</code> to an uninitialized state.
79: *
80: * <p>This method must release all resources allocated by the
81: * <code>Initable</code> implementation, and resetting its internal state.
82: * You may chose to implement this operation or not. If you support
83: * this operation, getInit() should return false after successful
84: * shutdown of the service.
85: */
86: void shutdown();
87:
88: /**
89: * Returns initialization status of an Initable.
90: *
91: * @return Initialization status of an Initable.
92: */
93: boolean getInit();
94: }
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