ojluni/src/main/java/javax/management/openmbean/OpenMBeanParameterInfoSupport.java - platform/libcore - Git at Google

 /*
  * 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.Set;
 import javax.management.Descriptor;
 import javax.management.DescriptorRead;  // for Javadoc
 import javax.management.ImmutableDescriptor;
 import javax.management.MBeanParameterInfo;

 // OpenMBeanAttributeInfoSupport and this class are very similar
 // but can't easily be refactored because there's no multiple inheritance.
 // The best we can do for refactoring is to put a bunch of static methods
 // in OpenMBeanAttributeInfoSupport and import them here.
 import static javax.management.openmbean.OpenMBeanAttributeInfoSupport.*;

 /**
  * Describes a parameter used in one or more operations or
  * constructors of an open MBean.
  *
  *
  * @since 1.5
  */
 public class OpenMBeanParameterInfoSupport
     extends MBeanParameterInfo
     implements OpenMBeanParameterInfo {

     /* Serial version */
     static final long serialVersionUID = -7235016873758443122L;

     /**
      * @serial The open mbean parameter's <i>open type</i>
      */
     private OpenType<?>    openType;

     /**
      * @serial The open mbean parameter's default value
      */
     private Object      defaultValue    = null;

     /**
      * @serial The open mbean parameter's legal values. This {@link
      * Set} is unmodifiable
      */
     private Set<?> legalValues     = null;  // to be constructed unmodifiable

     /**
      * @serial The open mbean parameter's min value
      */
     private Comparable<?> minValue        = null;

     /**
      * @serial The open mbean parameter's max value
      */
     private Comparable<?> maxValue        = null;


     // As this instance is immutable, these two values need only
     // be calculated once.
     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 {@code OpenMBeanParameterInfoSupport} instance,
      * which describes the parameter used in one or more operations or
      * constructors of a class of open MBeans, with the specified
      * {@code name}, {@code openType} and {@code description}.
      *
      * @param name  cannot be a null or empty string.
      *
      * @param description  cannot be a null or empty string.
      *
      * @param openType  cannot be null.
      *
      * @throws IllegalArgumentException if {@code name} or {@code
      * description} are null or empty string, or {@code openType} is
      * null.
      */
     public OpenMBeanParameterInfoSupport(String name,
                                          String description,
                                          OpenType<?> openType) {
         this(name, description, openType, (Descriptor) null);
     }

     /**
      * <p>Constructs an {@code OpenMBeanParameterInfoSupport} instance,
      * which describes the parameter used in one or more operations or
      * constructors of a class of open MBeans, with the specified
      * {@code name}, {@code openType}, {@code description},
      * and {@code descriptor}.</p>
      *
      * <p>The {@code descriptor} can contain entries that will define
      * the values returned by certain methods of this class, as
      * explained in the {@link <a href="package-summary.html#constraints">
      * package description</a>}.
      *
      * @param name  cannot be a null or empty string.
      *
      * @param description  cannot be a null or empty string.
      *
      * @param openType  cannot be null.
      *
      * @param descriptor The descriptor for the parameter.  This may be null
      * which is equivalent to an empty descriptor.
      *
      * @throws IllegalArgumentException if {@code name} or {@code
      * description} are null or empty string, or {@code openType} is
      * null, or the descriptor entries are invalid as described in the
      * {@link <a href="package-summary.html#constraints">package
      * description</a>}.
      *
      * @since 1.6
      */
     public OpenMBeanParameterInfoSupport(String name,
                                          String description,
                                          OpenType<?> openType,
                                          Descriptor descriptor) {


         // Construct parent's state
         //
         super(name,
               (openType==null) ? null : openType.getClassName(),
               description,
               ImmutableDescriptor.union(descriptor,(openType==null)?null:
                 openType.getDescriptor()));

         // Initialize this instance's specific state
         //
         this.openType = openType;

         descriptor = getDescriptor();  // replace null by empty
         this.defaultValue = valueFrom(descriptor, "defaultValue", openType);
         this.legalValues = valuesFrom(descriptor, "legalValues", openType);
         this.minValue = comparableValueFrom(descriptor, "minValue", openType);
         this.maxValue = comparableValueFrom(descriptor, "maxValue", openType);

         try {
             check(this);
         } catch (OpenDataException e) {
             throw new IllegalArgumentException(e.getMessage(), e);
         }
     }


     /**
      * Constructs an {@code OpenMBeanParameterInfoSupport} instance,
      * which describes the parameter used in one or more operations or
      * constructors of a class of open MBeans, with the specified
      * {@code name}, {@code openType}, {@code description} and {@code
      * defaultValue}.
      *
      * @param name  cannot be a null or empty string.
      *
      * @param description  cannot be a null or empty string.
      *
      * @param openType  cannot be null.
      *
      * @param defaultValue must be a valid value for the {@code
      * openType} specified for this parameter; default value not
      * supported for {@code ArrayType} and {@code TabularType}; can be
      * null, in which case it means that no default value is set.
      *
      * @param <T> allows the compiler to check that the {@code defaultValue},
      * if non-null, has the correct Java type for the given {@code openType}.
      *
      * @throws IllegalArgumentException if {@code name} or {@code
      * description} are null or empty string, or {@code openType} is
      * null.
      *
      * @throws OpenDataException if {@code defaultValue} is not a
      * valid value for the specified {@code openType}, or {@code
      * defaultValue} is non null and {@code openType} is an {@code
      * ArrayType} or a {@code TabularType}.
      */
     public <T> OpenMBeanParameterInfoSupport(String   name,
                                              String   description,
                                              OpenType<T> openType,
                                              T        defaultValue)
             throws OpenDataException {
         this(name, description, openType, defaultValue, (T[]) null);
     }

     /**
      * <p>Constructs an {@code OpenMBeanParameterInfoSupport} instance,
      * which describes the parameter used in one or more operations or
      * constructors of a class of open MBeans, with the specified
      * {@code name}, {@code openType}, {@code description}, {@code
      * defaultValue} and {@code legalValues}.</p>
      *
      * <p>The contents of {@code legalValues} are copied, so subsequent
      * modifications of the array referenced by {@code legalValues}
      * have no impact on this {@code OpenMBeanParameterInfoSupport}
      * instance.</p>
      *
      * @param name  cannot be a null or empty string.
      *
      * @param description  cannot be a null or empty string.
      *
      * @param openType  cannot be null.
      *
      * @param defaultValue must be a valid value for the {@code
      * openType} specified for this parameter; default value not
      * supported for {@code ArrayType} and {@code TabularType}; can be
      * null, in which case it means that no default value is set.
      *
      * @param legalValues each contained value must be valid for the
      * {@code openType} specified for this parameter; legal values not
      * supported for {@code ArrayType} and {@code TabularType}; can be
      * null or empty.
      *
      * @param <T> allows the compiler to check that the {@code
      * defaultValue} and {@code legalValues}, if non-null, have the
      * correct Java type for the given {@code openType}.
      *
      * @throws IllegalArgumentException if {@code name} or {@code
      * description} are null or empty string, or {@code openType} is
      * null.
      *
      * @throws OpenDataException if {@code defaultValue} is not a
      * valid value for the specified {@code openType}, or one value in
      * {@code legalValues} is not valid for the specified {@code
      * openType}, or {@code defaultValue} is non null and {@code
      * openType} is an {@code ArrayType} or a {@code TabularType}, or
      * {@code legalValues} is non null and non empty and {@code
      * openType} is an {@code ArrayType} or a {@code TabularType}, or
      * {@code legalValues} is non null and non empty and {@code
      * defaultValue} is not contained in {@code legalValues}.
      */
     public <T> OpenMBeanParameterInfoSupport(String   name,
                                              String   description,
                                              OpenType<T> openType,
                                              T        defaultValue,
                                              T[]      legalValues)
             throws OpenDataException {
         this(name, description, openType,
              defaultValue, legalValues, null, null);
     }


     /**
      * Constructs an {@code OpenMBeanParameterInfoSupport} instance,
      * which describes the parameter used in one or more operations or
      * constructors of a class of open MBeans, with the specified
      * {@code name}, {@code openType}, {@code description}, {@code
      * defaultValue}, {@code minValue} and {@code maxValue}.
      *
      * It is possible to specify minimal and maximal values only for
      * an open type whose values are {@code Comparable}.
      *
      * @param name  cannot be a null or empty string.
      *
      * @param description  cannot be a null or empty string.
      *
      * @param openType  cannot be null.
      *
      * @param defaultValue must be a valid value for the {@code
      * openType} specified for this parameter; default value not
      * supported for {@code ArrayType} and {@code TabularType}; can be
      * null, in which case it means that no default value is set.
      *
      * @param minValue must be valid for the {@code openType}
      * specified for this parameter; can be null, in which case it
      * means that no minimal value is set.
      *
      * @param maxValue must be valid for the {@code openType}
      * specified for this parameter; can be null, in which case it
      * means that no maximal value is set.
      *
      * @param <T> allows the compiler to check that the {@code
      * defaultValue}, {@code minValue}, and {@code maxValue}, if
      * non-null, have the correct Java type for the given {@code
      * openType}.
      *
      * @throws IllegalArgumentException if {@code name} or {@code
      * description} are null or empty string, or {@code openType} is
      * null.
      *
      * @throws OpenDataException if {@code defaultValue}, {@code
      * minValue} or {@code maxValue} is not a valid value for the
      * specified {@code openType}, or {@code defaultValue} is non null
      * and {@code openType} is an {@code ArrayType} or a {@code
      * TabularType}, or both {@code minValue} and {@code maxValue} are
      * non-null and {@code minValue.compareTo(maxValue) > 0} is {@code
      * true}, or both {@code defaultValue} and {@code minValue} are
      * non-null and {@code minValue.compareTo(defaultValue) > 0} is
      * {@code true}, or both {@code defaultValue} and {@code maxValue}
      * are non-null and {@code defaultValue.compareTo(maxValue) > 0}
      * is {@code true}.
      */
     public <T> OpenMBeanParameterInfoSupport(String     name,
                                              String     description,
                                              OpenType<T>   openType,
                                              T          defaultValue,
                                              Comparable<T> minValue,
                                              Comparable<T> maxValue)
             throws OpenDataException {
         this(name, description, openType,
              defaultValue, null, minValue, maxValue);
     }

     private <T> OpenMBeanParameterInfoSupport(String name,
                                               String description,
                                               OpenType<T> openType,
                                               T defaultValue,
                                               T[] legalValues,
                                               Comparable<T> minValue,
                                               Comparable<T> maxValue)
             throws OpenDataException {
         super(name,
               (openType == null) ? null : openType.getClassName(),
               description,
               makeDescriptor(openType,
                              defaultValue, legalValues, minValue, maxValue));

         this.openType = openType;

         Descriptor d = getDescriptor();
         this.defaultValue = defaultValue;
         this.minValue = minValue;
         this.maxValue = maxValue;
         // We already converted the array into an unmodifiable Set
         // in the descriptor.
         this.legalValues = (Set<?>) d.getFieldValue("legalValues");

         check(this);
     }

     /**
      * An object serialized in a version of the API before Descriptors were
      * added to this class will have an empty or null Descriptor.
      * For consistency with our
      * behavior in this version, we must replace the object with one
      * where the Descriptors reflect the same values of openType, defaultValue,
      * etc.
      **/
     private Object readResolve() {
         if (getDescriptor().getFieldNames().length == 0) {
             // This noise allows us to avoid "unchecked" warnings without
             // having to suppress them explicitly.
             OpenType<Object> xopenType = cast(openType);
             Set<Object> xlegalValues = cast(legalValues);
             Comparable<Object> xminValue = cast(minValue);
             Comparable<Object> xmaxValue = cast(maxValue);
             return new OpenMBeanParameterInfoSupport(
                     name, description, openType,
                     makeDescriptor(xopenType, defaultValue, xlegalValues,
                                    xminValue, xmaxValue));
         } else
             return this;
     }

     /**
      * Returns the open type for the values of the parameter described
      * by this {@code OpenMBeanParameterInfoSupport} instance.
      */
     public OpenType<?> getOpenType() {
         return openType;
     }

     /**
      * Returns the default value for the parameter described by this
      * {@code OpenMBeanParameterInfoSupport} instance, if specified,
      * or {@code null} otherwise.
      */
     public Object getDefaultValue() {

         // Special case for ArrayType and TabularType
         // [JF] TODO: clone it so that it cannot be altered,
         // [JF] TODO: if we decide to support defaultValue as an array itself.
         // [JF] As of today (oct 2000) it is not supported so
         // defaultValue is null for arrays. Nothing to do.

         return defaultValue;
     }

     /**
      * Returns an unmodifiable Set of legal values for the parameter
      * described by this {@code OpenMBeanParameterInfoSupport}
      * instance, if specified, or {@code null} otherwise.
      */
     public Set<?> getLegalValues() {

         // Special case for ArrayType and TabularType
         // [JF] TODO: clone values so that they cannot be altered,
         // [JF] TODO: if we decide to support LegalValues as an array itself.
         // [JF] As of today (oct 2000) it is not supported so
         // legalValues is null for arrays. Nothing to do.

         // Returns our legalValues Set (set was constructed unmodifiable)
         return (legalValues);
     }

     /**
      * Returns the minimal value for the parameter described by this
      * {@code OpenMBeanParameterInfoSupport} instance, if specified,
      * or {@code null} otherwise.
      */
     public Comparable<?> getMinValue() {

         // Note: only comparable values have a minValue, so that's not
         // the case of arrays and tabulars (always null).

         return minValue;
     }

     /**
      * Returns the maximal value for the parameter described by this
      * {@code OpenMBeanParameterInfoSupport} instance, if specified,
      * or {@code null} otherwise.
      */
     public Comparable<?> getMaxValue() {

         // Note: only comparable values have a maxValue, so that's not
         // the case of arrays and tabulars (always null).

         return maxValue;
     }

     /**
      * Returns {@code true} if this {@code
      * OpenMBeanParameterInfoSupport} instance specifies a non-null
      * default value for the described parameter, {@code false}
      * otherwise.
      */
     public boolean hasDefaultValue() {

         return (defaultValue != null);
     }

     /**
      * Returns {@code true} if this {@code
      * OpenMBeanParameterInfoSupport} instance specifies a non-null
      * set of legal values for the described parameter, {@code false}
      * otherwise.
      */
     public boolean hasLegalValues() {

         return (legalValues != null);
     }

     /**
      * Returns {@code true} if this {@code
      * OpenMBeanParameterInfoSupport} instance specifies a non-null
      * minimal value for the described parameter, {@code false}
      * otherwise.
      */
     public boolean hasMinValue() {

         return (minValue != null);
     }

     /**
      * Returns {@code true} if this {@code
      * OpenMBeanParameterInfoSupport} instance specifies a non-null
      * maximal value for the described parameter, {@code false}
      * otherwise.
      */
     public boolean hasMaxValue() {

         return (maxValue != null);
     }


     /**
      * Tests whether {@code obj} is a valid value for the parameter
      * described by this {@code OpenMBeanParameterInfo} instance.
      *
      * @param obj the object to be tested.
      *
      * @return {@code true} if {@code obj} is a valid value
      * for the parameter described by this
      * {@code OpenMBeanParameterInfo} instance,
      * {@code false} otherwise.
      */
     public boolean isValue(Object obj) {
         return OpenMBeanAttributeInfoSupport.isValue(this, obj);
         // compiler bug? should be able to omit class name here
         // also below in toString and hashCode
     }


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


     /**
      * <p>Compares the specified {@code obj} parameter with this {@code
      * OpenMBeanParameterInfoSupport} 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 OpenMBeanParameterInfo}
      * interface,</li>
      * <li>their names are equal</li>
      * <li>their open types are equal</li>
      * <li>their default, min, max and legal values are equal.</li>
      * </ul>
      * This ensures that this {@code equals} method works properly for
      * {@code obj} parameters which are different implementations of
      * the {@code OpenMBeanParameterInfo} interface.
      *
      * <p>If {@code obj} also implements {@link DescriptorRead}, then its
      * {@link DescriptorRead#getDescriptor() getDescriptor()} method must
      * also return the same value as for this object.</p>
      *
      * @param obj the object to be compared for equality with this
      * {@code OpenMBeanParameterInfoSupport} instance.
      *
      * @return {@code true} if the specified object is equal to this
      * {@code OpenMBeanParameterInfoSupport} instance.
      */
     public boolean equals(Object obj) {
         if (!(obj instanceof OpenMBeanParameterInfo))
             return false;

         OpenMBeanParameterInfo other = (OpenMBeanParameterInfo) obj;

         return equal(this, other);
     }

     /**
      * <p>Returns the hash code value for this {@code
      * OpenMBeanParameterInfoSupport} instance.</p>
      *
      * <p>The hash code of an {@code OpenMBeanParameterInfoSupport}
      * instance is the sum of the hash codes of all elements of
      * information used in {@code equals} comparisons (ie: its name,
      * its <i>open type</i>, its default, min, max and legal
      * values, and its Descriptor).
      *
      * <p>This ensures that {@code t1.equals(t2)} implies that {@code
      * t1.hashCode()==t2.hashCode()} for any two {@code
      * OpenMBeanParameterInfoSupport} instances {@code t1} and {@code
      * t2}, 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 OpenMBeanParameterInfo} interface may be equal to
      * this {@code OpenMBeanParameterInfoSupport} instance as defined
      * by {@link #equals(java.lang.Object)}, but may have a different
      * hash code if it is calculated differently.
      *
      * <p>As {@code OpenMBeanParameterInfoSupport} 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.
      *
      * @return the hash code value for this {@code
      * OpenMBeanParameterInfoSupport} instance
      */
     public int hashCode() {

         // Calculate the hash code value if it has not yet been done
         // (ie 1st call to hashCode())
         //
         if (myHashCode == null)
             myHashCode = OpenMBeanAttributeInfoSupport.hashCode(this);

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

     /**
      * Returns a string representation of this
      * {@code OpenMBeanParameterInfoSupport} instance.
      * <p>
      * The string representation consists of the name of this class (i.e.
      * {@code javax.management.openmbean.OpenMBeanParameterInfoSupport}),
      * the string representation of the name and open type of the described
      * parameter, the string representation of its default, min, max and legal
      * values and the string representation of its descriptor.
      * <p>
      * As {@code OpenMBeanParameterInfoSupport} 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.
      *
      * @return a string representation of this
      * {@code OpenMBeanParameterInfoSupport} instance.
      */
     public String toString() {

         // Calculate the string value if it has not yet been done (ie
         // 1st call to toString())
         //
         if (myToString == null)
             myToString = OpenMBeanAttributeInfoSupport.toString(this);

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

 }
	/*
	* 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.Set;
	import javax.management.Descriptor;
	import javax.management.DescriptorRead; // for Javadoc
	import javax.management.ImmutableDescriptor;
	import javax.management.MBeanParameterInfo;

	// OpenMBeanAttributeInfoSupport and this class are very similar
	// but can't easily be refactored because there's no multiple inheritance.
	// The best we can do for refactoring is to put a bunch of static methods
	// in OpenMBeanAttributeInfoSupport and import them here.
	import static javax.management.openmbean.OpenMBeanAttributeInfoSupport.*;

	/**
	* Describes a parameter used in one or more operations or
	* constructors of an open MBean.
	*
	*
	* @since 1.5
	*/
	public class OpenMBeanParameterInfoSupport
	extends MBeanParameterInfo
	implements OpenMBeanParameterInfo {

	/* Serial version */
	static final long serialVersionUID = -7235016873758443122L;

	/**
	* @serial The open mbean parameter's <i>open type</i>
	*/
	private OpenType<?> openType;

	/**
	* @serial The open mbean parameter's default value
	*/
	private Object defaultValue = null;

	/**
	* @serial The open mbean parameter's legal values. This {@link
	* Set} is unmodifiable
	*/
	private Set<?> legalValues = null; // to be constructed unmodifiable

	/**
	* @serial The open mbean parameter's min value
	*/
	private Comparable<?> minValue = null;

	/**
	* @serial The open mbean parameter's max value
	*/
	private Comparable<?> maxValue = null;


	// As this instance is immutable, these two values need only
	// be calculated once.
	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 {@code OpenMBeanParameterInfoSupport} instance,
	* which describes the parameter used in one or more operations or
	* constructors of a class of open MBeans, with the specified
	* {@code name}, {@code openType} and {@code description}.
	*
	* @param name cannot be a null or empty string.
	*
	* @param description cannot be a null or empty string.
	*
	* @param openType cannot be null.
	*
	* @throws IllegalArgumentException if {@code name} or {@code
	* description} are null or empty string, or {@code openType} is
	* null.
	*/
	public OpenMBeanParameterInfoSupport(String name,
	String description,
	OpenType<?> openType) {
	this(name, description, openType, (Descriptor) null);
	}

	/**
	* <p>Constructs an {@code OpenMBeanParameterInfoSupport} instance,
	* which describes the parameter used in one or more operations or
	* constructors of a class of open MBeans, with the specified
	* {@code name}, {@code openType}, {@code description},
	* and {@code descriptor}.</p>
	*
	* <p>The {@code descriptor} can contain entries that will define
	* the values returned by certain methods of this class, as
	* explained in the {@link <a href="package-summary.html#constraints">
	* package description</a>}.
	*
	* @param name cannot be a null or empty string.
	*
	* @param description cannot be a null or empty string.
	*
	* @param openType cannot be null.
	*
	* @param descriptor The descriptor for the parameter. This may be null
	* which is equivalent to an empty descriptor.
	*
	* @throws IllegalArgumentException if {@code name} or {@code
	* description} are null or empty string, or {@code openType} is
	* null, or the descriptor entries are invalid as described in the
	* {@link <a href="package-summary.html#constraints">package
	* description</a>}.
	*
	* @since 1.6
	*/
	public OpenMBeanParameterInfoSupport(String name,
	String description,
	OpenType<?> openType,
	Descriptor descriptor) {


	// Construct parent's state
	//
	super(name,
	(openType==null) ? null : openType.getClassName(),
	description,
	ImmutableDescriptor.union(descriptor,(openType==null)?null:
	openType.getDescriptor()));

	// Initialize this instance's specific state
	//
	this.openType = openType;

	descriptor = getDescriptor(); // replace null by empty
	this.defaultValue = valueFrom(descriptor, "defaultValue", openType);
	this.legalValues = valuesFrom(descriptor, "legalValues", openType);
	this.minValue = comparableValueFrom(descriptor, "minValue", openType);
	this.maxValue = comparableValueFrom(descriptor, "maxValue", openType);

	try {
	check(this);
	} catch (OpenDataException e) {
	throw new IllegalArgumentException(e.getMessage(), e);
	}
	}


	/**
	* Constructs an {@code OpenMBeanParameterInfoSupport} instance,
	* which describes the parameter used in one or more operations or
	* constructors of a class of open MBeans, with the specified
	* {@code name}, {@code openType}, {@code description} and {@code
	* defaultValue}.
	*
	* @param name cannot be a null or empty string.
	*
	* @param description cannot be a null or empty string.
	*
	* @param openType cannot be null.
	*
	* @param defaultValue must be a valid value for the {@code
	* openType} specified for this parameter; default value not
	* supported for {@code ArrayType} and {@code TabularType}; can be
	* null, in which case it means that no default value is set.
	*
	* @param <T> allows the compiler to check that the {@code defaultValue},
	* if non-null, has the correct Java type for the given {@code openType}.
	*
	* @throws IllegalArgumentException if {@code name} or {@code
	* description} are null or empty string, or {@code openType} is
	* null.
	*
	* @throws OpenDataException if {@code defaultValue} is not a
	* valid value for the specified {@code openType}, or {@code
	* defaultValue} is non null and {@code openType} is an {@code
	* ArrayType} or a {@code TabularType}.
	*/
	public <T> OpenMBeanParameterInfoSupport(String name,
	String description,
	OpenType<T> openType,
	T defaultValue)
	throws OpenDataException {
	this(name, description, openType, defaultValue, (T[]) null);
	}

	/**
	* <p>Constructs an {@code OpenMBeanParameterInfoSupport} instance,
	* which describes the parameter used in one or more operations or
	* constructors of a class of open MBeans, with the specified
	* {@code name}, {@code openType}, {@code description}, {@code
	* defaultValue} and {@code legalValues}.</p>
	*
	* <p>The contents of {@code legalValues} are copied, so subsequent
	* modifications of the array referenced by {@code legalValues}
	* have no impact on this {@code OpenMBeanParameterInfoSupport}
	* instance.</p>
	*
	* @param name cannot be a null or empty string.
	*
	* @param description cannot be a null or empty string.
	*
	* @param openType cannot be null.
	*
	* @param defaultValue must be a valid value for the {@code
	* openType} specified for this parameter; default value not
	* supported for {@code ArrayType} and {@code TabularType}; can be
	* null, in which case it means that no default value is set.
	*
	* @param legalValues each contained value must be valid for the
	* {@code openType} specified for this parameter; legal values not
	* supported for {@code ArrayType} and {@code TabularType}; can be
	* null or empty.
	*
	* @param <T> allows the compiler to check that the {@code
	* defaultValue} and {@code legalValues}, if non-null, have the
	* correct Java type for the given {@code openType}.
	*
	* @throws IllegalArgumentException if {@code name} or {@code
	* description} are null or empty string, or {@code openType} is
	* null.
	*
	* @throws OpenDataException if {@code defaultValue} is not a
	* valid value for the specified {@code openType}, or one value in
	* {@code legalValues} is not valid for the specified {@code
	* openType}, or {@code defaultValue} is non null and {@code
	* openType} is an {@code ArrayType} or a {@code TabularType}, or
	* {@code legalValues} is non null and non empty and {@code
	* openType} is an {@code ArrayType} or a {@code TabularType}, or
	* {@code legalValues} is non null and non empty and {@code
	* defaultValue} is not contained in {@code legalValues}.
	*/
	public <T> OpenMBeanParameterInfoSupport(String name,
	String description,
	OpenType<T> openType,
	T defaultValue,
	T[] legalValues)
	throws OpenDataException {
	this(name, description, openType,
	defaultValue, legalValues, null, null);
	}


	/**
	* Constructs an {@code OpenMBeanParameterInfoSupport} instance,
	* which describes the parameter used in one or more operations or
	* constructors of a class of open MBeans, with the specified
	* {@code name}, {@code openType}, {@code description}, {@code
	* defaultValue}, {@code minValue} and {@code maxValue}.
	*
	* It is possible to specify minimal and maximal values only for
	* an open type whose values are {@code Comparable}.
	*
	* @param name cannot be a null or empty string.
	*
	* @param description cannot be a null or empty string.
	*
	* @param openType cannot be null.
	*
	* @param defaultValue must be a valid value for the {@code
	* openType} specified for this parameter; default value not
	* supported for {@code ArrayType} and {@code TabularType}; can be
	* null, in which case it means that no default value is set.
	*
	* @param minValue must be valid for the {@code openType}
	* specified for this parameter; can be null, in which case it
	* means that no minimal value is set.
	*
	* @param maxValue must be valid for the {@code openType}
	* specified for this parameter; can be null, in which case it
	* means that no maximal value is set.
	*
	* @param <T> allows the compiler to check that the {@code
	* defaultValue}, {@code minValue}, and {@code maxValue}, if
	* non-null, have the correct Java type for the given {@code
	* openType}.
	*
	* @throws IllegalArgumentException if {@code name} or {@code
	* description} are null or empty string, or {@code openType} is
	* null.
	*
	* @throws OpenDataException if {@code defaultValue}, {@code
	* minValue} or {@code maxValue} is not a valid value for the
	* specified {@code openType}, or {@code defaultValue} is non null
	* and {@code openType} is an {@code ArrayType} or a {@code
	* TabularType}, or both {@code minValue} and {@code maxValue} are
	* non-null and {@code minValue.compareTo(maxValue) > 0} is {@code
	* true}, or both {@code defaultValue} and {@code minValue} are
	* non-null and {@code minValue.compareTo(defaultValue) > 0} is
	* {@code true}, or both {@code defaultValue} and {@code maxValue}
	* are non-null and {@code defaultValue.compareTo(maxValue) > 0}
	* is {@code true}.
	*/
	public <T> OpenMBeanParameterInfoSupport(String name,
	String description,
	OpenType<T> openType,
	T defaultValue,
	Comparable<T> minValue,
	Comparable<T> maxValue)
	throws OpenDataException {
	this(name, description, openType,
	defaultValue, null, minValue, maxValue);
	}

	private <T> OpenMBeanParameterInfoSupport(String name,
	String description,
	OpenType<T> openType,
	T defaultValue,
	T[] legalValues,
	Comparable<T> minValue,
	Comparable<T> maxValue)
	throws OpenDataException {
	super(name,
	(openType == null) ? null : openType.getClassName(),
	description,
	makeDescriptor(openType,
	defaultValue, legalValues, minValue, maxValue));

	this.openType = openType;

	Descriptor d = getDescriptor();
	this.defaultValue = defaultValue;
	this.minValue = minValue;
	this.maxValue = maxValue;
	// We already converted the array into an unmodifiable Set
	// in the descriptor.
	this.legalValues = (Set<?>) d.getFieldValue("legalValues");

	check(this);
	}

	/**
	* An object serialized in a version of the API before Descriptors were
	* added to this class will have an empty or null Descriptor.
	* For consistency with our
	* behavior in this version, we must replace the object with one
	* where the Descriptors reflect the same values of openType, defaultValue,
	* etc.
	**/
	private Object readResolve() {
	if (getDescriptor().getFieldNames().length == 0) {
	// This noise allows us to avoid "unchecked" warnings without
	// having to suppress them explicitly.
	OpenType<Object> xopenType = cast(openType);
	Set<Object> xlegalValues = cast(legalValues);
	Comparable<Object> xminValue = cast(minValue);
	Comparable<Object> xmaxValue = cast(maxValue);
	return new OpenMBeanParameterInfoSupport(
	name, description, openType,
	makeDescriptor(xopenType, defaultValue, xlegalValues,
	xminValue, xmaxValue));
	} else
	return this;
	}

	/**
	* Returns the open type for the values of the parameter described
	* by this {@code OpenMBeanParameterInfoSupport} instance.
	*/
	public OpenType<?> getOpenType() {
	return openType;
	}

	/**
	* Returns the default value for the parameter described by this
	* {@code OpenMBeanParameterInfoSupport} instance, if specified,
	* or {@code null} otherwise.
	*/
	public Object getDefaultValue() {

	// Special case for ArrayType and TabularType
	// [JF] TODO: clone it so that it cannot be altered,
	// [JF] TODO: if we decide to support defaultValue as an array itself.
	// [JF] As of today (oct 2000) it is not supported so
	// defaultValue is null for arrays. Nothing to do.

	return defaultValue;
	}

	/**
	* Returns an unmodifiable Set of legal values for the parameter
	* described by this {@code OpenMBeanParameterInfoSupport}
	* instance, if specified, or {@code null} otherwise.
	*/
	public Set<?> getLegalValues() {

	// Special case for ArrayType and TabularType
	// [JF] TODO: clone values so that they cannot be altered,
	// [JF] TODO: if we decide to support LegalValues as an array itself.
	// [JF] As of today (oct 2000) it is not supported so
	// legalValues is null for arrays. Nothing to do.

	// Returns our legalValues Set (set was constructed unmodifiable)
	return (legalValues);
	}

	/**
	* Returns the minimal value for the parameter described by this
	* {@code OpenMBeanParameterInfoSupport} instance, if specified,
	* or {@code null} otherwise.
	*/
	public Comparable<?> getMinValue() {

	// Note: only comparable values have a minValue, so that's not
	// the case of arrays and tabulars (always null).

	return minValue;
	}

	/**
	* Returns the maximal value for the parameter described by this
	* {@code OpenMBeanParameterInfoSupport} instance, if specified,
	* or {@code null} otherwise.
	*/
	public Comparable<?> getMaxValue() {

	// Note: only comparable values have a maxValue, so that's not
	// the case of arrays and tabulars (always null).

	return maxValue;
	}

	/**
	* Returns {@code true} if this {@code
	* OpenMBeanParameterInfoSupport} instance specifies a non-null
	* default value for the described parameter, {@code false}
	* otherwise.
	*/
	public boolean hasDefaultValue() {

	return (defaultValue != null);
	}

	/**
	* Returns {@code true} if this {@code
	* OpenMBeanParameterInfoSupport} instance specifies a non-null
	* set of legal values for the described parameter, {@code false}
	* otherwise.
	*/
	public boolean hasLegalValues() {

	return (legalValues != null);
	}

	/**
	* Returns {@code true} if this {@code
	* OpenMBeanParameterInfoSupport} instance specifies a non-null
	* minimal value for the described parameter, {@code false}
	* otherwise.
	*/
	public boolean hasMinValue() {

	return (minValue != null);
	}

	/**
	* Returns {@code true} if this {@code
	* OpenMBeanParameterInfoSupport} instance specifies a non-null
	* maximal value for the described parameter, {@code false}
	* otherwise.
	*/
	public boolean hasMaxValue() {

	return (maxValue != null);
	}


	/**
	* Tests whether {@code obj} is a valid value for the parameter
	* described by this {@code OpenMBeanParameterInfo} instance.
	*
	* @param obj the object to be tested.
	*
	* @return {@code true} if {@code obj} is a valid value
	* for the parameter described by this
	* {@code OpenMBeanParameterInfo} instance,
	* {@code false} otherwise.
	*/
	public boolean isValue(Object obj) {
	return OpenMBeanAttributeInfoSupport.isValue(this, obj);
	// compiler bug? should be able to omit class name here
	// also below in toString and hashCode
	}


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


	/**
	* <p>Compares the specified {@code obj} parameter with this {@code
	* OpenMBeanParameterInfoSupport} 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 OpenMBeanParameterInfo}
	* interface,</li>
	* <li>their names are equal</li>
	* <li>their open types are equal</li>
	* <li>their default, min, max and legal values are equal.</li>
	* </ul>
	* This ensures that this {@code equals} method works properly for
	* {@code obj} parameters which are different implementations of
	* the {@code OpenMBeanParameterInfo} interface.
	*
	* <p>If {@code obj} also implements {@link DescriptorRead}, then its
	* {@link DescriptorRead#getDescriptor() getDescriptor()} method must
	* also return the same value as for this object.</p>
	*
	* @param obj the object to be compared for equality with this
	* {@code OpenMBeanParameterInfoSupport} instance.
	*
	* @return {@code true} if the specified object is equal to this
	* {@code OpenMBeanParameterInfoSupport} instance.
	*/
	public boolean equals(Object obj) {
	if (!(obj instanceof OpenMBeanParameterInfo))
	return false;

	OpenMBeanParameterInfo other = (OpenMBeanParameterInfo) obj;

	return equal(this, other);
	}

	/**
	* <p>Returns the hash code value for this {@code
	* OpenMBeanParameterInfoSupport} instance.</p>
	*
	* <p>The hash code of an {@code OpenMBeanParameterInfoSupport}
	* instance is the sum of the hash codes of all elements of
	* information used in {@code equals} comparisons (ie: its name,
	* its <i>open type</i>, its default, min, max and legal
	* values, and its Descriptor).
	*
	* <p>This ensures that {@code t1.equals(t2)} implies that {@code
	* t1.hashCode()==t2.hashCode()} for any two {@code
	* OpenMBeanParameterInfoSupport} instances {@code t1} and {@code
	* t2}, 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 OpenMBeanParameterInfo} interface may be equal to
	* this {@code OpenMBeanParameterInfoSupport} instance as defined
	* by {@link #equals(java.lang.Object)}, but may have a different
	* hash code if it is calculated differently.
	*
	* <p>As {@code OpenMBeanParameterInfoSupport} 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.
	*
	* @return the hash code value for this {@code
	* OpenMBeanParameterInfoSupport} instance
	*/
	public int hashCode() {

	// Calculate the hash code value if it has not yet been done
	// (ie 1st call to hashCode())
	//
	if (myHashCode == null)
	myHashCode = OpenMBeanAttributeInfoSupport.hashCode(this);

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

	/**
	* Returns a string representation of this
	* {@code OpenMBeanParameterInfoSupport} instance.
	* <p>
	* The string representation consists of the name of this class (i.e.
	* {@code javax.management.openmbean.OpenMBeanParameterInfoSupport}),
	* the string representation of the name and open type of the described
	* parameter, the string representation of its default, min, max and legal
	* values and the string representation of its descriptor.
	* <p>
	* As {@code OpenMBeanParameterInfoSupport} 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.
	*
	* @return a string representation of this
	* {@code OpenMBeanParameterInfoSupport} instance.
	*/
	public String toString() {

	// Calculate the string value if it has not yet been done (ie
	// 1st call to toString())
	//
	if (myToString == null)
	myToString = OpenMBeanAttributeInfoSupport.toString(this);

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

	}