Back to index...

	/*
	* 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.ImmutableDescriptor;
	import javax.management.MBeanOperationInfo;
	import javax.management.MBeanParameterInfo;


	/**
	* Describes an operation of an Open MBean.
	*
	*
	* @since 1.5
	*/
	public class OpenMBeanOperationInfoSupport
	extends MBeanOperationInfo
	implements OpenMBeanOperationInfo {

	/* Serial version */
	static final long serialVersionUID = 4996859732565369366L;

	/**
	* @serial The <i>open type</i> of the values returned by the operation
	* described by this {@link OpenMBeanOperationInfo} instance
	*
	*/
	private OpenType<?> returnOpenType;


	// 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 OpenMBeanOperationInfoSupport}
	* instance, which describes the operation of a class of open
	* MBeans, with the specified {@code name}, {@code description},
	* {@code signature}, {@code returnOpenType} and {@code
	* impact}.</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 returnOpenType cannot be null: use {@code
	* SimpleType.VOID} for operations that return nothing.
	*
	* @param impact must be one of {@code ACTION}, {@code
	* ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}.
	*
	* @throws IllegalArgumentException if {@code name} or {@code
	* description} are null or empty string, or {@code
	* returnOpenType} is null, or {@code impact} is not one of {@code
	* ACTION}, {@code ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}.
	*
	* @throws ArrayStoreException If {@code signature} is not an
	* array of instances of a subclass of {@code MBeanParameterInfo}.
	*/
	public OpenMBeanOperationInfoSupport(String name,
	String description,
	OpenMBeanParameterInfo[] signature,
	OpenType<?> returnOpenType,
	int impact) {
	this(name, description, signature, returnOpenType, impact,
	(Descriptor) null);
	}

	/**
	* <p>Constructs an {@code OpenMBeanOperationInfoSupport}
	* instance, which describes the operation of a class of open
	* MBeans, with the specified {@code name}, {@code description},
	* {@code signature}, {@code returnOpenType}, {@code
	* impact}, 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 returnOpenType cannot be null: use {@code
	* SimpleType.VOID} for operations that return nothing.
	*
	* @param impact must be one of {@code ACTION}, {@code
	* ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}.
	*
	* @param descriptor The descriptor for the operation. 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
	* returnOpenType} is null, or {@code impact} is not one of {@code
	* ACTION}, {@code ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}.
	*
	* @throws ArrayStoreException If {@code signature} is not an
	* array of instances of a subclass of {@code MBeanParameterInfo}.
	*
	* @since 1.6
	*/
	public OpenMBeanOperationInfoSupport(String name,
	String description,
	OpenMBeanParameterInfo[] signature,
	OpenType<?> returnOpenType,
	int impact,
	Descriptor descriptor) {
	super(name,
	description,
	arrayCopyCast(signature),
	// must prevent NPE here - we will throw IAE later on if
	// returnOpenType is null
	(returnOpenType == null) ? null : returnOpenType.getClassName(),
	impact,
	ImmutableDescriptor.union(descriptor,
	// must prevent NPE here - we will throw IAE later on if
	// returnOpenType is null
	(returnOpenType==null) ? null :returnOpenType.getDescriptor()));

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

	if (impact != ACTION && impact != ACTION_INFO && impact != INFO &&
	impact != UNKNOWN) {
	throw new IllegalArgumentException("Argument impact can only be " +
	"one of ACTION, ACTION_INFO, " +
	"INFO, or UNKNOWN: " + impact);
	}

	this.returnOpenType = returnOpenType;
	}


	// Converts an array of OpenMBeanParameterInfo objects extending
	// MBeanParameterInfo into an array of MBeanParameterInfo.
	//
	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;
	}

	// Converts an array of MBeanParameterInfo objects implementing
	// OpenMBeanParameterInfo into an array of OpenMBeanParameterInfo.
	//
	private static OpenMBeanParameterInfo[]
	arrayCopyCast(MBeanParameterInfo[] src) {
	if (src == null)
	return null;

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


	// [JF]: should we add constructor with java.lang.reflect.Method
	// method parameter ? would need to add consistency check between
	// OpenType<?> returnOpenType and method.getReturnType().


	/**
	* Returns the <i>open type</i> of the values returned by the
	* operation described by this {@code OpenMBeanOperationInfo}
	* instance.
	*/
	public OpenType<?> getReturnOpenType() {

	return returnOpenType;
	}



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


	/**
	* <p>Compares the specified {@code obj} parameter with this
	* {@code OpenMBeanOperationInfoSupport} 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
	* OpenMBeanOperationInfo} interface,</li>
	* <li>their names are equal</li>
	* <li>their signatures are equal</li>
	* <li>their return open types are equal</li>
	* <li>their impacts are equal</li>
	* </ul>
	*
	* This ensures that this {@code equals} method works properly for
	* {@code obj} parameters which are different implementations of
	* the {@code OpenMBeanOperationInfo} interface.
	*
	* @param obj the object to be compared for equality with this
	* {@code OpenMBeanOperationInfoSupport} instance;
	*
	* @return {@code true} if the specified object is equal to this
	* {@code OpenMBeanOperationInfoSupport} instance.
	*/
	public boolean equals(Object obj) {

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

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

	// Now, really test for equality between this
	// OpenMBeanOperationInfo 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;
	}

	// their return open types should be equal
	if ( ! this.getReturnOpenType().equals(other.getReturnOpenType()) ) {
	return false;
	}

	// their impacts should be equal
	if ( this.getImpact() != other.getImpact() ) {
	return false;
	}

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

	/**
	* <p>Returns the hash code value for this {@code
	* OpenMBeanOperationInfoSupport} instance.</p>
	*
	* <p>The hash code of an {@code OpenMBeanOperationInfoSupport}
	* instance is the sum of the hash codes of all elements of
	* information used in {@code equals} comparisons (ie: its name,
	* return open type, impact 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
	* OpenMBeanOperationInfoSupport} 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 OpenMBeanOperationInfo} interface may be equal to
	* this {@code OpenMBeanOperationInfoSupport} 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 OpenMBeanOperationInfoSupport} 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
	* OpenMBeanOperationInfoSupport} 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();
	value += this.getReturnOpenType().hashCode();
	value += this.getImpact();
	myHashCode = Integer.valueOf(value);
	}

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

	/**
	* <p>Returns a string representation of this {@code
	* OpenMBeanOperationInfoSupport} instance.</p>
	*
	* <p>The string representation consists of the name of this class
	* (ie {@code
	* javax.management.openmbean.OpenMBeanOperationInfoSupport}), and
	* the name, signature, return open type and impact of the
	* described operation and the string representation of its descriptor.</p>
	*
	* <p>As {@code OpenMBeanOperationInfoSupport} 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
	* OpenMBeanOperationInfoSupport} 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 StringBuilder()
	.append(this.getClass().getName())
	.append("(name=")
	.append(this.getName())
	.append(",signature=")
	.append(Arrays.asList(this.getSignature()).toString())
	.append(",return=")
	.append(this.getReturnOpenType().toString())
	.append(",impact=")
	.append(this.getImpact())
	.append(",descriptor=")
	.append(this.getDescriptor())
	.append(")")
	.toString();
	}

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

	/**
	* 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 value of returned openType.
	**/
	private Object readResolve() {
	if (getDescriptor().getFieldNames().length == 0) {
	// This constructor will construct the expected default Descriptor.
	//
	return new OpenMBeanOperationInfoSupport(
	name, description, arrayCopyCast(getSignature()),
	returnOpenType, getImpact());
	} else
	return this;
	}

	}

Back to index...