/* * @(#)OpenMBeanOperationInfoSupport.java 3.25 03/12/19 * * Copyright 2004 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.management.openmbean; // java import // import java.io.Serializable; import java.util.Arrays; // jmx import // import javax.management.MBeanOperationInfo; import javax.management.MBeanParameterInfo; /** * Describes an operation of an Open MBean. * * @version 3.25 03/12/19 * @author Sun Microsystems, Inc. * * @since 1.5 * @since.unbundled JMX 1.1 */ public class OpenMBeanOperationInfoSupport extends MBeanOperationInfo implements OpenMBeanOperationInfo, Serializable { /* Serial version */ static final long serialVersionUID = 4996859732565369366L; /** * @serial The open type of the values returned by the operation * described by this {@link OpenMBeanOperationInfo} instance * */ private OpenType returnOpenType; 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 OpenMBeanOperationInfoSupport instance, which describes the operation * of a class of open MBeans, with the specified * name, description, signature, returnOpenType and impact. *

* The signature array parameter is internally copied, so that subsequent changes * to the array referenced by signature have no effect on this instance. *

* * @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 SimpleType.VOID for operations that return nothing. * * @param impact can be only one of ACTION, ACTION_INFO or INFO. * * @throws IllegalArgumentException if name or description are null or empty string, * or returnOpenType is null, * or impact is not one of ACTION, ACTION_INFO or INFO. * * @throws ArrayStoreException If signature is not an array of instances of a subclass of MBeanParameterInfo. */ public OpenMBeanOperationInfoSupport(String name, String description, OpenMBeanParameterInfo[] signature, OpenType returnOpenType, int impact) { super(name, description, ( signature == null ? null : arrayCopyCast(signature) ), // may throw an ArrayStoreException ( returnOpenType == null ? null : returnOpenType.getClassName() ), impact); // 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."); } // check impact's value is only one of the 3 allowed (UNKNOWN not allowed) // if ( (impact != super.ACTION) && (impact != super.ACTION_INFO) && (impact != super.INFO) ) { throw new IllegalArgumentException("Argument impact can be only one of ACTION, ACTION_INFO or INFO."); } this.returnOpenType = returnOpenType; } private static MBeanParameterInfo[] arrayCopyCast(OpenMBeanParameterInfo[] src) throws ArrayStoreException { MBeanParameterInfo[] dst = new MBeanParameterInfo[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 mehtod.getReturnType(). /** * Returns the open type of the values returned by the operation described by this OpenMBeanOperationInfo instance. */ public OpenType getReturnOpenType() { return returnOpenType; } /* *** Commodity methods from java.lang.Object *** */ /** * Compares the specified obj parameter with this OpenMBeanOperationInfoSupport instance for equality. *

* Returns true if and only if all of the following statements are true: *

* This ensures that this equals method works properly for obj parameters which are * different implementations of the OpenMBeanOperationInfo interface. *
  * @param obj the object to be compared for equality with this OpenMBeanOperationInfoSupport instance; * * @return true if the specified object is equal to this 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; } /** * Returns the hash code value for this OpenMBeanOperationInfoSupport instance. *

* The hash code of an OpenMBeanOperationInfoSupport instance is the sum of the hash codes * of all elements of information used in equals comparisons * (ie: its name, return open type, impact 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 OpenMBeanOperationInfoSupport instances t1 and t2, * as required by the general contract of the method * {@link Object#hashCode() Object.hashCode()}. *

* However, note that another instance of a class implementing the OpenMBeanOperationInfo interface * may be equal to this OpenMBeanOperationInfoSupport instance as defined by {@link #equals(java.lang.Object)}, * but may have a different hash code if it is calculated differently. *

* As OpenMBeanOperationInfoSupport 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. * * @return the hash code value for this 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 = new Integer(value); } // return always the same hash code for this instance (immutable) // return myHashCode.intValue(); } /** * Returns a string representation of this OpenMBeanOperationInfoSupport instance. *

* The string representation consists of the name of this class (ie javax.management.openmbean.OpenMBeanOperationInfoSupport), * and the name, signature, return open type and impact of the described operation. *

* As OpenMBeanOperationInfoSupport 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. * * @return a string representation of this 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 StringBuffer() .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(")") .toString(); } // return always the same string representation for this instance (immutable) // return myToString; } }