java/15 : java.management/javax/management/openmbean/OpenMBeanConstructorInfoSupport.java

OpenMBeanConstructorInfoSupport
https://openjdk.java.net/
GPLv2 + Classpath Exception
/*
 * 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 javax.management.Descriptor;
import javax.management.MBeanConstructorInfo;
import javax.management.MBeanParameterInfo;


Describes a constructor of an Open MBean.
Since: 1.5/**
 * Describes a constructor of an Open MBean.
 *
 *
 * @since 1.5
 */
public class OpenMBeanConstructorInfoSupport
    extends MBeanConstructorInfo
    implements OpenMBeanConstructorInfo {

    /* Serial version */
    static final long serialVersionUID = -4400441579007477003L;


    // As this instance is immutable,
    // these two values need only be calculated once.
    private transient Integer myHashCode = null;
    private transient String  myToString = null;

    Constructs an OpenMBeanConstructorInfoSupport instance, which describes the constructor of a class of open MBeans with the specified name, description and signature.
The signature array parameter is internally copied, so that subsequent changes to the array referenced by 
signature have no effect on this instance.
Params: name – cannot be a null or empty string.
description – cannot be a null or empty string.
signature – can be null or empty if there are no
parameters to describe.
Throws: IllegalArgumentException – if name or 
description are null or empty string.
ArrayStoreException – If signature is not an array of instances of a subclass of MBeanParameterInfo./**
     * <p>Constructs an {@code OpenMBeanConstructorInfoSupport}
     * instance, which describes the constructor of a class of open
     * MBeans with the specified {@code name}, {@code description} and
     * {@code signature}.</p>
     *
     * <p>The {@code signature} array parameter is internally copied,
     * so that subsequent changes to the array referenced by {@code
     * signature} have no effect on this instance.</p>
     *
     * @param name cannot be a null or empty string.
     *
     * @param description cannot be a null or empty string.
     *
     * @param signature can be null or empty if there are no
     * parameters to describe.
     *
     * @throws IllegalArgumentException if {@code name} or {@code
     * description} are null or empty string.
     *
     * @throws ArrayStoreException If {@code signature} is not an
     * array of instances of a subclass of {@code MBeanParameterInfo}.
     */
    public OpenMBeanConstructorInfoSupport(String name,
                                           String description,
                                           OpenMBeanParameterInfo[] signature) {
        this(name, description, signature, (Descriptor) null);
    }

    Constructs an OpenMBeanConstructorInfoSupport instance, which describes the constructor of a class of open MBeans with the specified name, description, signature, and descriptor.
The signature array parameter is internally copied, so that subsequent changes to the array referenced by 
signature have no effect on this instance.
Params: name – cannot be a null or empty string.
description – cannot be a null or empty string.
signature – can be null or empty if there are no
parameters to describe.
descriptor – The descriptor for the constructor.  This may
be null which is equivalent to an empty descriptor.
Throws: IllegalArgumentException – if name or 
description are null or empty string.
ArrayStoreException – If signature is not an array of instances of a subclass of MBeanParameterInfo.
Since: 1.6/**
     * <p>Constructs an {@code OpenMBeanConstructorInfoSupport}
     * instance, which describes the constructor of a class of open
     * MBeans with the specified {@code name}, {@code description},
     * {@code signature}, and {@code descriptor}.</p>
     *
     * <p>The {@code signature} array parameter is internally copied,
     * so that subsequent changes to the array referenced by {@code
     * signature} have no effect on this instance.</p>
     *
     * @param name cannot be a null or empty string.
     *
     * @param description cannot be a null or empty string.
     *
     * @param signature can be null or empty if there are no
     * parameters to describe.
     *
     * @param descriptor The descriptor for the constructor.  This may
     * be null which is equivalent to an empty descriptor.
     *
     * @throws IllegalArgumentException if {@code name} or {@code
     * description} are null or empty string.
     *
     * @throws ArrayStoreException If {@code signature} is not an
     * array of instances of a subclass of {@code MBeanParameterInfo}.
     *
     * @since 1.6
     */
    public OpenMBeanConstructorInfoSupport(String name,
                                           String description,
                                           OpenMBeanParameterInfo[] signature,
                                           Descriptor descriptor) {
        super(name,
              description,
              arrayCopyCast(signature), // may throw an ArrayStoreException
              descriptor);

        // check parameters that should not be null or empty
        // (unfortunately it is not done in superclass :-( ! )
        //
        if (name == null || name.trim().isEmpty()) {
            throw new IllegalArgumentException("Argument name cannot be " +
                                               "null or empty");
        }
        if (description == null || description.trim().isEmpty()) {
            throw new IllegalArgumentException("Argument description cannot " +
                                               "be null or empty");
        }

    }

    private static MBeanParameterInfo[]
            arrayCopyCast(OpenMBeanParameterInfo[] src) {
        if (src == null)
            return null;

        MBeanParameterInfo[] dst = new MBeanParameterInfo[src.length];
        System.arraycopy(src, 0, dst, 0, src.length);
        // may throw an ArrayStoreException
        return dst;
    }


    /* ***  Commodity methods from java.lang.Object  *** */


    Compares the specified obj parameter with this OpenMBeanConstructorInfoSupport instance for equality.
Returns true if and only if all of the following statements are true: 

obj is non null,
obj also implements the 
OpenMBeanConstructorInfo interface,
their names are equal
their signatures are equal.
 This ensures that this equals method works properly for obj parameters which are different implementations of the OpenMBeanConstructorInfo interface. 
Params: obj – the object to be compared for equality with this OpenMBeanConstructorInfoSupport instance;
Returns: true if the specified object is equal to this OpenMBeanConstructorInfoSupport instance./**
     * <p>Compares the specified {@code obj} parameter with this
     * {@code OpenMBeanConstructorInfoSupport} 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
     * OpenMBeanConstructorInfo} interface,</li>
     * <li>their names are equal</li>
     * <li>their signatures are equal.</li>
     * </ul>
     *
     * This ensures that this {@code equals} method works properly for
     * {@code obj} parameters which are different implementations of
     * the {@code OpenMBeanConstructorInfo} interface.
     *
     * @param obj the object to be compared for equality with this
     * {@code OpenMBeanConstructorInfoSupport} instance;
     *
     * @return {@code true} if the specified object is equal to this
     * {@code OpenMBeanConstructorInfoSupport} instance.
     */
    public boolean equals(Object obj) {

        // if obj is null, return false
        //
        if (obj == null) {
            return false;
        }

        // if obj is not a OpenMBeanConstructorInfo, return false
        //
        OpenMBeanConstructorInfo other;
        try {
            other = (OpenMBeanConstructorInfo) obj;
        } catch (ClassCastException e) {
            return false;
        }

        // Now, really test for equality between this
        // OpenMBeanConstructorInfo implementation and the other:
        //

        // their Name should be equal
        if ( ! this.getName().equals(other.getName()) ) {
            return false;
        }

        // their Signatures should be equal
        if ( ! Arrays.equals(this.getSignature(), other.getSignature()) ) {
            return false;
        }

        // All tests for equality were successfull
        //
        return true;
    }

    Returns the hash code value for this 
OpenMBeanConstructorInfoSupport instance.
The hash code of an OpenMBeanConstructorInfoSupport instance is the sum of the hash codes of all elements of information used in equals comparisons (ie: its name and signature, where the signature hashCode is calculated by a call to 
java.util.Arrays.asList(this.getSignature).hashCode()).
This ensures that t1.equals(t2) implies that 
t1.hashCode()==t2.hashCode() for any two 
OpenMBeanConstructorInfoSupport instances t1 and t2, as required by the general contract of the method Object.hashCode().
However, note that another instance of a class implementing the OpenMBeanConstructorInfo interface may be equal to this OpenMBeanConstructorInfoSupport instance as defined by equals(Object), but may have a different hash code if it is calculated differently.
As OpenMBeanConstructorInfoSupport instances are immutable, the hash code for this instance is calculated once, on the first call to hashCode, and then the same value is returned for subsequent calls.
Returns: the hash code value for this 
OpenMBeanConstructorInfoSupport instance/**
     * <p>Returns the hash code value for this {@code
     * OpenMBeanConstructorInfoSupport} instance.</p>
     *
     * <p>The hash code of an {@code OpenMBeanConstructorInfoSupport}
     * instance is the sum of the hash codes of all elements of
     * information used in {@code equals} comparisons (ie: its name
     * and signature, where the signature hashCode is calculated by a
     * call to {@code
     * 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
     * OpenMBeanConstructorInfoSupport} 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 OpenMBeanConstructorInfo} interface may be equal to
     * this {@code OpenMBeanConstructorInfoSupport} 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 OpenMBeanConstructorInfoSupport} 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
     * OpenMBeanConstructorInfoSupport} 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.getName().hashCode();
            value += Arrays.asList(this.getSignature()).hashCode();
            myHashCode = Integer.valueOf(value);
        }

        // return always the same hash code for this instance (immutable)
        //
        return myHashCode.intValue();
    }

    Returns a string representation of this 
OpenMBeanConstructorInfoSupport instance.
The string representation consists of the name of this class (ie 
javax.management.openmbean.OpenMBeanConstructorInfoSupport), the name and signature of the described constructor and the string representation of its descriptor.
As OpenMBeanConstructorInfoSupport instances are immutable, the string representation for this instance is calculated once, on the first call to toString, and then the same value is returned for subsequent calls.
Returns: a string representation of this 
OpenMBeanConstructorInfoSupport instance/**
     * <p>Returns a string representation of this {@code
     * OpenMBeanConstructorInfoSupport} instance.</p>
     *
     * <p>The string representation consists of the name of this class
     * (ie {@code
     * javax.management.openmbean.OpenMBeanConstructorInfoSupport}),
     * the name and signature of the described constructor and the
     * string representation of its descriptor.</p>
     *
     * <p>As {@code OpenMBeanConstructorInfoSupport} 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
     * OpenMBeanConstructorInfoSupport} 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("(name=")
                .append(this.getName())
                .append(",signature=")
                .append(Arrays.asList(this.getSignature()).toString())
                .append(",descriptor=")
                .append(this.getDescriptor())
                .append(")")
                .toString();
        }

        // return always the same string representation for this
        // instance (immutable)
        //
        return myToString;
    }

}
Params:	name – cannot be a null or empty string. description – cannot be a null or empty string. signature – can be null or empty if there are no parameters to describe.
Throws:	IllegalArgumentException – if `name` or `description` are null or empty string. ArrayStoreException – If `signature` is not an array of instances of a subclass of `MBeanParameterInfo`.
Params:	obj – the object to be compared for equality with this `OpenMBeanConstructorInfoSupport` instance;
Returns:	`true` if the specified object is equal to this `OpenMBeanConstructorInfoSupport` instance.
/

java/ 15/ java.management/javax/management/openmbean/OpenMBeanConstructorInfoSupport.java
