simpledynamic.java

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        AttributeList resultList = new AttributeList();

        // If attributeNames is empty, nothing more to do
        //
        if (attributes.isEmpty())
            return resultList;

        // For each attribute, try to set it and add to the result list if
        // successfull
        //
        for (Iterator i = attributes.iterator(); i.hasNext();) {
            Attribute attr = (Attribute) i.next();
            try {
                setAttribute(attr);
                String name = attr.getName();
                Object value = getAttribute(name); 
                resultList.add(new Attribute(name,value));
            } catch(Exception e) {
                e.printStackTrace();
            }
        }
        return resultList;
    }

    /**
     * Allows an operation to be invoked on the Dynamic MBean.
     */
    public Object invoke(String operationName,
                         Object params[],
                         String signature[])
        throws MBeanException, ReflectionException {

        // Check operationName is not null to avoid NullPointerException
        // later on
        //
        if (operationName == null) {
            throw new RuntimeOperationsException(
                 new IllegalArgumentException("Operation name cannot be null"), 
                 "Cannot invoke a null operation in " + dClassName);
        }
        // Check for a recognized operation name and call the corresponding
        // operation
        //
        if (operationName.equals("reset")) {
            reset();
            return null;
        } else { 
            // Unrecognized operation name
            //
            throw new ReflectionException(
                                new NoSuchMethodException(operationName), 
                                "Cannot find the operation " + operationName +
                                " in " + dClassName);
        }
    }

    /**
     * This method provides the exposed attributes and operations of the
     * Dynamic MBean. It provides this information using an MBeanInfo object.
     */
    public MBeanInfo getMBeanInfo() {

        // Return the information we want to expose for management:
        // the dMBeanInfo private field has been built at instanciation time
        //
        return dMBeanInfo;
    }

    /*
     * -----------------------------------------------------
     * OTHER PUBLIC METHODS
     * -----------------------------------------------------
     */

    /**
     * Getter: get the "State" attribute of the "SimpleDynamic" dynamic MBean.
     */
    public String getState() {
        return state;
    }

    /** 
     * Setter: set the "State" attribute of the "SimpleDynamic" dynamic MBean.
     */
    public void setState(String s) {
        state = s;
        nbChanges++;
    }

    /**
     * Getter: get the "NbChanges" attribute of the "SimpleDynamic" dynamic
     * MBean.
     */
    public Integer getNbChanges() {
        return new Integer(nbChanges);
    }

    /**
     * Operation: reset to their initial values the "State" and "NbChanges" 
     * attributes of the "SimpleDynamic" dynamic MBean. 
     */
    public void reset() {
        AttributeChangeNotification acn =
            new AttributeChangeNotification(this,
                                            0,
                                            0,
                                            "NbChanges reset",
                                            "NbChanges",
                                            "Integer",
                                            new Integer(nbChanges),
                                            new Integer(0));
        state = "initial state";
        nbChanges = 0;
        nbResets++;
        sendNotification(acn);
    }

    /**
     * Return the "NbResets" property. 
     * This method is not a Getter in the JMX sense because 
     * it is not returned by the getMBeanInfo() method.
     */
    public Integer getNbResets() {
        return new Integer(nbResets);
    }

    /*
     * -----------------------------------------------------
     * PRIVATE METHODS
     * -----------------------------------------------------
     */
  
    /**
     * Build the private dMBeanInfo field,
     * which represents the management interface exposed by the MBean,
     * that is, the set of attributes, constructors, operations and
     * notifications which are available for management. 
     *
     * A reference to the dMBeanInfo object is returned by the getMBeanInfo()
     * method of the DynamicMBean interface. Note that, once constructed, an
     * MBeanInfo object is immutable.
     */
    private void buildDynamicMBeanInfo() {

        dAttributes[0] =
            new MBeanAttributeInfo("State",
                                   "java.lang.String",
                                   "State string.",
                                   true,
                                   true,
                                   false);
        dAttributes[1] =
            new MBeanAttributeInfo("NbChanges",
                                   "java.lang.Integer",
                                   "Number of times the " +
                                   "State string has been changed.",
                                   true,
                                   false,
                                   false);

        Constructor[] constructors = this.getClass().getConstructors();
        dConstructors[0] =
            new MBeanConstructorInfo("Constructs a " +
                                     "SimpleDynamic object",
                                     constructors[0]);

        MBeanParameterInfo[] params = null;
        dOperations[0] =
            new MBeanOperationInfo("reset",
                                   "reset State and NbChanges " +
                                   "attributes to their initial values",
                                   params , 
                                   "void", 
                                   MBeanOperationInfo.ACTION);

        dNotifications[0] =
            new MBeanNotificationInfo(
            new String[] { AttributeChangeNotification.ATTRIBUTE_CHANGE },
            AttributeChangeNotification.class.getName(),
            "This notification is emitted when the reset() method is called.");

        dMBeanInfo = new MBeanInfo(dClassName,
                                   dDescription,
                                   dAttributes,
                                   dConstructors,
                                   dOperations,
                                   dNotifications);
    }

    /*
     * -----------------------------------------------------
     * PRIVATE VARIABLES
     * -----------------------------------------------------
     */

    private String state = "initial state";
    private int nbChanges = 0;
    private int nbResets = 0;

    private String dClassName = this.getClass().getName();
    private String dDescription = "Simple implementation of a dynamic MBean.";

    private MBeanAttributeInfo[] dAttributes =
        new MBeanAttributeInfo[2];
    private MBeanConstructorInfo[] dConstructors =
        new MBeanConstructorInfo[1];
    private MBeanNotificationInfo[] dNotifications =
        new MBeanNotificationInfo[1];
    private MBeanOperationInfo[] dOperations =
        new MBeanOperationInfo[1];
    private MBeanInfo dMBeanInfo = null;
}