/*
* @(#)OpenMBeanInfoSupport.java 3.22 03/12/19
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.management.openmbean;
// java import
//
import java.io.Serializable;
import java.util.Arrays;
import java.util.HashSet;
// jmx import
//
import javax.management.MBeanInfo;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanConstructorInfo;
import javax.management.MBeanNotificationInfo;
/**
* The <tt>OpenMBeanInfoSupport</tt> class describes the management information of an <i>open MBean</i>:
* it is a subclass of {@link javax.management.MBeanInfo}, and it implements the {@link OpenMBeanInfo} interface.
* Note that an <i>open MBean</i> is recognized as such if its <tt>getMBeanInfo()</tt> method returns an instance of a class
* which implements the OpenMBeanInfo interface, typically <tt>OpenMBeanInfoSupport</tt>.
*
* @version 3.22 03/12/19
* @author Sun Microsystems, Inc.
*
* @since 1.5
* @since.unbundled JMX 1.1
*/
public class OpenMBeanInfoSupport
extends MBeanInfo
implements OpenMBeanInfo, Serializable {
/* Serial version */
static final long serialVersionUID = 4349395935420511492L;
private transient Integer myHashCode = null; // As this instance is immutable, these two values
private transient String myToString = null; // need only be calculated once.
/**
* Constructs an <tt>OpenMBeanInfoSupport</tt> instance,
* which describes a class of open MBeans with the specified
* <var>className</var>, <var>description</var>, <var>openAttributes</var>,
* <var>openConstructors</var> , <var>openOperations</var> and <var>notifications</var>.
* <p>
* The <var>openAttributes</var>, <var>openConstructors</var>,
* <var>openOperations</var> and <var>notifications</var>
* array parameters are internally copied, so that subsequent changes
* to the arrays referenced by these parameters have no effect on this instance.
* <p>
*
*
* @param className The fully qualified Java class name of
* the open MBean described by this <CODE>OpenMBeanInfoSupport</CODE> instance.
*
* @param description A human readable description of
* the open MBean described by this <CODE>OpenMBeanInfoSupport</CODE> instance.
*
* @param openAttributes The list of exposed attributes of the described open MBean;
* Must be an array of instances of a subclass of <tt>MBeanAttributeInfo</tt>,
* typically <tt>OpenMBeanAttributeInfoSupport</tt>.
*
* @param openConstructors The list of exposed public constructors of the described open MBean;
* Must be an array of instances of a subclass of <tt>MBeanConstructorInfo</tt>,
* typically <tt>OpenMBeanConstructorInfoSupport</tt>.
*
* @param openOperations The list of exposed operations of the described open MBean.
* Must be an array of instances of a subclass of <tt>MBeanOperationInfo</tt>,
* typically <tt>OpenMBeanOperationInfoSupport</tt>.
*
* @param notifications The list of notifications emitted by the described open MBean.
*
* @throws ArrayStoreException If <var>openAttributes</var>, <var>openConstructors</var> or <var>openOperations</var>
* is not an array of instances of a subclass of <tt>MBeanAttributeInfo</tt>,
* <tt>MBeanConstructorInfo</tt> or <tt>MBeanOperationInfo</tt> respectively.
*/
public OpenMBeanInfoSupport(String className,
String description,
OpenMBeanAttributeInfo[] openAttributes,
OpenMBeanConstructorInfo[] openConstructors,
OpenMBeanOperationInfo[] openOperations,
MBeanNotificationInfo[] notifications) {
super(className,
description,
( openAttributes == null ? null : attributesArrayCopyCast(openAttributes) ), // may throw an ArrayStoreException
( openConstructors == null ? null : constructorsArrayCopyCast(openConstructors) ), // may throw an ArrayStoreException
( openOperations == null ? null : operationsArrayCopyCast(openOperations) ), // may throw an ArrayStoreException
( notifications == null ? null : notificationsArrayCopy(notifications) ));
}
private static MBeanAttributeInfo[] attributesArrayCopyCast(OpenMBeanAttributeInfo[] src) throws ArrayStoreException {
MBeanAttributeInfo[] dst = new MBeanAttributeInfo[src.length];
System.arraycopy(src, 0, dst, 0, src.length); // may throw an ArrayStoreException
return dst;
}
private static MBeanConstructorInfo[] constructorsArrayCopyCast(OpenMBeanConstructorInfo[] src) throws ArrayStoreException {
MBeanConstructorInfo[] dst = new MBeanConstructorInfo[src.length];
System.arraycopy(src, 0, dst, 0, src.length); // may throw an ArrayStoreException
return dst;
}
private static MBeanOperationInfo[] operationsArrayCopyCast(OpenMBeanOperationInfo[] src) throws ArrayStoreException {
MBeanOperationInfo[] dst = new MBeanOperationInfo[src.length];
System.arraycopy(src, 0, dst, 0, src.length); // may throw an ArrayStoreException
return dst;
}
private static MBeanNotificationInfo[] notificationsArrayCopy(MBeanNotificationInfo[] src) {
MBeanNotificationInfo[] dst = new MBeanNotificationInfo[src.length];
System.arraycopy(src, 0, dst, 0, src.length);
return dst;
}
/* *** Commodity methods from java.lang.Object *** */
/**
* Compares the specified <var>obj</var> parameter with this <code>OpenMBeanInfoSupport</code> instance for equality.
* <p>
* Returns <tt>true</tt> if and only if all of the following statements are true:
* <ul>
* <li><var>obj</var> is non null,</li>
* <li><var>obj</var> also implements the <code>OpenMBeanInfo</code> interface,</li>
* <li>their class names are equal</li>
* <li>their infos on attributes, constructors, operations and notifications are equal</li>
* </ul>
* This ensures that this <tt>equals</tt> method works properly for <var>obj</var> parameters which are
* different implementations of the <code>OpenMBeanInfo</code> interface.
* <br>
* @param obj the object to be compared for equality with this <code>OpenMBeanInfoSupport</code> instance;
*
* @return <code>true</code> if the specified object is equal to this <code>OpenMBeanInfoSupport</code> instance.
*/
public boolean equals(Object obj) {
// if obj is null, return false
//
if (obj == null) {
return false;
}
// if obj is not a OpenMBeanInfo, return false
//
OpenMBeanInfo other;
try {
other = (OpenMBeanInfo) obj;
} catch (ClassCastException e) {
return false;
}
// Now, really test for equality between this OpenMBeanInfo implementation and the other:
//
// their MBean className should be equal
if ( ! this.getClassName().equals(other.getClassName()) ) {
return false;
}
// their infos on attributes should be equal (order not significant => equality between sets, not arrays or lists)
if ( ! new HashSet(Arrays.asList(this.getAttributes())).equals(new HashSet(Arrays.asList(other.getAttributes()))) ) {
return false;
}
// their infos on constructors should be equal (order not significant => equality between sets, not arrays or lists)
if ( ! new HashSet(Arrays.asList(this.getConstructors())).equals(new HashSet(Arrays.asList(other.getConstructors()))) ) {
return false;
}
// their infos on operations should be equal (order not significant => equality between sets, not arrays or lists)
if ( ! new HashSet(Arrays.asList(this.getOperations())).equals(new HashSet(Arrays.asList(other.getOperations()))) ) {
return false;
}
// their infos on notifications should be equal (order not significant => equality between sets, not arrays or lists)
if ( ! new HashSet(Arrays.asList(this.getNotifications())).equals(new HashSet(Arrays.asList(other.getNotifications()))) ) {
return false;
}
// All tests for equality were successfull
//
return true;
}
/**
* Returns the hash code value for this <code>OpenMBeanInfoSupport</code> instance.
* <p>
* The hash code of an <code>OpenMBeanInfoSupport</code> instance is the sum of the hash codes
* of all elements of information used in <code>equals</code> comparisons
* (ie: its class name, and its infos on attributes, constructors, operations and notifications,
* where the hashCode of each of these arrays is calculated by a call to
* <tt>new java.util.HashSet(java.util.Arrays.asList(this.getSignature)).hashCode()</tt>).
* <p>
* This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code>
* for any two <code>OpenMBeanInfoSupport</code> instances <code>t1</code> and <code>t2</code>,
* as required by the general contract of the method
* {@link Object#hashCode() Object.hashCode()}.
* <p>
* However, note that another instance of a class implementing the <code>OpenMBeanInfo</code> interface
* may be equal to this <code>OpenMBeanInfoSupport</code> instance as defined by {@link #equals(java.lang.Object)},
* but may have a different hash code if it is calculated differently.
* <p>
* As <code>OpenMBeanInfoSupport</code> instances are immutable, the hash code for this instance is calculated once,
* on the first call to <code>hashCode</code>, and then the same value is returned for subsequent calls.
*
* @return the hash code value for this <code>OpenMBeanInfoSupport</code> instance
*/
public int hashCode() {
// Calculate the hash code value if it has not yet been done (ie 1st call to hashCode())
//
if (myHashCode == null) {
int value = 0;
value += this.getClassName().hashCode();
value += new HashSet(Arrays.asList(this.getAttributes())).hashCode();
value += new HashSet(Arrays.asList(this.getConstructors())).hashCode();
value += new HashSet(Arrays.asList(this.getOperations())).hashCode();
value += new HashSet(Arrays.asList(this.getNotifications())).hashCode();
myHashCode = new Integer(value);
}
// return always the same hash code for this instance (immutable)
//
return myHashCode.intValue();
}
/**
* Returns a string representation of this <code>OpenMBeanInfoSupport</code> instance.
* <p>
* The string representation consists of the name of this class (ie <code>javax.management.openmbean.OpenMBeanInfoSupport</code>),
* the MBean class name,
* and the string representation of infos on attributes, constructors, operations and notifications of the described MBean.
* <p>
* As <code>OpenMBeanInfoSupport</code> instances are immutable,
* the string representation for this instance is calculated once,
* on the first call to <code>toString</code>, and then the same value is returned for subsequent calls.
*
* @return a string representation of this <code>OpenMBeanInfoSupport</code> instance
*/
public String toString() {
// Calculate the hash code value if it has not yet been done (ie 1st call to toString())
//
if (myToString == null) {
myToString = new StringBuffer()
.append(this.getClass().getName())
.append("(mbean_class_name=")
.append(this.getClassName())
.append(",attributes=")
.append(Arrays.asList(this.getAttributes()).toString())
.append(",constructors=")
.append(Arrays.asList(this.getConstructors()).toString())
.append(",operations=")
.append(Arrays.asList(this.getOperations()).toString())
.append(",notifications=")
.append(Arrays.asList(this.getNotifications()).toString())
.append(")")
.toString();
}
// return always the same string representation for this instance (immutable)
//
return myToString;
}
}
|