1/* 2 * Copyright (c) 1999, 2006, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package javax.management; 27 28 29import java.util.List; 30import java.util.Vector; 31 32/** 33 * Provides an implementation of the {@link javax.management.NotificationFilter} interface. 34 * The filtering is performed on the notification type attribute. 35 * <P> 36 * Manages a list of enabled notification types. 37 * A method allows users to enable/disable as many notification types as required. 38 * <P> 39 * Then, before sending a notification to a listener registered with a filter, 40 * the notification broadcaster compares this notification type with all notification types 41 * enabled by the filter. The notification will be sent to the listener 42 * only if its filter enables this notification type. 43 * <P> 44 * Example: 45 * <BLOCKQUOTE> 46 * <PRE> 47 * NotificationFilterSupport myFilter = new NotificationFilterSupport(); 48 * myFilter.enableType("my_example.my_type"); 49 * myBroadcaster.addListener(myListener, myFilter, null); 50 * </PRE> 51 * </BLOCKQUOTE> 52 * The listener <CODE>myListener</CODE> will only receive notifications the type of which equals/starts with "my_example.my_type". 53 * 54 * @see javax.management.NotificationBroadcaster#addNotificationListener 55 * 56 * @since 1.5 57 */ 58public class NotificationFilterSupport implements NotificationFilter { 59 60 /* Serial version */ 61 private static final long serialVersionUID = 6579080007561786969L; 62 63 /** 64 * @serial {@link Vector} that contains the enabled notification types. 65 * The default value is an empty vector. 66 */ 67 private List<String> enabledTypes = new Vector<String>(); 68 69 70 /** 71 * Invoked before sending the specified notification to the listener. 72 * <BR>This filter compares the type of the specified notification with each enabled type. 73 * If the notification type matches one of the enabled types, 74 * the notification should be sent to the listener and this method returns <CODE>true</CODE>. 75 * 76 * @param notification The notification to be sent. 77 * @return <CODE>true</CODE> if the notification should be sent to the listener, <CODE>false</CODE> otherwise. 78 */ 79 public synchronized boolean isNotificationEnabled(Notification notification) { 80 81 String type = notification.getType(); 82 83 if (type == null) { 84 return false; 85 } 86 try { 87 for (String prefix : enabledTypes) { 88 if (type.startsWith(prefix)) { 89 return true; 90 } 91 } 92 } catch (java.lang.NullPointerException e) { 93 // Should never occurs... 94 return false; 95 } 96 return false; 97 } 98 99 /** 100 * Enables all the notifications the type of which starts with the specified prefix 101 * to be sent to the listener. 102 * <BR>If the specified prefix is already in the list of enabled notification types, 103 * this method has no effect. 104 * <P> 105 * Example: 106 * <BLOCKQUOTE> 107 * <PRE> 108 * // Enables all notifications the type of which starts with "my_example" to be sent. 109 * myFilter.enableType("my_example"); 110 * // Enables all notifications the type of which is "my_example.my_type" to be sent. 111 * myFilter.enableType("my_example.my_type"); 112 * </PRE> 113 * </BLOCKQUOTE> 114 * 115 * Note that: 116 * <BLOCKQUOTE><CODE> 117 * myFilter.enableType("my_example.*"); 118 * </CODE></BLOCKQUOTE> 119 * will no match any notification type. 120 * 121 * @param prefix The prefix. 122 * @exception java.lang.IllegalArgumentException The prefix parameter is null. 123 */ 124 public synchronized void enableType(String prefix) 125 throws IllegalArgumentException { 126 127 if (prefix == null) { 128 throw new IllegalArgumentException("The prefix cannot be null."); 129 } 130 if (!enabledTypes.contains(prefix)) { 131 enabledTypes.add(prefix); 132 } 133 } 134 135 /** 136 * Removes the given prefix from the prefix list. 137 * <BR>If the specified prefix is not in the list of enabled notification types, 138 * this method has no effect. 139 * 140 * @param prefix The prefix. 141 */ 142 public synchronized void disableType(String prefix) { 143 enabledTypes.remove(prefix); 144 } 145 146 /** 147 * Disables all notification types. 148 */ 149 public synchronized void disableAllTypes() { 150 enabledTypes.clear(); 151 } 152 153 154 /** 155 * Gets all the enabled notification types for this filter. 156 * 157 * @return The list containing all the enabled notification types. 158 */ 159 public synchronized Vector<String> getEnabledTypes() { 160 return (Vector<String>)enabledTypes; 161 } 162 163} 164