1 /* 2 * Copyright (c) 2007, 2010, 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 26 27 package com.sun.org.glassfish.gmbal ; 28 29 import java.lang.annotation.Documented ; 30 import java.lang.annotation.Target ; 31 import java.lang.annotation.ElementType ; 32 import java.lang.annotation.Retention ; 33 import java.lang.annotation.RetentionPolicy ; 34 35 /** This annotation defines an attribute in either CompositeData (ManagedData) or 36 * an open MBean (ManagedObject). An attribute may be read/write (has a setter 37 * and a getter), read only (only has a getter), 38 * or write only (only has a setter) depending on the declared methods in the class. 39 * <p> 40 * A method defines a getter if it returns a non-void type and takes no argument types. 41 * Likewise a method defines a setter if it return void and takes exactly one 42 * argument. 43 * <p>An id is derived from a method name as follows: 44 * <ol> 45 * <li>If the method is a getter, and has a name of the form getXXX, the derived 46 * id is xXX (note the initial lower case change). 47 * <li>If the method is a getter with a boolean return type, and has a name of 48 * the form isXXX, the derived id is xXX 49 * <li>If the method is a setter, and has a name of the form setXXX, the 50 * detived id is xXX. 51 * <li>Otherwise the derived ID is the method name. 52 * </ol> 53 * <p> 54 * In certain cases, a field annotated with @ManagedAttribute 55 * may also represent a read-only attribute. 56 * The field must be final, and its type must be one of: 57 * <ol> 58 * <li>A primitive type (boolean, byte, short, char, int, long, float, double) 59 * <li>A primitive type wrapper (Boolean, Byte, Short, Character, Integer, 60 * Long, Float, Double) 61 * <li>A String 62 * <li>A BigDecimal or BigInteger 63 * <li>A java.util.Date 64 * <li>An ObjectName 65 * <li>An enum (which is translated to its ordinal name) 66 * </ol> 67 * Any such field can be accessed safely by multiple threads, because its value 68 * cannot change after an instance of the containing class has completed its 69 * constructor. Note that Date is not truly immutable (it should be!), but it's 70 * one of the Open MBean simple types, so it is included here. 71 */ 72 @Documented 73 @Target({ElementType.METHOD,ElementType.FIELD}) 74 @Retention(RetentionPolicy.RUNTIME) 75 public @interface ManagedAttribute { 76 /** The id of the attribute. Defaults to value derived from method name. 77 * @return The id (default ""). 78 */ 79 String id() default "" ; 80 }