/* * Copyright (c) 2000, 2008, 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.openmbean;  // java import//import java.util.Arrays;import java.util.HashSet; import javax.management.Descriptor;import javax.management.MBeanAttributeInfo;import javax.management.MBeanConstructorInfo;import javax.management.MBeanInfo;import javax.management.MBeanNotificationInfo;import javax.management.MBeanOperationInfo; /** * The {@code OpenMBeanInfoSupport} 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 {@code getMBeanInfo()} method returns an * instance of a class which implements the OpenMBeanInfo interface, * typically {@code OpenMBeanInfoSupport}. * * * @since 1.5 */public class OpenMBeanInfoSupport    extends MBeanInfo    implements OpenMBeanInfo {     /* Serial version */    static final long serialVersionUID = 4349395935420511492L;     // As this instance is immutable, these two values    // need only be calculated once.    private transient Integer myHashCode = null;    private transient String  myToString = null;      /**     * <p>Constructs an {@code OpenMBeanInfoSupport} instance, which     * describes a class of open MBeans with the specified {@code     * className}, {@code description}, {@code openAttributes}, {@code     * openConstructors} , {@code openOperations} and {@code     * notifications}.</p>     *     * <p>The {@code openAttributes}, {@code openConstructors},     * {@code openOperations} and {@code notifications}     * 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 {@code MBeanAttributeInfo}, typically {@code     * OpenMBeanAttributeInfoSupport}.     *     * @param openConstructors The list of exposed public constructors     * of the described open MBean; Must be an array of instances of a     * subclass of {@code MBeanConstructorInfo}, typically {@code     * OpenMBeanConstructorInfoSupport}.     *     * @param openOperations The list of exposed operations of the     * described open MBean.  Must be an array of instances of a     * subclass of {@code MBeanOperationInfo}, typically {@code     * OpenMBeanOperationInfoSupport}.     *     * @param notifications The list of notifications emitted by the     * described open MBean.     *     * @throws ArrayStoreException If {@code openAttributes}, {@code     * openConstructors} or {@code openOperations} is not an array of     * instances of a subclass of {@code MBeanAttributeInfo}, {@code     * MBeanConstructorInfo} or {@code MBeanOperationInfo}     * respectively.     */    public OpenMBeanInfoSupport(String className,                                String description,                                OpenMBeanAttributeInfo[] openAttributes,                                OpenMBeanConstructorInfo[] openConstructors,                                OpenMBeanOperationInfo[] openOperations,                                MBeanNotificationInfo[] notifications) {        this(className, description,             openAttributes, openConstructors, openOperations, notifications,             (Descriptor) null);    }     /**     * <p>Constructs an {@code OpenMBeanInfoSupport} instance, which     * describes a class of open MBeans with the specified {@code     * className}, {@code description}, {@code openAttributes}, {@code     * openConstructors} , {@code openOperations}, {@code     * notifications}, and {@code descriptor}.</p>     *     * <p>The {@code openAttributes}, {@code openConstructors}, {@code     * openOperations} and {@code notifications} 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 {@code MBeanAttributeInfo}, typically {@code     * OpenMBeanAttributeInfoSupport}.     *     * @param openConstructors The list of exposed public constructors     * of the described open MBean; Must be an array of instances of a     * subclass of {@code MBeanConstructorInfo}, typically {@code     * OpenMBeanConstructorInfoSupport}.     *     * @param openOperations The list of exposed operations of the     * described open MBean.  Must be an array of instances of a     * subclass of {@code MBeanOperationInfo}, typically {@code     * OpenMBeanOperationInfoSupport}.     *     * @param notifications The list of notifications emitted by the     * described open MBean.     *     * @param descriptor The descriptor for the MBean.  This may be null     * which is equivalent to an empty descriptor.     *     * @throws ArrayStoreException If {@code openAttributes}, {@code     * openConstructors} or {@code openOperations} is not an array of     * instances of a subclass of {@code MBeanAttributeInfo}, {@code     * MBeanConstructorInfo} or {@code MBeanOperationInfo}     * respectively.     *     * @since 1.6     */    public OpenMBeanInfoSupport(String className,                                String description,                                OpenMBeanAttributeInfo[] openAttributes,                                OpenMBeanConstructorInfo[] openConstructors,                                OpenMBeanOperationInfo[] openOperations,                                MBeanNotificationInfo[] notifications,                                Descriptor descriptor) {        super(className,              description,              attributeArray(openAttributes),              constructorArray(openConstructors),              operationArray(openOperations),              (notifications == null) ? null : notifications.clone(),              descriptor);    }      private static MBeanAttributeInfo[]            attributeArray(OpenMBeanAttributeInfo[] src) {        if (src == null)            return null;        MBeanAttributeInfo[] dst = new MBeanAttributeInfo[src.length];        System.arraycopy(src, 0, dst, 0, src.length);        // may throw an ArrayStoreException        return dst;    }     private static MBeanConstructorInfo[]            constructorArray(OpenMBeanConstructorInfo[] src) {        if (src == null)            return null;        MBeanConstructorInfo[] dst = new MBeanConstructorInfo[src.length];        System.arraycopy(src, 0, dst, 0, src.length);        // may throw an ArrayStoreException        return dst;    }     private static MBeanOperationInfo[]            operationArray(OpenMBeanOperationInfo[] src) {        if (src == null)            return null;        MBeanOperationInfo[] dst = new MBeanOperationInfo[src.length];        System.arraycopy(src, 0, dst, 0, src.length);        return dst;    }       /* ***  Commodity methods from java.lang.Object  *** */      /**     * <p>Compares the specified {@code obj} parameter with this     * {@code OpenMBeanInfoSupport} instance for equality.</p>     *     * <p>Returns {@code true} if and only if all of the following     * statements are true:     *     * <ul>     * <li>{@code obj} is non null,</li>     * <li>{@code obj} also implements the {@code OpenMBeanInfo}     * 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 {@code equals} method works properly for     * {@code obj} parameters which are different implementations of     * the {@code OpenMBeanInfo} interface.     *     * @param obj the object to be compared for equality with this     * {@code OpenMBeanInfoSupport} instance;     *     * @return {@code true} if the specified object is equal to this     * {@code OpenMBeanInfoSupport} 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 (!sameArrayContents(this.getAttributes(), other.getAttributes()))            return false;         // their infos on constructors should be equal (order not        // significant => equality between sets, not arrays or lists)        if (!sameArrayContents(this.getConstructors(), other.getConstructors()))            return false;         // their infos on operations should be equal (order not        // significant => equality between sets, not arrays or lists)        if (!sameArrayContents(this.getOperations(), other.getOperations()))             return false;         // their infos on notifications should be equal (order not        // significant => equality between sets, not arrays or lists)        if (!sameArrayContents(this.getNotifications(), other.getNotifications()))            return false;         // All tests for equality were successful        //        return true;    }     private static <T> boolean sameArrayContents(T[] a1, T[] a2) {        return (new HashSet<T>(Arrays.asList(a1))                .equals(new HashSet<T>(Arrays.asList(a2))));    }     /**     * <p>Returns the hash code value for this {@code     * OpenMBeanInfoSupport} instance.</p>     *     * <p>The hash code of an {@code OpenMBeanInfoSupport} instance is     * the sum of the hash codes of all elements of information used     * in {@code equals} 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 {@code new     * java.util.HashSet(java.util.Arrays.asList(this.getSignature)).hashCode()}).</p>     *     * <p>This ensures that {@code t1.equals(t2)} implies that {@code     * t1.hashCode()==t2.hashCode()} for any two {@code     * OpenMBeanInfoSupport} instances {@code t1} and {@code t2}, as     * required by the general contract of the method {@link     * Object#hashCode() Object.hashCode()}.</p>     *     * <p>However, note that another instance of a class implementing     * the {@code OpenMBeanInfo} interface may be equal to this {@code     * OpenMBeanInfoSupport} instance as defined by {@link     * #equals(java.lang.Object)}, but may have a different hash code     * if it is calculated differently.</p>     *     * <p>As {@code OpenMBeanInfoSupport} instances are immutable, the     * hash code for this instance is calculated once, on the first     * call to {@code hashCode}, and then the same value is returned     * for subsequent calls.</p>     *     * @return the hash code value for this {@code     * OpenMBeanInfoSupport} 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 += arraySetHash(this.getAttributes());            value += arraySetHash(this.getConstructors());            value += arraySetHash(this.getOperations());            value += arraySetHash(this.getNotifications());            myHashCode = Integer.valueOf(value);        }         // return always the same hash code for this instance (immutable)        //        return myHashCode.intValue();    }     private static <T> int arraySetHash(T[] a) {        return new HashSet<T>(Arrays.asList(a)).hashCode();    }       /**     * <p>Returns a string representation of this {@code     * OpenMBeanInfoSupport} instance.</p>     *     * <p>The string representation consists of the name of this class     * (ie {@code javax.management.openmbean.OpenMBeanInfoSupport}),     * the MBean class name, the string representation of infos on     * attributes, constructors, operations and notifications of the     * described MBean and the string representation of the descriptor.</p>     *     * <p>As {@code OpenMBeanInfoSupport} instances are immutable, the     * string representation for this instance is calculated once, on     * the first call to {@code toString}, and then the same value is     * returned for subsequent calls.</p>     *     * @return a string representation of this {@code     * OpenMBeanInfoSupport} instance     */    public String toString() {         // Calculate the string value if it has not yet been done (ie        // 1st call to toString())        //        if (myToString == null) {            myToString = new StringBuilder()                .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(",descriptor=")                .append(this.getDescriptor())                .append(")")                .toString();        }         // return always the same string representation for this        // instance (immutable)        //        return myToString;    } }