Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ConfigurationEvent |
|
| 1.0;1 |
1 | /* | |
2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
3 | * contributor license agreements. See the NOTICE file distributed with | |
4 | * this work for additional information regarding copyright ownership. | |
5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
6 | * (the "License"); you may not use this file except in compliance with | |
7 | * the License. You may obtain a copy of the License at | |
8 | * | |
9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
10 | * | |
11 | * Unless required by applicable law or agreed to in writing, software | |
12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
14 | * See the License for the specific language governing permissions and | |
15 | * limitations under the License. | |
16 | */ | |
17 | package org.apache.commons.configuration.event; | |
18 | ||
19 | import java.util.EventObject; | |
20 | ||
21 | /** | |
22 | * <p> | |
23 | * An event class for reporting updates on a configuration object. | |
24 | * </p> | |
25 | * <p> | |
26 | * Event objects of this type are used for "raw" events, i.e. | |
27 | * unfiltered modifications of any kind. A level with semantically higher events | |
28 | * (e.g. for property changes) may be built on top of this fundamental event | |
29 | * mechanism. | |
30 | * </p> | |
31 | * <p> | |
32 | * Each event can contain the following data: | |
33 | * <ul> | |
34 | * <li>A source object, which is usually the configuration object that was | |
35 | * modified.</li> | |
36 | * <li>The event's type. This is a numeric value that corresponds to constant | |
37 | * declarations in concrete configuration classes. It describes what exactly has | |
38 | * happended.</li> | |
39 | * <li>If available, the name of the property whose modification caused the | |
40 | * event.</li> | |
41 | * <li>If available, the value of the property that caused this event.</li> | |
42 | * <li>A flag whether this event was generated before or after the update of | |
43 | * the source configuration. A modification of a configuration typically causes | |
44 | * two events: one event before and one event after the modification is | |
45 | * performed. This allows event listeners to react at the correct point of time.</li> | |
46 | * </ul> | |
47 | * </p> | |
48 | * <p> | |
49 | * The following standard events are generated by typical configuration | |
50 | * implementations (the constants for the event types are defined in | |
51 | * <code>{@link org.apache.commons.configuration.AbstractConfiguration}</code>): | |
52 | * <dl> | |
53 | * <dt>EVENT_ADD_PROPERTY</dt> | |
54 | * <dd>This event is triggered for each call of the <code>addProperty()</code> | |
55 | * method of a configuration object. It contains the name of the property, to | |
56 | * which new data is added, and the value object that is added to this property | |
57 | * (this may be an array or a list if multiple values are added).</dd> | |
58 | * <dt>EVENT_SET_PROPERTY</dt> | |
59 | * <dd>Calling the <code>setProperty()</code> method triggers this event. The | |
60 | * event object stores the name of the affected property and its new value.</dd> | |
61 | * <dt>EVENT_CLEAR_PROPERTY</dt> | |
62 | * <dd>If a property is removed from a configuration (by calling the | |
63 | * <code>clearProperty()</code> method), an event of this type is fired. In | |
64 | * this case the event object only stores the name of the removed property, the | |
65 | * value is <b>null</b>.</dd> | |
66 | * <dt>EVENT_CLEAR</dt> | |
67 | * <dd>This event is fired when the whole configuration is cleared. The | |
68 | * corresponding event object contains no additional data.</dd> | |
69 | * </dl> | |
70 | * </p> | |
71 | * | |
72 | * @author <a | |
73 | * href="http://jakarta.apache.org/commons/configuration/team-list.html">Commons | |
74 | * Configuration team</a> | |
75 | * @version $Id: ConfigurationEvent.java 443105 2006-09-13 20:04:01Z oheger $ | |
76 | * @since 1.3 | |
77 | */ | |
78 | public class ConfigurationEvent extends EventObject | |
79 | { | |
80 | /** | |
81 | * The serial version UID. | |
82 | */ | |
83 | private static final long serialVersionUID = 3277238219073504136L; | |
84 | ||
85 | /** Stores the event type. */ | |
86 | private int type; | |
87 | ||
88 | /** Stores the property name. */ | |
89 | private String propertyName; | |
90 | ||
91 | /** Stores the property value. */ | |
92 | private Object propertyValue; | |
93 | ||
94 | /** Stores the before update flag. */ | |
95 | private boolean beforeUpdate; | |
96 | ||
97 | /** | |
98 | * Creates a new instance of <code>ConfigurationEvent</code> and | |
99 | * initializes it. | |
100 | * | |
101 | * @param source the event source | |
102 | * @param type the event's type | |
103 | * @param propertyName the name of the affected property | |
104 | * @param propertyValue the value of the affected property | |
105 | * @param beforeUpdate the before update flag | |
106 | */ | |
107 | public ConfigurationEvent(Object source, int type, String propertyName, | |
108 | Object propertyValue, boolean beforeUpdate) | |
109 | { | |
110 | 479 | super(source); |
111 | 479 | this.type = type; |
112 | 479 | this.propertyName = propertyName; |
113 | 479 | this.propertyValue = propertyValue; |
114 | 479 | this.beforeUpdate = beforeUpdate; |
115 | 479 | } |
116 | ||
117 | /** | |
118 | * Returns the name of the affected property. This can be <b>null</b> if no | |
119 | * property change has lead to this event. | |
120 | * | |
121 | * @return the name of the property | |
122 | */ | |
123 | public String getPropertyName() | |
124 | { | |
125 | 285 | return propertyName; |
126 | } | |
127 | ||
128 | /** | |
129 | * Returns the value of the affected property if available. | |
130 | * | |
131 | * @return the value of the property; can be <b>null</b> | |
132 | */ | |
133 | public Object getPropertyValue() | |
134 | { | |
135 | 89 | return propertyValue; |
136 | } | |
137 | ||
138 | /** | |
139 | * Returns the type of this event. This describes the update process that | |
140 | * caused this event. | |
141 | * | |
142 | * @return the event's type | |
143 | */ | |
144 | public int getType() | |
145 | { | |
146 | 487 | return type; |
147 | } | |
148 | ||
149 | /** | |
150 | * Returns a flag if this event was generated before or after an update. | |
151 | * | |
152 | * @return <b>true</b> if this event was generated before an update; | |
153 | * <b>false</b> otherwise | |
154 | */ | |
155 | public boolean isBeforeUpdate() | |
156 | { | |
157 | 338 | return beforeUpdate; |
158 | } | |
159 | } |