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Worker.javaAPI DocExample15906Thu May 23 09:32:50 BST 2002 sample.openmbean

Worker

public abstract class Worker extends Basic implements Runnable
Base class for the workers in the sample application

Fields Summary
public static final String
OBJECT_NAME
Queue
_queue
int
_workFactor
long
_numberOfUnitsProcessed
long
_totalProcessingTime
boolean
_stopCalled
boolean
_suspended
private MBeanInfo
_MBeanInfo
Constructors Summary
public Worker(Queue queue, int workFactor)
put your documentation comment here

param
Queue queue
param
int workFactor


                        
          
        super();
        _queue = queue;
        _workFactor = workFactor;
        // Attributes
        OpenMBeanAttributeInfo[] attributeInfo = new OpenMBeanAttributeInfo[6];
        attributeInfo[0] = new OpenMBeanAttributeInfoSupport(
            "WorkFactor",                 // name
            "The amount of work to do.",  // description
            SimpleType.INTEGER,           // type
            true,                         // isReadable?
            false,                        // isWritable?
            false                         // isIs?
        );
        attributeInfo[1] = new OpenMBeanAttributeInfoSupport(
            "NumberOfUnitsProcessed",     // name
            "The number of units processed.", // description
            SimpleType.LONG,              // type
            true,                         // isReadable?
            false,                        // isWritable?
            false                         // isIs?
        );
        attributeInfo[2] = new OpenMBeanAttributeInfoSupport(
            "AverageUnitProcessingTime",  // name
            "Avg. no. milliseconds to process each work unit.", // description
            SimpleType.FLOAT,             // type
            true,                         // isReadable?
            false,                        // isWritable?
            false                         // isIs?
        );
        attributeInfo[3] = new OpenMBeanAttributeInfoSupport(
            "Suspended",                  // name
            "Whether or not this thread is suspended.", // description
            SimpleType.BOOLEAN,           // type
            true,                         // isReadable?
            false,                        // isWritable?
            true                          // isIs?
        );
        attributeInfo[4] = new OpenMBeanAttributeInfoSupport(
            "TraceOn",                    // name
            "Whether or not tracing is on.", // description
            SimpleType.BOOLEAN,           // type
            true,                         // isReadable?
            false,                        // isWritable?
            true                          // isIs?
        );
        attributeInfo[5] = new OpenMBeanAttributeInfoSupport(
            "NumberOfResets",             // name
            "The number of times this MBean has been reset.", // description
            SimpleType.INTEGER,           // type
            true,                         // isReadable?
            false,                        // isWritable?
            false                         // isIs?
        );
        // Constructors
        OpenMBeanConstructorInfo[] constructorInfo = new OpenMBeanConstructorInfo[1];
        constructorInfo[0] = new OpenMBeanConstructorInfoSupport(
            "Constructor",
            "Constructs a Worker MBean.",        // description
            new OpenMBeanParameterInfoSupport[0]
        );
        // Operations
        OpenMBeanOperationInfo[] operationInfo = new OpenMBeanOperationInfo[3];
        operationInfo[0] = new OpenMBeanOperationInfoSupport(
            "stop",                        // name
            "Stops this Worker thread.",   // description
            new OpenMBeanParameterInfo[0], // signature
            SimpleType.VOID,               // return type
            MBeanOperationInfo.ACTION      // impact
        );
        operationInfo[1] = new OpenMBeanOperationInfoSupport(
            "suspend",                      // name
            "Suspends this Worker thread.", // description
            new OpenMBeanParameterInfo[0],  // signature
            SimpleType.VOID,                // return type
            MBeanOperationInfo.ACTION       // impact
        );
        operationInfo[2] = new OpenMBeanOperationInfoSupport(
            "resume",                      // name
            "Resumes this Worker thread.", // description
            new OpenMBeanParameterInfo[0], // signature
            SimpleType.VOID,               // return type
            MBeanOperationInfo.ACTION      // impact
        );
        // Notifications - NONE
        // MBeanInfo!
        _MBeanInfo = new OpenMBeanInfoSupport(
            this.getClass().getName(),  // DynamicMBean implementing class name
            "Worker Open MBean.",       // description
            attributeInfo,              // MBeanAttributeInfo[]
            constructorInfo,            // MBeanConstructorInfo[]
            operationInfo,              // MBeanOperationInfo[]
            null                        // MBeanNotificationInfo[]
        );
Methods Summary
voidcalculatePrimes(int numberOfPrimesToCalculate)
In this method is where the "work" takes place. We need a way to simulate the application doing something, so we calculate the first workFactor primes, starting with zero. So, the work factor is equal to the number of primes that are calculated.

        // There is probably an easier way to do this,
        /// but it seemed a good way to chew up some CPU
        long startTime = System.currentTimeMillis();
        long number = 1;
        int numberOfPrimesCalculated = 0;
        while (numberOfPrimesCalculated < numberOfPrimesToCalculate) {
            long currentNumber = 1;             // start with 1
            long numberOfFactors = 0;
            while (currentNumber <= number) {
                if ((number%currentNumber) == 0) {
                    // This is *definitely* the long way around, but
                    /// remember, we *want* to eat up lots of CPU...
                    numberOfFactors++;
                }
                currentNumber++;
            }
            // The number is prime if it only has two factors
            /// (i.e., itself and 1)
            if (numberOfFactors == 2) {
                numberOfPrimesCalculated++;
                //                System.out.println("Supplier.calculatePrimes(): INFO: " +
                //                    "Prime number found - " + number);
            }
            number++;
        }
        _totalProcessingTime += (System.currentTimeMillis() - startTime);
public java.lang.ObjectgetAttribute(java.lang.String attributeName)
Obtains the value of a specific attribute of the Dynamic MBean.

param
attribute The name of the attribute to be retrieved
return
The value of the attribute retrieved.
exception
AttributeNotFoundException
exception
MBeanException Wraps a java.lang.Exception thrown by the MBean's getter.
exception
ReflectionException Wraps a java.lang.Exception thrown while trying to invoke the getter.

        Object ret = null;
        //
        // Using exlicit superclass exposure as the means of
        /// management interface inheritance.
        //
        if (attributeName.equals("WorkFactor")) {
            ret = new Integer(getWorkFactor());
        } 
        else if (attributeName.equals("NumberOfUnitsProcessed")) {
            ret = new Long(getNumberOfUnitsProcessed());
        } 
        else if (attributeName.equals("AverageUnitProcessingTime")) {
            ret = new Float(getAverageUnitProcessingTime());
        } 
        else if (attributeName.equals("Suspended")) {
            ret = new Boolean(isSuspended());
        } 
        else if (attributeName.equals("TraceOn")) {
            ret = new Boolean(isTraceOn());
        } 
        else if (attributeName.equals("NumberOfResets")) {
            ret = new Integer(getNumberOfResets());
        } 
        else 
            throw  new AttributeNotFoundException("Worker.getAttribute(): ERROR: "
                    + "Attribute \'" + attributeName + "\' not found.");
        return  ret;
public javax.management.AttributeListgetAttributes(java.lang.String[] attributeNames)
Enables the values of several attributes of the Dynamic MBean.

param
attributes A list of the attributes to be retrieved.
return
The list of attributes retrieved.

        // no attributes...
        AttributeList ret = new AttributeList();
        return  ret;
public floatgetAverageUnitProcessingTime()
put your documentation comment here

return

        return  (_numberOfUnitsProcessed > 0) ? (float)_totalProcessingTime/(float)_numberOfUnitsProcessed :
                0.0f;
public javax.management.MBeanInfogetMBeanInfo()
Provides the exposed attributes and actions of the Dynamic MBean using an MBeanInfo object.

return
An instance of MBeanInfo allowing all attributes and actions exposed by this Dynamic MBean to be retrieved.

        return  (_MBeanInfo);
public longgetNumberOfUnitsProcessed()
put your documentation comment here

return

        return  _numberOfUnitsProcessed;
public intgetWorkFactor()
put your documentation comment here

return

        return  _workFactor;
public java.lang.Objectinvoke(java.lang.String operationName, java.lang.Object[] params, java.lang.String[] signature)
Allows an action to be invoked on the Dynamic MBean.

param
actionName The name of the action to be invoked.
param
params An array containing the parameters to be set when the action is invoked.
param
signature An array containing the signature of the action. The class objects will be loaded through the same class loader as the one used for loading the MBean on which the action is invoked.
return
The object returned by the action, which represents the result of invoking the action on the MBean specified.
exception
MBeanException Wraps a java.lang.Exception thrown by the MBean's invoked method.
exception
ReflectionException Wraps a 

        Object ret = Void.TYPE;
        //
        // Turn the signature into a Class array so we can get the Method
        /// object and invoke the method, passing params
        //
        try {
            Class[] sign = new Class[signature.length];
            for (int aa = 0; aa < signature.length; aa++) {
                try {
                    sign[aa] = this.getClassFromString(signature[aa]);
                } catch (ClassNotFoundException e) {
                    throw  new RuntimeOperationsException(new IllegalArgumentException(
                            "Controller.invoke(): ERROR: " + "Bad argument \'"
                            + sign[aa] + " found when attempting to invoke operation \'"
                            + operationName + "\'!"));
                }
            }
            Method theMethod = this.getClass().getMethod(operationName, sign);
            //
            // If we got this far, then the requested method is on the
            /// Class, but is it on the management interface?
            //
            if (operationName.equals("stop") || operationName.equals("suspend")
                    || operationName.equals("resume") || operationName.equals("reset")
                    || operationName.equals("enableTracing") || operationName.equals("disableTracing")) {
                theMethod.invoke(this, params);
            } 
            else {
                // delegate to parent class
                throw  new ReflectionException(new NoSuchMethodException("Worker.invoke(): ERROR: "
                        + "Method \'" + operationName + "\' does not exist."));
            }
        } catch (NoSuchMethodException e) {
            throw  new ReflectionException(e, e.getClass().getName());
        } catch (IllegalAccessException e) {
            throw  new ReflectionException(e, e.getClass().getName());
        } catch (InvocationTargetException e) {
            throw  new ReflectionException(e, e.getClass().getName());
        }
        return  ret;
public booleanisSuspended()
put your documentation comment here

return

        return  _suspended;
public voidreset()
put your documentation comment here

        setNumberOfUnitsProcessed(0);
        setNumberOfResets(getNumberOfResets() + 1);
public synchronized voidresume()
put your documentation comment here

        _suspended = false;
        notifyAll();
public abstract voidrun()
put your documentation comment here

public voidsetAttribute(javax.management.Attribute attribute)
Sets the value of a specific attribute of the Dynamic MBean
param
attribute The identification of the attribute to
be set and the value it is to be set to.
exception
AttributeNotFoundException
exception
InvalidAttributeValueException
exception
MBeanException Wraps a java.lang.Exception thrown by the MBean's setter.
exception
ReflectionException Wraps a java.lang.Exception thrown while trying to invoke the MBean's setter.
    //
    // No writeable attributes on the management interface.
    //
    
public javax.management.AttributeListsetAttributes(javax.management.AttributeList attributes)
Sets the values of several attributes of the Dynamic MBean
param
name The object name of the MBean within which the attributes are to
be set.
param
attributes A list of attributes: The identification of the
attributes to be set and the values they are to be set to.
return
The list of attributes that were set, with their new values.
        //
        // No writeable attributes on the management interface...
        //
        AttributeList ret = new AttributeList();
        return  ret;
    
public voidsetNumberOfUnitsProcessed(long value)
put your documentation comment here
param
value
        _numberOfUnitsProcessed = value;
    
public synchronized voidstop()
put your documentation comment here
        _stopCalled = true;
    
public synchronized voidsuspend()
put your documentation comment here
        _suspended = true;