https://openjdk.java.net/ 
/*
 * Copyright (c) 2000, 2017, 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.
 */
/*
 * @author    IBM Corp.
 *
 * Copyright IBM Corp. 1999-2000.  All rights reserved.
 */

package javax.management.modelmbean;

import static com.sun.jmx.defaults.JmxProperties.MODELMBEAN_LOGGER;
import com.sun.jmx.mbeanserver.GetPropertyAction;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.lang.System.Logger.Level;

import javax.management.Descriptor;
import javax.management.DescriptorAccess;
import javax.management.DescriptorKey;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanParameterInfo;
import javax.management.RuntimeOperationsException;


The ModelMBeanOperationInfo object describes a management operation of
the ModelMBean.  It is a subclass of MBeanOperationInfo with the addition
of an associated Descriptor and an implementation of the DescriptorAccess
interface.



The fields in the descriptor are defined, but not limited to, the following.
Note that when the Type in this table is Number, a String that is the decimal
representation of a Long can also be used.



ModelMBeanOperationInfo Fields

NameTypeMeaning


nameString
    Operation name.


descriptorTypeString
    Must be "operation".


classString
    Class where method is defined (fully qualified).


roleString
    Must be "operation", "getter", or "setter".


targetObjectObject
    Object on which to execute this method.


targetTypeString
    type of object reference for targetObject. Can be:
        ObjectReference | Handle | EJBHandle | IOR | RMIReference.


valueObject
    Cached value for operation.


displayNameString
    Human readable display name of the operation.

currencyTimeLimitNumber
    How long cached value is valid.


lastUpdatedTimeStampNumber
    When cached value was set.


visibilityNumber
    1-4 where 1: always visible 4: rarely visible.


presentationStringString
    XML formatted string to describe how to present operation




The default descriptor will have name, descriptorType, displayName and
role fields set.  The default value of the name and displayName fields is
the operation name.


Note: because of inconsistencies in previous versions of
this specification, it is recommended not to use negative or zero
values for currencyTimeLimit.  To indicate that a
cached value is never valid, omit the
currencyTimeLimit field.  To indicate that it is
always valid, use a very large number for this field.


The serialVersionUID of this class is 6532732096650090465L.

Since:1.5
/**
 * <p>The ModelMBeanOperationInfo object describes a management operation of
 * the ModelMBean.  It is a subclass of MBeanOperationInfo with the addition
 * of an associated Descriptor and an implementation of the DescriptorAccess
 * interface.</p>
 *
 * <P id="descriptor">
 * The fields in the descriptor are defined, but not limited to, the following.
 * Note that when the Type in this table is Number, a String that is the decimal
 * representation of a Long can also be used.</P>
 *
 * <table class="striped">
 * <caption style="display:none">ModelMBeanOperationInfo Fields</caption>
 * <tr><th>Name</th><th>Type</th><th>Meaning</th></tr>
 * <tr><td>name</td><td>String</td>
 *     <td>Operation name.</td></tr>
 * <tr><td>descriptorType</td><td>String</td>
 *     <td>Must be "operation".</td></tr>
 * <tr><td>class</td><td>String</td>
 *     <td>Class where method is defined (fully qualified).</td></tr>
 * <tr><td>role</td><td>String</td>
 *     <td>Must be "operation", "getter", or "setter".</td></tr>
 * <tr><td>targetObject</td><td>Object</td>
 *     <td>Object on which to execute this method.</td></tr>
 * <tr><td>targetType</td><td>String</td>
 *     <td>type of object reference for targetObject. Can be:
 *         ObjectReference | Handle | EJBHandle | IOR | RMIReference.</td></tr>
 * <tr><td>value</td><td>Object</td>
 *     <td>Cached value for operation.</td></tr>
 * <tr><td>displayName</td><td>String</td>
 *     <td>Human readable display name of the operation.</td>
 * <tr><td>currencyTimeLimit</td><td>Number</td>
 *     <td>How long cached value is valid.</td></tr>
 * <tr><td>lastUpdatedTimeStamp</td><td>Number</td>
 *     <td>When cached value was set.</td></tr>
 * <tr><td>visibility</td><td>Number</td>
 *     <td>1-4 where 1: always visible 4: rarely visible.</td></tr>
 * <tr><td>presentationString</td><td>String</td>
 *     <td>XML formatted string to describe how to present operation</td></tr>
 * </table>
 *
 * <p>The default descriptor will have name, descriptorType, displayName and
 * role fields set.  The default value of the name and displayName fields is
 * the operation name.</p>
 *
 * <p><b>Note:</b> because of inconsistencies in previous versions of
 * this specification, it is recommended not to use negative or zero
 * values for <code>currencyTimeLimit</code>.  To indicate that a
 * cached value is never valid, omit the
 * <code>currencyTimeLimit</code> field.  To indicate that it is
 * always valid, use a very large number for this field.</p>
 *
 * <p>The <b>serialVersionUID</b> of this class is <code>6532732096650090465L</code>.
 *
 * @since 1.5
 */

@SuppressWarnings("serial")  // serialVersionUID is not constant
public class ModelMBeanOperationInfo extends MBeanOperationInfo
         implements DescriptorAccess
{

    // Serialization compatibility stuff:
    // Two serial forms are supported in this class. The selected form depends
    // on system property "jmx.serial.form":
    //  - "1.0" for JMX 1.0
    //  - any other value for JMX 1.1 and higher
    //
    // Serial version for old serial form
    private static final long oldSerialVersionUID = 9087646304346171239L;
    //
    // Serial version for new serial form
    private static final long newSerialVersionUID = 6532732096650090465L;
    //
    // Serializable fields in old serial form
    private static final ObjectStreamField[] oldSerialPersistentFields =
    {
      new ObjectStreamField("operationDescriptor", Descriptor.class),
      new ObjectStreamField("currClass", String.class)
    };
    //
    // Serializable fields in new serial form
    private static final ObjectStreamField[] newSerialPersistentFields =
    {
      new ObjectStreamField("operationDescriptor", Descriptor.class)
    };
    //
    // Actual serial version and serial form
    private static final long serialVersionUID;
    
@serialFieldoperationDescriptor Descriptor The descriptor
containing the appropriate metadata for this instance
/**
     * @serialField operationDescriptor Descriptor The descriptor
     * containing the appropriate metadata for this instance
     */
    private static final ObjectStreamField[] serialPersistentFields;
    private static boolean compat = false;
    static {
        try {
            GetPropertyAction act = new GetPropertyAction("jmx.serial.form");
            String form = AccessController.doPrivileged(act);
            compat = (form != null && form.equals("1.0"));
        } catch (Exception e) {
            // OK: No compat with 1.0
        }
        if (compat) {
            serialPersistentFields = oldSerialPersistentFields;
            serialVersionUID = oldSerialVersionUID;
        } else {
            serialPersistentFields = newSerialPersistentFields;
            serialVersionUID = newSerialVersionUID;
        }
    }
    //
    // END Serialization compatibility stuff

        
@serialThe descriptor containing the appropriate metadata for this instance
/**
         * @serial The descriptor containing the appropriate metadata for this instance
         */
        private Descriptor operationDescriptor = validDescriptor(null);

        private static final String currClass = "ModelMBeanOperationInfo";

        
Constructs a ModelMBeanOperationInfo object with a default descriptor. The Descriptor of the constructed object will include fields contributed by any annotations on the Method object that contain the DescriptorKey meta-annotation. 
Params:
  • operationMethod – The java.lang.reflect.Method object
describing the MBean operation.
  • description – A human readable description of the operation.
/**
         * Constructs a ModelMBeanOperationInfo object with a default
         * descriptor. The {@link Descriptor} of the constructed
         * object will include fields contributed by any annotations
         * on the {@code Method} object that contain the {@link
         * DescriptorKey} meta-annotation.
         *
         * @param operationMethod The java.lang.reflect.Method object
         * describing the MBean operation.
         * @param description A human readable description of the operation.
         */

        public ModelMBeanOperationInfo(String description,
                                       Method operationMethod)
        {
                super(description, operationMethod);
                // create default descriptor
                if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                    MODELMBEAN_LOGGER.log(Level.TRACE,
                            "ModelMBeanOperationInfo(String,Method) " +
                            "Entry");
                }
                operationDescriptor = validDescriptor(null);
        }

        
Constructs a ModelMBeanOperationInfo object. The Descriptor of the constructed object will include fields contributed by any annotations on the Method object that contain the DescriptorKey meta-annotation. 
Params:
  • operationMethod – The java.lang.reflect.Method object
describing the MBean operation.
  • description – A human readable description of the
operation.
  • descriptor – An instance of Descriptor containing the
appropriate metadata for this instance of the
ModelMBeanOperationInfo.  If it is null a default
descriptor will be created. If the descriptor does not
contain the fields
"displayName" or "role", the missing ones are added with
their default values.
Throws:
  • RuntimeOperationsException – Wraps an
IllegalArgumentException. The descriptor is invalid; or
descriptor field "name" is not equal to
operation name; or descriptor field "DescriptorType" is
not equal to "operation"; or descriptor
optional field "role" is present but not equal to "operation",
"getter", or "setter".
/**
         * Constructs a ModelMBeanOperationInfo object. The {@link
         * Descriptor} of the constructed object will include fields
         * contributed by any annotations on the {@code Method} object
         * that contain the {@link DescriptorKey} meta-annotation.
         *
         * @param operationMethod The java.lang.reflect.Method object
         * describing the MBean operation.
         * @param description A human readable description of the
         * operation.
         * @param descriptor An instance of Descriptor containing the
         * appropriate metadata for this instance of the
         * ModelMBeanOperationInfo.  If it is null a default
         * descriptor will be created. If the descriptor does not
         * contain the fields
         * "displayName" or "role", the missing ones are added with
         * their default values.
         *
         * @exception RuntimeOperationsException Wraps an
         * IllegalArgumentException. The descriptor is invalid; or
         * descriptor field "name" is not equal to
         * operation name; or descriptor field "DescriptorType" is
         * not equal to "operation"; or descriptor
         * optional field "role" is present but not equal to "operation",
         * "getter", or "setter".
         *
         */

        public ModelMBeanOperationInfo(String description,
                                       Method operationMethod,
                                       Descriptor descriptor)
        {

                super(description, operationMethod);
                if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                    MODELMBEAN_LOGGER.log(Level.TRACE,
                            "ModelMBeanOperationInfo(String,Method,Descriptor) "
                            + "Entry");
                }
                operationDescriptor = validDescriptor(descriptor);
        }

        
Constructs a ModelMBeanOperationInfo object with a default descriptor.

Params:
  • name – The name of the method.
  • description – A human readable description of the operation.
  • signature – MBeanParameterInfo objects describing the
parameters(arguments) of the method.
  • type – The type of the method's return value.
  • impact – The impact of the method, one of INFO, ACTION,
ACTION_INFO, UNKNOWN.
/**
        * Constructs a ModelMBeanOperationInfo object with a default descriptor.
        *
        * @param name The name of the method.
        * @param description A human readable description of the operation.
        * @param signature MBeanParameterInfo objects describing the
        * parameters(arguments) of the method.
        * @param type The type of the method's return value.
        * @param impact The impact of the method, one of INFO, ACTION,
        * ACTION_INFO, UNKNOWN.
        */

        public ModelMBeanOperationInfo(String name,
                                       String description,
                                       MBeanParameterInfo[] signature,
                                       String type,
                                       int impact)
        {

                super(name, description, signature, type, impact);
                // create default descriptor
                if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                    MODELMBEAN_LOGGER.log(Level.TRACE,
                            "ModelMBeanOperationInfo(" +
                            "String,String,MBeanParameterInfo[],String,int) " +
                            "Entry");
                }
                operationDescriptor = validDescriptor(null);
        }

        
Constructs a ModelMBeanOperationInfo object.

Params:
  • name – The name of the method.
  • description – A human readable description of the operation.
  • signature – MBeanParameterInfo objects describing the
parameters(arguments) of the method.
  • type – The type of the method's return value.
  • impact – The impact of the method, one of INFO, ACTION,
ACTION_INFO, UNKNOWN.
  • descriptor – An instance of Descriptor containing the
appropriate metadata for this instance of the
MBeanOperationInfo. If it is null then a default descriptor
will be created.  If the descriptor does not contain
fields "displayName" or "role",
the missing ones are added with their default values.
Throws:
  • RuntimeOperationsException – Wraps an
IllegalArgumentException. The descriptor is invalid; or
descriptor field "name" is not equal to
operation name; or descriptor field "DescriptorType" is
not equal to "operation"; or descriptor optional
field "role" is present but not equal to "operation", "getter", or
"setter".
/**
        * Constructs a ModelMBeanOperationInfo object.
        *
        * @param name The name of the method.
        * @param description A human readable description of the operation.
        * @param signature MBeanParameterInfo objects describing the
        * parameters(arguments) of the method.
        * @param type The type of the method's return value.
        * @param impact The impact of the method, one of INFO, ACTION,
        * ACTION_INFO, UNKNOWN.
        * @param descriptor An instance of Descriptor containing the
        * appropriate metadata for this instance of the
        * MBeanOperationInfo. If it is null then a default descriptor
        * will be created.  If the descriptor does not contain
        * fields "displayName" or "role",
        * the missing ones are added with their default values.
        *
        * @exception RuntimeOperationsException Wraps an
        * IllegalArgumentException. The descriptor is invalid; or
        * descriptor field "name" is not equal to
        * operation name; or descriptor field "DescriptorType" is
        * not equal to "operation"; or descriptor optional
        * field "role" is present but not equal to "operation", "getter", or
        * "setter".
        */

        public ModelMBeanOperationInfo(String name,
                                       String description,
                                       MBeanParameterInfo[] signature,
                                       String type,
                                       int impact,
                                       Descriptor descriptor)
        {
                super(name, description, signature, type, impact);
                if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                    MODELMBEAN_LOGGER.log(Level.TRACE,
                            "ModelMBeanOperationInfo(String,String," +
                            "MBeanParameterInfo[],String,int,Descriptor) " +
                            "Entry");
                }
                operationDescriptor = validDescriptor(descriptor);
        }

        
Constructs a new ModelMBeanOperationInfo object from this
ModelMBeanOperation Object.

Params:
  • inInfo – the ModelMBeanOperationInfo to be duplicated
/**
         * Constructs a new ModelMBeanOperationInfo object from this
         * ModelMBeanOperation Object.
         *
         * @param inInfo the ModelMBeanOperationInfo to be duplicated
         *
         */

        public ModelMBeanOperationInfo(ModelMBeanOperationInfo inInfo)
        {
                super(inInfo.getName(),
                          inInfo.getDescription(),
                          inInfo.getSignature(),
                          inInfo.getReturnType(),
                          inInfo.getImpact());
                if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                    MODELMBEAN_LOGGER.log(Level.TRACE,
                            "ModelMBeanOperationInfo(ModelMBeanOperationInfo)" +
                            "Entry");
                }
                Descriptor newDesc = inInfo.getDescriptor();
                operationDescriptor = validDescriptor(newDesc);
        }

        
Creates and returns a new ModelMBeanOperationInfo which is a
duplicate of this ModelMBeanOperationInfo.

/**
        * Creates and returns a new ModelMBeanOperationInfo which is a
        * duplicate of this ModelMBeanOperationInfo.
        *
        */

        public Object clone ()
        {
            if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                MODELMBEAN_LOGGER.log(Level.TRACE, "Entry");
            }
                return(new ModelMBeanOperationInfo(this)) ;
        }

        
Returns a copy of the associated Descriptor of the
ModelMBeanOperationInfo.

See Also:
Returns:Descriptor associated with the
ModelMBeanOperationInfo object.
/**
         * Returns a copy of the associated Descriptor of the
         * ModelMBeanOperationInfo.
         *
         * @return Descriptor associated with the
         * ModelMBeanOperationInfo object.
         *
         * @see #setDescriptor
         */

        public Descriptor getDescriptor()
        {
            if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                MODELMBEAN_LOGGER.log(Level.TRACE, "Entry");
            }
            if (operationDescriptor == null) {
                operationDescriptor = validDescriptor(null);
            }

            return((Descriptor) operationDescriptor.clone());
        }

        
Sets associated Descriptor (full replace) for the
ModelMBeanOperationInfo If the new Descriptor is null, then
the associated Descriptor reverts to a default descriptor.
The Descriptor is validated before it is assigned.  If the
new Descriptor is invalid, then a
RuntimeOperationsException wrapping an
IllegalArgumentException is thrown.

Params:
  • inDescriptor – replaces the Descriptor associated with the
ModelMBeanOperation.
Throws:
See Also:
/**
         * Sets associated Descriptor (full replace) for the
         * ModelMBeanOperationInfo If the new Descriptor is null, then
         * the associated Descriptor reverts to a default descriptor.
         * The Descriptor is validated before it is assigned.  If the
         * new Descriptor is invalid, then a
         * RuntimeOperationsException wrapping an
         * IllegalArgumentException is thrown.
         *
         * @param inDescriptor replaces the Descriptor associated with the
         * ModelMBeanOperation.
         *
         * @exception RuntimeOperationsException Wraps an
         * IllegalArgumentException for invalid Descriptor.
         *
         * @see #getDescriptor
         */
        public void setDescriptor(Descriptor inDescriptor)
        {
            if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                MODELMBEAN_LOGGER.log(Level.TRACE, "Entry");
            }
            operationDescriptor = validDescriptor(inDescriptor);
        }

        
Returns a string containing the entire contents of the
ModelMBeanOperationInfo in human readable form.

/**
        * Returns a string containing the entire contents of the
        * ModelMBeanOperationInfo in human readable form.
        */
        public String toString()
        {
            if (MODELMBEAN_LOGGER.isLoggable(Level.TRACE)) {
                MODELMBEAN_LOGGER.log(Level.TRACE, "Entry");
            }
                String retStr =
                    "ModelMBeanOperationInfo: " + this.getName() +
                    " ; Description: " + this.getDescription() +
                    " ; Descriptor: " + this.getDescriptor() +
                    " ; ReturnType: " + this.getReturnType() +
                    " ; Signature: ";
                MBeanParameterInfo[] pTypes = this.getSignature();
                for (int i=0; i < pTypes.length; i++)
                {
                        retStr = retStr.concat((pTypes[i]).getType() + ", ");
                }
                return retStr;
        }

        
Clones the passed in Descriptor, sets default values, and checks for validity.
If the Descriptor is invalid (for instance by having the wrong "name"),
this indicates programming error and a RuntimeOperationsException will be thrown.
The following fields will be defaulted if they are not already set:
displayName=this.getName(),name=this.getName(),
descriptorType="operation", role="operation"

Params:
  • in – Descriptor to be checked, or null which is equivalent to
an empty Descriptor.
Throws:
/**
         * Clones the passed in Descriptor, sets default values, and checks for validity.
         * If the Descriptor is invalid (for instance by having the wrong "name"),
         * this indicates programming error and a RuntimeOperationsException will be thrown.
         *
         * The following fields will be defaulted if they are not already set:
         * displayName=this.getName(),name=this.getName(),
         * descriptorType="operation", role="operation"
         *
         *
         * @param in Descriptor to be checked, or null which is equivalent to
         * an empty Descriptor.
         * @exception RuntimeOperationsException if Descriptor is invalid
         */
        private Descriptor validDescriptor(final Descriptor in)
        throws RuntimeOperationsException {
            Descriptor clone;
            boolean defaulted = (in == null);
            if (defaulted) {
                clone = new DescriptorSupport();
                MODELMBEAN_LOGGER.log(Level.TRACE, "Null Descriptor, creating new.");
            } else {
                clone = (Descriptor) in.clone();
            }

            //Setting defaults.
            if (defaulted && clone.getFieldValue("name")==null) {
                clone.setField("name", this.getName());
                MODELMBEAN_LOGGER.log(Level.TRACE, "Defaulting Descriptor name to " + this.getName());
            }
            if (defaulted && clone.getFieldValue("descriptorType")==null) {
                clone.setField("descriptorType", "operation");
                MODELMBEAN_LOGGER.log(Level.TRACE, "Defaulting descriptorType to \"operation\"");
            }
            if (clone.getFieldValue("displayName") == null) {
                clone.setField("displayName",this.getName());
                MODELMBEAN_LOGGER.log(Level.TRACE, "Defaulting Descriptor displayName to " + this.getName());
            }
            if (clone.getFieldValue("role") == null) {
                clone.setField("role","operation");
                MODELMBEAN_LOGGER.log(Level.TRACE, "Defaulting Descriptor role field to \"operation\"");
            }

            //Checking validity
            if (!clone.isValid()) {
                 throw new RuntimeOperationsException(new IllegalArgumentException("Invalid Descriptor argument"),
                    "The isValid() method of the Descriptor object itself returned false,"+
                    "one or more required fields are invalid. Descriptor:" + clone.toString());
            }
            if (!getName().equalsIgnoreCase((String) clone.getFieldValue("name"))) {
                    throw new RuntimeOperationsException(new IllegalArgumentException("Invalid Descriptor argument"),
                    "The Descriptor \"name\" field does not match the object described. " +
                     " Expected: "+ this.getName() + " , was: " + clone.getFieldValue("name"));
            }
            if (!"operation".equalsIgnoreCase((String) clone.getFieldValue("descriptorType"))) {
                     throw new RuntimeOperationsException(new IllegalArgumentException("Invalid Descriptor argument"),
                    "The Descriptor \"descriptorType\" field does not match the object described. " +
                     " Expected: \"operation\" ," + " was: " + clone.getFieldValue("descriptorType"));
            }
            final String role = (String)clone.getFieldValue("role");
            if (!(role.equalsIgnoreCase("operation") ||
                  role.equalsIgnoreCase("setter") ||
                  role.equalsIgnoreCase("getter"))) {
                     throw new RuntimeOperationsException(new IllegalArgumentException("Invalid Descriptor argument"),
                    "The Descriptor \"role\" field does not match the object described. " +
                     " Expected: \"operation\", \"setter\", or \"getter\" ," + " was: " + clone.getFieldValue("role"));
            }
            final Object targetValue = clone.getFieldValue("targetType");
            if (targetValue != null) {
                if (!(targetValue instanceof java.lang.String)) {
                    throw new RuntimeOperationsException(new IllegalArgumentException("Invalid Descriptor argument"),
                    "The Descriptor field \"targetValue\" is invalid class. " +
                     " Expected: java.lang.String, " + " was: " + targetValue.getClass().getName());
                }
            }
            return clone;
        }

    /**
     * Deserializes a {@link ModelMBeanOperationInfo} from an {@link ObjectInputStream}.
     */
    private void readObject(ObjectInputStream in)
            throws IOException, ClassNotFoundException {
      // New serial form ignores extra field "currClass"
      in.defaultReadObject();
    }


    /**
     * Serializes a {@link ModelMBeanOperationInfo} to an {@link ObjectOutputStream}.
     */
    private void writeObject(ObjectOutputStream out)
            throws IOException {
      if (compat)
      {
        // Serializes this instance in the old serial form
        //
        ObjectOutputStream.PutField fields = out.putFields();
        fields.put("operationDescriptor", operationDescriptor);
        fields.put("currClass", currClass);
        out.writeFields();
      }
      else
      {
        // Serializes this instance in the new serial form
        //
        out.defaultWriteObject();
      }
    }

}