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 * Copyright (c) 1999, 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
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package javax.management;

import com.sun.jmx.mbeanserver.Introspector;
import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.util.Arrays;
import java.util.Objects;


Describes a constructor exposed by an MBean.  Instances of this
class are immutable.  Subclasses may be mutable but this is not
recommended.

Since:1.5
/**
 * Describes a constructor exposed by an MBean.  Instances of this
 * class are immutable.  Subclasses may be mutable but this is not
 * recommended.
 *
 * @since 1.5
 */
public class MBeanConstructorInfo extends MBeanFeatureInfo implements Cloneable {

    /* Serial version */
    static final long serialVersionUID = 4433990064191844427L;

    static final MBeanConstructorInfo[] NO_CONSTRUCTORS =
        new MBeanConstructorInfo[0];

    
See Also:
/** @see MBeanInfo#arrayGettersSafe */
    private final transient boolean arrayGettersSafe;

    
@serialThe signature of the method, that is, the class names of the arguments.
/**
     * @serial The signature of the method, that is, the class names of the arguments.
     */
    private final MBeanParameterInfo[] signature;

    
Constructs an MBeanConstructorInfo object. The Descriptor of the constructed object will include fields contributed by any annotations on the 
Constructor object that contain the DescriptorKey meta-annotation. 
Params:
  • description – A human readable description of the operation.
  • constructor – The java.lang.reflect.Constructor
object describing the MBean constructor.
/**
     * Constructs an <CODE>MBeanConstructorInfo</CODE> object.  The
     * {@link Descriptor} of the constructed object will include
     * fields contributed by any annotations on the {@code
     * Constructor} object that contain the {@link DescriptorKey}
     * meta-annotation.
     *
     * @param description A human readable description of the operation.
     * @param constructor The <CODE>java.lang.reflect.Constructor</CODE>
     * object describing the MBean constructor.
     */
    public MBeanConstructorInfo(String description, Constructor<?> constructor) {
        this(constructor.getName(), description,
             constructorSignature(constructor),
             Introspector.descriptorForElement(constructor));
    }

    
Constructs an MBeanConstructorInfo object.

Params:
  • name – The name of the constructor.
  • signature – MBeanParameterInfo objects
describing the parameters(arguments) of the constructor.  This
may be null with the same effect as a zero-length array.
  • description – A human readable description of the constructor.
/**
     * Constructs an <CODE>MBeanConstructorInfo</CODE> object.
     *
     * @param name The name of the constructor.
     * @param signature <CODE>MBeanParameterInfo</CODE> objects
     * describing the parameters(arguments) of the constructor.  This
     * may be null with the same effect as a zero-length array.
     * @param description A human readable description of the constructor.
     */
    public MBeanConstructorInfo(String name,
                                String description,
                                MBeanParameterInfo[] signature) {
        this(name, description, signature, null);
    }

    
Constructs an MBeanConstructorInfo object.

Params:
  • name – The name of the constructor.
  • signature – MBeanParameterInfo objects
describing the parameters(arguments) of the constructor.  This
may be null with the same effect as a zero-length array.
  • description – A human readable description of the constructor.
  • descriptor – The descriptor for the constructor.  This may be null
which is equivalent to an empty descriptor.
Since:1.6
/**
     * Constructs an <CODE>MBeanConstructorInfo</CODE> object.
     *
     * @param name The name of the constructor.
     * @param signature <CODE>MBeanParameterInfo</CODE> objects
     * describing the parameters(arguments) of the constructor.  This
     * may be null with the same effect as a zero-length array.
     * @param description A human readable description of the constructor.
     * @param descriptor The descriptor for the constructor.  This may be null
     * which is equivalent to an empty descriptor.
     *
     * @since 1.6
     */
    public MBeanConstructorInfo(String name,
                                String description,
                                MBeanParameterInfo[] signature,
                                Descriptor descriptor) {
        super(name, description, descriptor);

        if (signature == null || signature.length == 0)
            signature = MBeanParameterInfo.NO_PARAMS;
        else
            signature = signature.clone();
        this.signature = signature;
        this.arrayGettersSafe =
            MBeanInfo.arrayGettersSafe(this.getClass(),
                                       MBeanConstructorInfo.class);
    }


    
Returns a shallow clone of this instance.  The clone is
obtained by simply calling super.clone(), thus calling
the default native shallow cloning mechanism implemented by
Object.clone().  No deeper cloning of any internal
field is made.


Since this class is immutable, cloning is chiefly of
interest to subclasses.


/**
     * <p>Returns a shallow clone of this instance.  The clone is
     * obtained by simply calling <tt>super.clone()</tt>, thus calling
     * the default native shallow cloning mechanism implemented by
     * <tt>Object.clone()</tt>.  No deeper cloning of any internal
     * field is made.</p>
     *
     * <p>Since this class is immutable, cloning is chiefly of
     * interest to subclasses.</p>
     */
     public Object clone () {
         try {
             return super.clone() ;
         } catch (CloneNotSupportedException e) {
             // should not happen as this class is cloneable
             return null;
         }
     }

    
Returns the list of parameters for this constructor.  Each
parameter is described by an MBeanParameterInfo
object.


The returned array is a shallow copy of the internal array,
which means that it is a copy of the internal array of
references to the MBeanParameterInfo objects but
that each referenced MBeanParameterInfo object is
not copied.


Returns: An array of MBeanParameterInfo objects.
/**
     * <p>Returns the list of parameters for this constructor.  Each
     * parameter is described by an <CODE>MBeanParameterInfo</CODE>
     * object.</p>
     *
     * <p>The returned array is a shallow copy of the internal array,
     * which means that it is a copy of the internal array of
     * references to the <CODE>MBeanParameterInfo</CODE> objects but
     * that each referenced <CODE>MBeanParameterInfo</CODE> object is
     * not copied.</p>
     *
     * @return  An array of <CODE>MBeanParameterInfo</CODE> objects.
     */
    public MBeanParameterInfo[] getSignature() {
        if (signature.length == 0)
            return signature;
        else
            return signature.clone();
    }

    private MBeanParameterInfo[] fastGetSignature() {
        if (arrayGettersSafe)
            return signature;
        else
            return getSignature();
    }

    public String toString() {
        return
            getClass().getName() + "[" +
            "description=" + getDescription() + ", " +
            "name=" + getName() + ", " +
            "signature=" + Arrays.asList(fastGetSignature()) + ", " +
            "descriptor=" + getDescriptor() +
            "]";
    }

    
Compare this MBeanConstructorInfo to another.

Params:
  • o – the object to compare to.
Returns:true if and only if o is an MBeanConstructorInfo such that its MBeanFeatureInfo.getName(), MBeanFeatureInfo.getDescription(), getSignature(), and MBeanFeatureInfo.getDescriptor() values are equal (not necessarily identical) to those of this MBeanConstructorInfo. Two signature arrays are equal if their elements are pairwise equal.
/**
     * Compare this MBeanConstructorInfo to another.
     *
     * @param o the object to compare to.
     *
     * @return true if and only if <code>o</code> is an MBeanConstructorInfo such
     * that its {@link #getName()}, {@link #getDescription()},
     * {@link #getSignature()}, and {@link #getDescriptor()}
     * values are equal (not necessarily
     * identical) to those of this MBeanConstructorInfo.  Two
     * signature arrays are equal if their elements are pairwise
     * equal.
     */
    public boolean equals(Object o) {
        if (o == this)
            return true;
        if (!(o instanceof MBeanConstructorInfo))
            return false;
        MBeanConstructorInfo p = (MBeanConstructorInfo) o;
        return (Objects.equals(p.getName(), getName()) &&
                Objects.equals(p.getDescription(), getDescription()) &&
                Arrays.equals(p.fastGetSignature(), fastGetSignature()) &&
                Objects.equals(p.getDescriptor(), getDescriptor()));
    }

    /* Unlike attributes and operations, it's quite likely we'll have
       more than one constructor with the same name and even
       description, so we include the parameter array in the hashcode.
       We don't include the description, though, because it could be
       quite long and yet the same between constructors.  Likewise for
       the descriptor.  */
    public int hashCode() {
        return Objects.hash(getName()) ^ Arrays.hashCode(fastGetSignature());
    }

    private static MBeanParameterInfo[] constructorSignature(Constructor<?> cn) {
        final Class<?>[] classes = cn.getParameterTypes();
        final Annotation[][] annots = cn.getParameterAnnotations();
        return MBeanOperationInfo.parameters(classes, annots);
    }
}