| /* |
| * Copyright (c) 1999, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.management; |
| |
| import java.io.IOException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.io.Serializable; |
| import java.io.StreamCorruptedException; |
| import java.util.Objects; |
| |
| /** |
| * <p>Provides general information for an MBean descriptor object. |
| * The feature described can be an attribute, an operation, a |
| * parameter, or a notification. Instances of this class are |
| * immutable. Subclasses may be mutable but this is not |
| * recommended.</p> |
| * |
| * @since 1.5 |
| */ |
| public class MBeanFeatureInfo implements Serializable, DescriptorRead { |
| |
| |
| /* Serial version */ |
| static final long serialVersionUID = 3952882688968447265L; |
| |
| /** |
| * The name of the feature. It is recommended that subclasses call |
| * {@link #getName} rather than reading this field, and that they |
| * not change it. |
| * |
| * @serial The name of the feature. |
| */ |
| protected String name; |
| |
| /** |
| * The human-readable description of the feature. It is |
| * recommended that subclasses call {@link #getDescription} rather |
| * than reading this field, and that they not change it. |
| * |
| * @serial The human-readable description of the feature. |
| */ |
| protected String description; |
| |
| /** |
| * @serial The Descriptor for this MBeanFeatureInfo. This field |
| * can be null, which is equivalent to an empty Descriptor. |
| */ |
| private transient Descriptor descriptor; |
| |
| |
| /** |
| * Constructs an <CODE>MBeanFeatureInfo</CODE> object. This |
| * constructor is equivalent to {@code MBeanFeatureInfo(name, |
| * description, (Descriptor) null}. |
| * |
| * @param name The name of the feature. |
| * @param description A human readable description of the feature. |
| */ |
| public MBeanFeatureInfo(String name, String description) { |
| this(name, description, null); |
| } |
| |
| /** |
| * Constructs an <CODE>MBeanFeatureInfo</CODE> object. |
| * |
| * @param name The name of the feature. |
| * @param description A human readable description of the feature. |
| * @param descriptor The descriptor for the feature. This may be null |
| * which is equivalent to an empty descriptor. |
| * |
| * @since 1.6 |
| */ |
| public MBeanFeatureInfo(String name, String description, |
| Descriptor descriptor) { |
| this.name = name; |
| this.description = description; |
| this.descriptor = descriptor; |
| } |
| |
| /** |
| * Returns the name of the feature. |
| * |
| * @return the name of the feature. |
| */ |
| public String getName() { |
| return name; |
| } |
| |
| /** |
| * Returns the human-readable description of the feature. |
| * |
| * @return the human-readable description of the feature. |
| */ |
| public String getDescription() { |
| return description; |
| } |
| |
| /** |
| * Returns the descriptor for the feature. Changing the returned value |
| * will have no affect on the original descriptor. |
| * |
| * @return a descriptor that is either immutable or a copy of the original. |
| * |
| * @since 1.6 |
| */ |
| public Descriptor getDescriptor() { |
| return (Descriptor) ImmutableDescriptor.nonNullDescriptor(descriptor).clone(); |
| } |
| |
| /** |
| * Compare this MBeanFeatureInfo to another. |
| * |
| * @param o the object to compare to. |
| * |
| * @return true if and only if <code>o</code> is an MBeanFeatureInfo such |
| * that its {@link #getName()}, {@link #getDescription()}, and |
| * {@link #getDescriptor()} |
| * values are equal (not necessarily identical) to those of this |
| * MBeanFeatureInfo. |
| */ |
| public boolean equals(Object o) { |
| if (o == this) |
| return true; |
| if (!(o instanceof MBeanFeatureInfo)) |
| return false; |
| MBeanFeatureInfo p = (MBeanFeatureInfo) o; |
| return (Objects.equals(p.getName(), getName()) && |
| Objects.equals(p.getDescription(), getDescription()) && |
| Objects.equals(p.getDescriptor(), getDescriptor())); |
| } |
| |
| public int hashCode() { |
| return getName().hashCode() ^ getDescription().hashCode() ^ |
| getDescriptor().hashCode(); |
| } |
| |
| /** |
| * Serializes an {@link MBeanFeatureInfo} to an {@link ObjectOutputStream}. |
| * @serialData |
| * For compatibility reasons, an object of this class is serialized as follows. |
| * <p> |
| * The method {@link ObjectOutputStream#defaultWriteObject defaultWriteObject()} |
| * is called first to serialize the object except the field {@code descriptor} |
| * which is declared as transient. The field {@code descriptor} is serialized |
| * as follows: |
| * <ul> |
| * <li>If {@code descriptor} is an instance of the class |
| * {@link ImmutableDescriptor}, the method {@link ObjectOutputStream#write |
| * write(int val)} is called to write a byte with the value {@code 1}, |
| * then the method {@link ObjectOutputStream#writeObject writeObject(Object obj)} |
| * is called twice to serialize the field names and the field values of the |
| * {@code descriptor}, respectively as a {@code String[]} and an |
| * {@code Object[]};</li> |
| * <li>Otherwise, the method {@link ObjectOutputStream#write write(int val)} |
| * is called to write a byte with the value {@code 0}, then the method |
| * {@link ObjectOutputStream#writeObject writeObject(Object obj)} is called |
| * to serialize directly the field {@code descriptor}. |
| * </ul> |
| * |
| * @since 1.6 |
| */ |
| private void writeObject(ObjectOutputStream out) throws IOException { |
| out.defaultWriteObject(); |
| |
| if (descriptor != null && |
| descriptor.getClass() == ImmutableDescriptor.class) { |
| |
| out.write(1); |
| |
| final String[] names = descriptor.getFieldNames(); |
| |
| out.writeObject(names); |
| out.writeObject(descriptor.getFieldValues(names)); |
| } else { |
| out.write(0); |
| |
| out.writeObject(descriptor); |
| } |
| } |
| |
| /** |
| * Deserializes an {@link MBeanFeatureInfo} from an {@link ObjectInputStream}. |
| * @serialData |
| * For compatibility reasons, an object of this class is deserialized as follows. |
| * <p> |
| * The method {@link ObjectInputStream#defaultReadObject defaultReadObject()} |
| * is called first to deserialize the object except the field |
| * {@code descriptor}, which is not serialized in the default way. Then the method |
| * {@link ObjectInputStream#read read()} is called to read a byte, the field |
| * {@code descriptor} is deserialized according to the value of the byte value: |
| * <ul> |
| * <li>1. The method {@link ObjectInputStream#readObject readObject()} |
| * is called twice to obtain the field names (a {@code String[]}) and |
| * the field values (a {@code Object[]}) of the {@code descriptor}. |
| * The two obtained values then are used to construct |
| * an {@link ImmutableDescriptor} instance for the field |
| * {@code descriptor};</li> |
| * <li>0. The value for the field {@code descriptor} is obtained directly |
| * by calling the method {@link ObjectInputStream#readObject readObject()}. |
| * If the obtained value is null, the field {@code descriptor} is set to |
| * {@link ImmutableDescriptor#EMPTY_DESCRIPTOR EMPTY_DESCRIPTOR};</li> |
| * <li>-1. This means that there is no byte to read and that the object is from |
| * an earlier version of the JMX API. The field {@code descriptor} is set |
| * to {@link ImmutableDescriptor#EMPTY_DESCRIPTOR EMPTY_DESCRIPTOR}</li> |
| * <li>Any other value. A {@link StreamCorruptedException} is thrown.</li> |
| * </ul> |
| * |
| * @since 1.6 |
| */ |
| private void readObject(ObjectInputStream in) |
| throws IOException, ClassNotFoundException { |
| |
| in.defaultReadObject(); |
| |
| switch (in.read()) { |
| case 1: |
| final String[] names = (String[])in.readObject(); |
| |
| final Object[] values = (Object[]) in.readObject(); |
| descriptor = (names.length == 0) ? |
| ImmutableDescriptor.EMPTY_DESCRIPTOR : |
| new ImmutableDescriptor(names, values); |
| |
| break; |
| case 0: |
| descriptor = (Descriptor)in.readObject(); |
| |
| if (descriptor == null) { |
| descriptor = ImmutableDescriptor.EMPTY_DESCRIPTOR; |
| } |
| |
| break; |
| case -1: // from an earlier version of the JMX API |
| descriptor = ImmutableDescriptor.EMPTY_DESCRIPTOR; |
| |
| break; |
| default: |
| throw new StreamCorruptedException("Got unexpected byte."); |
| } |
| } |
| } |