/*
* Copyright (c) 1999, 2013, 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
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*/
package javax.management;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.util.Arrays;
import java.util.Objects;
/**
* <p>The {@code MBeanNotificationInfo} class is used to describe the
* characteristics of the different notification instances
* emitted by an MBean, for a given Java class of notification.
* If an MBean emits notifications that can be instances of different Java classes,
* then the metadata for that MBean should provide an {@code MBeanNotificationInfo}
* object for each of these notification Java classes.</p>
*
* <p>Instances of this class are immutable. Subclasses may be
* mutable but this is not recommended.</p>
*
* <p>This class extends {@code javax.management.MBeanFeatureInfo}
* and thus provides {@code name} and {@code description} fields.
* The {@code name} field should be the fully qualified Java class name of
* the notification objects described by this class.</p>
*
* <p>The {@code getNotifTypes} method returns an array of
* strings containing the notification types that the MBean may
* emit. The notification type is a dot-notation string which
* describes what the emitted notification is about, not the Java
* class of the notification. A single generic notification class can
* be used to send notifications of several types. All of these types
* are returned in the string array result of the
* {@code getNotifTypes} method.
*
* @since 1.5
*/
public class MBeanNotificationInfo extends MBeanFeatureInfo implements Cloneable {
/* Serial version */
static final long serialVersionUID = -3888371564530107064L;
private static final String[] NO_TYPES = new String[0];
static final MBeanNotificationInfo[] NO_NOTIFICATIONS =
new MBeanNotificationInfo[0];
/**
* @serial The different types of the notification.
*/
private String[] types;
/** @see MBeanInfo#arrayGettersSafe */
private final transient boolean arrayGettersSafe;
/**
* Constructs an {@code MBeanNotificationInfo} object.
*
* @param notifTypes The array of strings (in dot notation)
* containing the notification types that the MBean may emit.
* This may be null with the same effect as a zero-length array.
* @param name The fully qualified Java class name of the
* described notifications.
* @param description A human readable description of the data.
*/
public MBeanNotificationInfo(String[] notifTypes,
String name,
String description) {
this(notifTypes, name, description, null);
}
/**
* Constructs an {@code MBeanNotificationInfo} object.
*
* @param notifTypes The array of strings (in dot notation)
* containing the notification types that the MBean may emit.
* This may be null with the same effect as a zero-length array.
* @param name The fully qualified Java class name of the
* described notifications.
* @param description A human readable description of the data.
* @param descriptor The descriptor for the notifications. This may be null
* which is equivalent to an empty descriptor.
*
* @since 1.6
*/
public MBeanNotificationInfo(String[] notifTypes,
String name,
String description,
Descriptor descriptor) {
super(name, description, descriptor);
/* We do not validate the notifTypes, since the spec just says
they are dot-separated, not that they must look like Java
classes. E.g. the spec doesn't forbid "sun.prob.25" as a
notifType, though it doesn't explicitly allow it
either. */
this.types = (notifTypes != null && notifTypes.length > 0) ?
notifTypes.clone() : NO_TYPES;
this.arrayGettersSafe =
MBeanInfo.arrayGettersSafe(this.getClass(),
MBeanNotificationInfo.class);
}
/**
* Returns a shallow clone of this instance.
* The clone is obtained by simply calling {@code super.clone()},
* thus calling the default native shallow cloning mechanism
* implemented by {@code Object.clone()}.
* No deeper cloning of any internal field is made.
*/
public Object clone () {
try {
return super.clone() ;
} catch (CloneNotSupportedException e) {
// should not happen as this class is cloneable
return null;
}
}
/**
* Returns the array of strings (in dot notation) containing the
* notification types that the MBean may emit.
*
* @return the array of strings. Changing the returned array has no
* effect on this MBeanNotificationInfo.
*/
public String[] getNotifTypes() {
if (types.length == 0)
return NO_TYPES;
else
return types.clone();
}
private String[] fastGetNotifTypes() {
if (arrayGettersSafe)
return types;
else
return getNotifTypes();
}
public String toString() {
return
getClass().getName() + "[" +
"description=" + getDescription() + ", " +
"name=" + getName() + ", " +
"notifTypes=" + Arrays.asList(fastGetNotifTypes()) + ", " +
"descriptor=" + getDescriptor() +
"]";
}
/**
* Compare this MBeanNotificationInfo to another.
*
* @param o the object to compare to.
*
* @return true if and only if {@code o} is an MBeanNotificationInfo
* such that its {@link #getName()}, {@link #getDescription()},
* {@link #getDescriptor()},
* and {@link #getNotifTypes()} values are equal (not necessarily
* identical) to those of this MBeanNotificationInfo. Two
* notification type arrays are equal if their corresponding
* elements are equal. They are not equal if they have the same
* elements but in a different order.
*/
public boolean equals(Object o) {
if (o == this)
return true;
if (!(o instanceof MBeanNotificationInfo))
return false;
MBeanNotificationInfo p = (MBeanNotificationInfo) o;
return (Objects.equals(p.getName(), getName()) &&
Objects.equals(p.getDescription(), getDescription()) &&
Objects.equals(p.getDescriptor(), getDescriptor()) &&
Arrays.equals(p.fastGetNotifTypes(), fastGetNotifTypes()));
}
public int hashCode() {
int hash = getName().hashCode();
for (int i = 0; i < types.length; i++)
hash ^= types[i].hashCode();
return hash;
}
private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
ObjectInputStream.GetField gf = ois.readFields();
String[] t = (String[])gf.get("types", null);
types = (t != null && t.length != 0) ? t.clone() : NO_TYPES;
}
}