author | uvangapally |
Tue, 01 Aug 2017 10:33:47 +0530 | |
changeset 46050 | f51c14dc540f |
parent 25859 | 3317bb8137f4 |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package javax.management.openmbean; |
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// java import |
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// |
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import java.util.Arrays; |
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import java.util.HashSet; |
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import java.util.Objects; |
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import javax.management.Descriptor; |
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import javax.management.MBeanAttributeInfo; |
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import javax.management.MBeanConstructorInfo; |
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import javax.management.MBeanInfo; |
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import javax.management.MBeanNotificationInfo; |
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import javax.management.MBeanOperationInfo; |
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/** |
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* The {@code OpenMBeanInfoSupport} class describes the management |
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* information of an <i>open MBean</i>: it is a subclass of {@link |
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* javax.management.MBeanInfo}, and it implements the {@link |
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* OpenMBeanInfo} interface. Note that an <i>open MBean</i> is |
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* recognized as such if its {@code getMBeanInfo()} method returns an |
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* instance of a class which implements the OpenMBeanInfo interface, |
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* typically {@code OpenMBeanInfoSupport}. |
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* |
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* |
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* @since 1.5 |
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*/ |
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public class OpenMBeanInfoSupport |
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extends MBeanInfo |
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implements OpenMBeanInfo { |
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/* Serial version */ |
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static final long serialVersionUID = 4349395935420511492L; |
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// As this instance is immutable, these two values |
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// need only be calculated once. |
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private transient Integer myHashCode = null; |
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private transient String myToString = null; |
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/** |
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* <p>Constructs an {@code OpenMBeanInfoSupport} instance, which |
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* describes a class of open MBeans with the specified {@code |
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* className}, {@code description}, {@code openAttributes}, {@code |
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* openConstructors} , {@code openOperations} and {@code |
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* notifications}.</p> |
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* |
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* <p>The {@code openAttributes}, {@code openConstructors}, |
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* {@code openOperations} and {@code notifications} |
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* array parameters are internally copied, so that subsequent changes |
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* to the arrays referenced by these parameters have no effect on this |
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* instance.</p> |
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* |
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* @param className The fully qualified Java class name of the |
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* open MBean described by this <CODE>OpenMBeanInfoSupport</CODE> |
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* instance. |
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* |
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* @param description A human readable description of the open |
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* MBean described by this <CODE>OpenMBeanInfoSupport</CODE> |
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* instance. |
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* |
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* @param openAttributes The list of exposed attributes of the |
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* described open MBean; Must be an array of instances of a |
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* subclass of {@code MBeanAttributeInfo}, typically {@code |
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* OpenMBeanAttributeInfoSupport}. |
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* |
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* @param openConstructors The list of exposed public constructors |
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* of the described open MBean; Must be an array of instances of a |
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* subclass of {@code MBeanConstructorInfo}, typically {@code |
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* OpenMBeanConstructorInfoSupport}. |
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* |
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* @param openOperations The list of exposed operations of the |
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* described open MBean. Must be an array of instances of a |
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* subclass of {@code MBeanOperationInfo}, typically {@code |
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* OpenMBeanOperationInfoSupport}. |
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* |
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* @param notifications The list of notifications emitted by the |
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* described open MBean. |
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* |
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* @throws ArrayStoreException If {@code openAttributes}, {@code |
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* openConstructors} or {@code openOperations} is not an array of |
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* instances of a subclass of {@code MBeanAttributeInfo}, {@code |
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* MBeanConstructorInfo} or {@code MBeanOperationInfo} |
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* respectively. |
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*/ |
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public OpenMBeanInfoSupport(String className, |
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String description, |
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OpenMBeanAttributeInfo[] openAttributes, |
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OpenMBeanConstructorInfo[] openConstructors, |
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OpenMBeanOperationInfo[] openOperations, |
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MBeanNotificationInfo[] notifications) { |
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this(className, description, |
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openAttributes, openConstructors, openOperations, notifications, |
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(Descriptor) null); |
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} |
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/** |
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* <p>Constructs an {@code OpenMBeanInfoSupport} instance, which |
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* describes a class of open MBeans with the specified {@code |
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* className}, {@code description}, {@code openAttributes}, {@code |
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* openConstructors} , {@code openOperations}, {@code |
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* notifications}, and {@code descriptor}.</p> |
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* |
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* <p>The {@code openAttributes}, {@code openConstructors}, {@code |
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* openOperations} and {@code notifications} array parameters are |
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* internally copied, so that subsequent changes to the arrays |
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* referenced by these parameters have no effect on this |
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* instance.</p> |
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* |
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* @param className The fully qualified Java class name of the |
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* open MBean described by this <CODE>OpenMBeanInfoSupport</CODE> |
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* instance. |
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* |
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* @param description A human readable description of the open |
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* MBean described by this <CODE>OpenMBeanInfoSupport</CODE> |
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* instance. |
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* |
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* @param openAttributes The list of exposed attributes of the |
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* described open MBean; Must be an array of instances of a |
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* subclass of {@code MBeanAttributeInfo}, typically {@code |
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* OpenMBeanAttributeInfoSupport}. |
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* |
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* @param openConstructors The list of exposed public constructors |
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* of the described open MBean; Must be an array of instances of a |
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* subclass of {@code MBeanConstructorInfo}, typically {@code |
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* OpenMBeanConstructorInfoSupport}. |
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* |
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* @param openOperations The list of exposed operations of the |
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* described open MBean. Must be an array of instances of a |
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* subclass of {@code MBeanOperationInfo}, typically {@code |
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* OpenMBeanOperationInfoSupport}. |
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* |
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* @param notifications The list of notifications emitted by the |
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* described open MBean. |
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* |
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* @param descriptor The descriptor for the MBean. This may be null |
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* which is equivalent to an empty descriptor. |
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* |
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* @throws ArrayStoreException If {@code openAttributes}, {@code |
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* openConstructors} or {@code openOperations} is not an array of |
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* instances of a subclass of {@code MBeanAttributeInfo}, {@code |
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* MBeanConstructorInfo} or {@code MBeanOperationInfo} |
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* respectively. |
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* |
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* @since 1.6 |
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*/ |
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public OpenMBeanInfoSupport(String className, |
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String description, |
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OpenMBeanAttributeInfo[] openAttributes, |
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OpenMBeanConstructorInfo[] openConstructors, |
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OpenMBeanOperationInfo[] openOperations, |
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MBeanNotificationInfo[] notifications, |
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Descriptor descriptor) { |
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super(className, |
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description, |
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attributeArray(openAttributes), |
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constructorArray(openConstructors), |
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operationArray(openOperations), |
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(notifications == null) ? null : notifications.clone(), |
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descriptor); |
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} |
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private static MBeanAttributeInfo[] |
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attributeArray(OpenMBeanAttributeInfo[] src) { |
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if (src == null) |
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return null; |
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MBeanAttributeInfo[] dst = new MBeanAttributeInfo[src.length]; |
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System.arraycopy(src, 0, dst, 0, src.length); |
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// may throw an ArrayStoreException |
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return dst; |
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} |
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private static MBeanConstructorInfo[] |
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constructorArray(OpenMBeanConstructorInfo[] src) { |
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if (src == null) |
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return null; |
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MBeanConstructorInfo[] dst = new MBeanConstructorInfo[src.length]; |
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System.arraycopy(src, 0, dst, 0, src.length); |
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// may throw an ArrayStoreException |
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return dst; |
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} |
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private static MBeanOperationInfo[] |
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operationArray(OpenMBeanOperationInfo[] src) { |
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if (src == null) |
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return null; |
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MBeanOperationInfo[] dst = new MBeanOperationInfo[src.length]; |
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System.arraycopy(src, 0, dst, 0, src.length); |
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return dst; |
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} |
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/* *** Commodity methods from java.lang.Object *** */ |
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/** |
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* <p>Compares the specified {@code obj} parameter with this |
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* {@code OpenMBeanInfoSupport} instance for equality.</p> |
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* |
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* <p>Returns {@code true} if and only if all of the following |
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* statements are true: |
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* |
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* <ul> |
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* <li>{@code obj} is non null,</li> |
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* <li>{@code obj} also implements the {@code OpenMBeanInfo} |
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* interface,</li> |
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* <li>their class names are equal</li> |
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* <li>their infos on attributes, constructors, operations and |
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* notifications are equal</li> |
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* </ul> |
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* |
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* This ensures that this {@code equals} method works properly for |
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* {@code obj} parameters which are different implementations of |
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* the {@code OpenMBeanInfo} interface. |
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* |
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* @param obj the object to be compared for equality with this |
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* {@code OpenMBeanInfoSupport} instance; |
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* |
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* @return {@code true} if the specified object is equal to this |
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* {@code OpenMBeanInfoSupport} instance. |
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*/ |
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public boolean equals(Object obj) { |
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// if obj is null, return false |
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// |
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if (obj == null) { |
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return false; |
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} |
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// if obj is not a OpenMBeanInfo, return false |
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// |
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OpenMBeanInfo other; |
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try { |
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other = (OpenMBeanInfo) obj; |
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} catch (ClassCastException e) { |
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return false; |
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} |
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// Now, really test for equality between this OpenMBeanInfo |
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// implementation and the other: |
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// |
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// their MBean className should be equal |
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if (!Objects.equals(this.getClassName(), other.getClassName())) { |
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return false; |
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} |
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// their infos on attributes should be equal (order not |
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// significant => equality between sets, not arrays or lists) |
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if (!sameArrayContents(this.getAttributes(), other.getAttributes())) |
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return false; |
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// their infos on constructors should be equal (order not |
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// significant => equality between sets, not arrays or lists) |
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if (!sameArrayContents(this.getConstructors(), other.getConstructors())) |
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return false; |
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// their infos on operations should be equal (order not |
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// significant => equality between sets, not arrays or lists) |
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if (!sameArrayContents(this.getOperations(), other.getOperations())) |
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return false; |
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// their infos on notifications should be equal (order not |
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// significant => equality between sets, not arrays or lists) |
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if (!sameArrayContents(this.getNotifications(), other.getNotifications())) |
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return false; |
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// All tests for equality were successful |
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// |
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return true; |
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} |
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private static <T> boolean sameArrayContents(T[] a1, T[] a2) { |
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return (new HashSet<T>(Arrays.asList(a1)) |
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.equals(new HashSet<T>(Arrays.asList(a2)))); |
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} |
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/** |
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* <p>Returns the hash code value for this {@code |
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* OpenMBeanInfoSupport} instance.</p> |
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* |
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* <p>The hash code of an {@code OpenMBeanInfoSupport} instance is |
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* the sum of the hash codes of all elements of information used |
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* in {@code equals} comparisons (ie: its class name, and its |
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* infos on attributes, constructors, operations and |
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* notifications, where the hashCode of each of these arrays is |
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* calculated by a call to {@code new |
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* java.util.HashSet(java.util.Arrays.asList(this.getSignature)).hashCode()}).</p> |
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* |
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* <p>This ensures that {@code t1.equals(t2)} implies that {@code |
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* t1.hashCode()==t2.hashCode()} for any two {@code |
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* OpenMBeanInfoSupport} instances {@code t1} and {@code t2}, as |
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* required by the general contract of the method {@link |
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* Object#hashCode() Object.hashCode()}.</p> |
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* |
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* <p>However, note that another instance of a class implementing |
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* the {@code OpenMBeanInfo} interface may be equal to this {@code |
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* OpenMBeanInfoSupport} instance as defined by {@link |
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* #equals(java.lang.Object)}, but may have a different hash code |
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* if it is calculated differently.</p> |
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* |
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* <p>As {@code OpenMBeanInfoSupport} instances are immutable, the |
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* hash code for this instance is calculated once, on the first |
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* call to {@code hashCode}, and then the same value is returned |
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* for subsequent calls.</p> |
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* |
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* @return the hash code value for this {@code |
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* OpenMBeanInfoSupport} instance |
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*/ |
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public int hashCode() { |
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// Calculate the hash code value if it has not yet been done |
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// (ie 1st call to hashCode()) |
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// |
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if (myHashCode == null) { |
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int value = 0; |
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if (this.getClassName() != null) { |
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value += this.getClassName().hashCode(); |
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} |
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value += arraySetHash(this.getAttributes()); |
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value += arraySetHash(this.getConstructors()); |
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value += arraySetHash(this.getOperations()); |
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value += arraySetHash(this.getNotifications()); |
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myHashCode = Integer.valueOf(value); |
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} |
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// return always the same hash code for this instance (immutable) |
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// |
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return myHashCode.intValue(); |
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} |
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private static <T> int arraySetHash(T[] a) { |
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return new HashSet<T>(Arrays.asList(a)).hashCode(); |
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} |
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/** |
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* <p>Returns a string representation of this {@code |
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* OpenMBeanInfoSupport} instance.</p> |
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* |
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* <p>The string representation consists of the name of this class |
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* (ie {@code javax.management.openmbean.OpenMBeanInfoSupport}), |
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* the MBean class name, the string representation of infos on |
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* attributes, constructors, operations and notifications of the |
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* described MBean and the string representation of the descriptor.</p> |
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* |
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* <p>As {@code OpenMBeanInfoSupport} instances are immutable, the |
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* string representation for this instance is calculated once, on |
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* the first call to {@code toString}, and then the same value is |
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* returned for subsequent calls.</p> |
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* |
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* @return a string representation of this {@code |
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* OpenMBeanInfoSupport} instance |
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*/ |
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public String toString() { |
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// Calculate the string value if it has not yet been done (ie |
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// 1st call to toString()) |
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// |
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if (myToString == null) { |
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myToString = new StringBuilder() |
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.append(this.getClass().getName()) |
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.append("(mbean_class_name=") |
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.append(this.getClassName()) |
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.append(",attributes=") |
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.append(Arrays.asList(this.getAttributes()).toString()) |
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.append(",constructors=") |
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.append(Arrays.asList(this.getConstructors()).toString()) |
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.append(",operations=") |
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.append(Arrays.asList(this.getOperations()).toString()) |
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.append(",notifications=") |
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.append(Arrays.asList(this.getNotifications()).toString()) |
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.append(",descriptor=") |
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.append(this.getDescriptor()) |
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.append(")") |
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.toString(); |
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} |
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// return always the same string representation for this |
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// instance (immutable) |
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412 |
// |
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413 |
return myToString; |
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} |
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} |