001/* MBeanNotificationInfo.java -- Information about a bean's notification. 002 Copyright (C) 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package javax.management; 039 040import java.util.Arrays; 041 042/** 043 * <p> 044 * Describes the notifications emitted by a management bean. 045 * An instance of this class is specific to notifications 046 * involving a particular type of object. A new instance 047 * should be created for each Java class used for notifications, 048 * and the Java class name forms the name of the instance. 049 * Each instance lists a number of notification types; these 050 * are not types in the sense of different Java classes, but 051 * instead form the names of notifications following the same 052 * syntax as Java property and package names. 053 * </p> 054 * <p> 055 * For instance, a management bean may emit two notifications 056 * containing {@link java.lang.String} objects. Both would be described 057 * using one instance of this class, with a member of the array 058 * returned by {@link #getNotifTypes()} for each one. If another 059 * notification containing a {@link java.util.Date} object were to 060 * be added, this would require a new instance of this class. 061 * </p> 062 * <p> 063 * The information in this class is immutable as standard. 064 * Of course, subclasses may change this, but this 065 * behaviour is not recommended. 066 * </p> 067 * 068 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 069 * @since 1.5 070 */ 071public class MBeanNotificationInfo 072 extends MBeanFeatureInfo 073 implements Cloneable 074{ 075 076 /** 077 * Compatible with JDK 1.5 078 */ 079 private static final long serialVersionUID = -3888371564530107064L; 080 081 /** 082 * The types of notification described by this instance. 083 * 084 * @serial the types of notification. 085 */ 086 private String[] types; 087 088 /** 089 * Constructs a new {@link MBeanNotificationInfo} with the 090 * specified name, description and notification types. The 091 * notification types array may be <code>null</code> or of 092 * zero length, in order to indicate the absence of any types. 093 * 094 * @param types an array of {@link java.lang.String} objects, 095 * containing the names of the notifications emitted 096 * of this Java type. The names use the dot notation 097 * familiar from Java property and package names. 098 * @param name the name of the Java class the notifications described 099 * by this object are instances of. 100 * @param description a description of the data. 101 * @throws IllegalArgumentException for some reason... 102 */ 103 public MBeanNotificationInfo(String[] types, String name, 104 String description) 105 { 106 super(name, description); 107 this.types = types; 108 } 109 110 /** 111 * Returns a clone of this instance. The clone is created 112 * using just the method provided by {@link java.lang.Object}. 113 * Thus, the clone is just a shallow clone as returned by 114 * that method, and does not contain any deeper cloning based 115 * on the subject of this class. 116 * 117 * @return a clone of this instance. 118 * @see java.lang.Cloneable 119 */ 120 public Object clone() 121 { 122 try 123 { 124 return super.clone(); 125 } 126 catch (CloneNotSupportedException e) 127 { 128 /* This shouldn't happen; we implement Cloneable */ 129 throw new IllegalStateException("clone() called on " + 130 "non-cloneable object."); 131 } 132 } 133 134 /** 135 * Compares this feature with the supplied object. This returns 136 * true iff the object is an instance of {@link 137 * MBeanNotificationInfo}, {@link Object#equals()} returns true for 138 * a comparison of both the name and description of this 139 * notification with that of the specified object, and the two 140 * notification type arrays contain the same elements in the same 141 * order (but one may be longer than the other). 142 * 143 * @param obj the object to compare. 144 * @return true if the object is a {@link MBeanNotificationInfo} 145 * instance, 146 * <code>name.equals(object.getName())</code>, 147 * <code>description.equals(object.getDescription())</code> 148 * and the corresponding elements of the type arrays are 149 * equal. 150 */ 151 public boolean equals(Object obj) 152 { 153 if (obj instanceof MBeanNotificationInfo) 154 { 155 if (!(super.equals(obj))) 156 return false; 157 MBeanNotificationInfo o = (MBeanNotificationInfo) obj; 158 String[] oTypes = o.getNotifTypes(); 159 for (int a = 0; a < types.length; ++a) 160 { 161 if (a == oTypes.length) 162 return true; 163 if (!(types[a].equals(oTypes[a]))) 164 return false; 165 } 166 return true; 167 } 168 else 169 return false; 170 } 171 172 /** 173 * Returns the notification types that the management bean may emit. 174 * The notification types are strings using the dot notation 175 * familiar from Java property and package names. Changing the 176 * returned array does not affect the values retained by this 177 * instance. 178 * 179 * @return the notification types. 180 */ 181 public String[] getNotifTypes() 182 { 183 return types; 184 } 185 186 /** 187 * Returns the hashcode of the notification information as the sum 188 * of the hashcode of the superclass and the hashcode of the types 189 * array. 190 * 191 * @return the hashcode of the notification information. 192 */ 193 public int hashCode() 194 { 195 return super.hashCode() + Arrays.hashCode(types); 196 } 197 198 /** 199 * <p> 200 * Returns a textual representation of this instance. This 201 * is constructed using the class name 202 * (<code>javax.management.MBeanNotificationInfo</code>), 203 * the name and description of the notification and the 204 * contents of the array of types. 205 * </p> 206 * <p> 207 * As instances of this class are immutable, the return value 208 * is computed just once for each instance and reused 209 * throughout its life. 210 * </p> 211 * 212 * @return a @link{java.lang.String} instance representing 213 * the instance in textual form. 214 */ 215 public String toString() 216 { 217 if (string == null) 218 { 219 super.toString(); 220 string = string.substring(0, string.length() - 1) 221 + ",types=" + Arrays.toString(types) 222 + "]"; 223 } 224 return string; 225 } 226 227}