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Basic.javaAPI DocExample13628Thu May 23 09:32:50 BST 2002 sample.dynamic

Basic

public abstract class Basic extends Object implements DynamicMBean
Base class for the sample application. Implemented as a dynamic MBean. There are three attributes: 1. NumberOfResets (int) 2. TraceOn (boolean) 3. DebugOn (boolean) and five operations: 1. enableTracing() 2. disableTracing() 3. enableDebugging() 4. disableDebugging() 5. reset() (abstract - must be implemented by subclasses)
author
Steve Perry

Fields Summary
private int
_numberOfResets
private boolean
_traceOn
private boolean
_debugOn
private MBeanInfo
_MBeanInfo
Constructors Summary
public Basic()
Construtor, used to expose the management interface of this MBean through the dynamic MBean metadata classes.

        //
        // Build attribute metadata:
        // - NumberOfResets
        // - TraceOn
        // - DebugOn
        //
        MBeanAttributeInfo[] attributeInfo = new MBeanAttributeInfo[3];
        // - NumberOfResets
        attributeInfo[0] = new MBeanAttributeInfo(
            "NumberOfResets",       // name
            Integer.TYPE.getName(), // type
            "The number of times reset() has been called.",         // description
            true,                   // isReadable
            false,                  // isWriteable
            false);                 // isIs
        // - TraceOn
        attributeInfo[1] = new MBeanAttributeInfo(
            "TraceOn",              // name
            Boolean.TYPE.getName(), // type
            "Indicates whether or not tracing is on.",              // description
            true,                   // isReadable
            false,                  // isWriteable
            true);                  // isIs
        // - DebugOn
        attributeInfo[2] = new MBeanAttributeInfo(
            "DebugOn",              // name
            Boolean.TYPE.getName(), // type
            "Indicates whether or not debugging is on.",            // description
            true,                   // isReadable
            false,                  // isWriteable
            true);                  // isIs
        //
        // Now build Constructor metadata
        //
        Constructor[] constructors = this.getClass().getConstructors();
        MBeanConstructorInfo[] constructorInfo = new MBeanConstructorInfo[constructors.length];
        for (int aa = 0; aa < constructors.length; aa++) {
            constructorInfo[aa] = new MBeanConstructorInfo("Constructs a Basic MBean.",         // description
            constructors[aa]                    // java.lang.reflect.Constructor
            );
        }
        //
        // Now build operation metadata:
        // - enableTracing
        // - disableTracing
        // - enableDebugging
        // - disableDebugging
        // - reset
        //
        MBeanParameterInfo[] voidSignature = null;
        MBeanOperationInfo[] operationInfo = new MBeanOperationInfo[5];
        // - enableTracing
        operationInfo[0] = new MBeanOperationInfo(
            "enableTracing",            // name
            "Turns tracing on.",        // description
            voidSignature,              // MBeanParameterInfo[]
            Void.TYPE.getName(),        // type
            MBeanOperationInfo.ACTION   // impact
        );
        // - disableTracing
        operationInfo[1] = new MBeanOperationInfo(
            "disableTracing",           // name
            "Turns tracing off.",       // description
            voidSignature,              // MBeanParameterInfo[]
            Void.TYPE.getName(),        // type
            MBeanOperationInfo.ACTION   // impact
        );
        // - enableDebugging
        operationInfo[2] = new MBeanOperationInfo(
            "enableDebugging",          // name
            "Turns debugging on.",      // description
            voidSignature,              // MBeanParameterInfo[]
            Void.TYPE.getName(),        // type
            MBeanOperationInfo.ACTION   // impact
        );
        // - disableDebugging
        operationInfo[3] = new MBeanOperationInfo(
            "disableDebugging",         // name
            "Turns debugging off.",     // description
            voidSignature,              // MBeanParameterInfo[]
            Void.TYPE.getName(),        // type
            MBeanOperationInfo.ACTION   // impact
        );
        // - reset
        operationInfo[4] = new MBeanOperationInfo(
            "reset",                    // name
            "Resets the state of this MBean.",      // description
            voidSignature,              // MBeanParameterInfo[]
            Void.TYPE.getName(),        // type
            MBeanOperationInfo.ACTION   // impact
        );
        //
        // Build Notification Metadata:
        // - none
        //
        MBeanNotificationInfo[] notificationInfo = new MBeanNotificationInfo[0];
        //
        // Now (finally!) create the MBean info metadata object
        //
        _MBeanInfo = new MBeanInfo(
            this.getClass().getName(),  // DynamicMBean implementing class name
            "Basic Dynamic MBean.",     // description
            attributeInfo,              // MBeanAttributeInfo[]
            constructorInfo,            // MBeanConstructorInfo[]
            operationInfo,              // MBeanOperationInfo[]
            notificationInfo            // MBeanNotificationInfo[]
        );
Methods Summary
public voiddisableDebugging()

        _debugOn = false;
public voiddisableTracing()

        _traceOn = false;
public voidenableDebugging()

        _debugOn = true;
public voidenableTracing()

        _traceOn = true;
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;
        //
        // See if attribute is recognized.
        //
        if (attributeName.equals("NumberOfResets")) {
            ret = new Integer(getNumberOfResets());
        } 
        else if (attributeName.equals("TraceOn")) {
            ret = new Boolean(isTraceOn());
        } 
        else if (attributeName.equals("DebugOn")) {
            ret = new Boolean(isDebugOn());
        } 
        // If attribute_name has not been recognized throw an AttributeNotFoundException
        else 
            throw  new AttributeNotFoundException("Basic.getAttribute(): ERROR: "
                    + "Cannot find " + attributeName + " attribute.");
        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.

        AttributeList resultList = new AttributeList();
        for (int aa = 0; aa < attributeNames.length; aa++) {
            try {
                Object value = getAttribute((String)attributeNames[aa]);
                resultList.add(new Attribute(attributeNames[aa], value));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return  resultList;
java.lang.ClassgetClassFromString(java.lang.String className)
Helper method. Takes the string representation of a class and returns the corresponding Class object.

        Class ret = null;
        if (className.equals(Boolean.TYPE.getName()))
            ret = Boolean.TYPE; 
        else if (className.equals(Character.TYPE.getName()))
            ret = Character.TYPE; 
        else if (className.equals(Byte.TYPE.getName()))
            ret = Byte.TYPE; 
        else if (className.equals(Short.TYPE.getName()))
            ret = Short.TYPE; 
        else if (className.equals(Integer.TYPE.getName()))
            ret = Integer.TYPE; 
        else if (className.equals(Long.TYPE.getName()))
            ret = Long.TYPE; 
        else if (className.equals(Float.TYPE.getName()))
            ret = Float.TYPE; 
        else if (className.equals(Double.TYPE.getName()))
            ret = Double.TYPE; 
        else if (className.equals(Void.TYPE.getName()))
            ret = Void.TYPE;
        //
        // Not a primitive type, just load the class based
        /// on the name.
        //
        else 
            ret = Class.forName(className);
        return  ret;
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 intgetNumberOfResets()

        return  _numberOfResets;
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;
        // Check for a recognized operation name and call the corresponding operation
        if (operationName.equals("enableTracing")) {
            enableTracing();
        } 
        else if (operationName.equals("disableTracing")) {
            disableTracing();
        } 
        else if (operationName.equals("enableDebugging")) {
            enableDebugging();
        } 
        else if (operationName.equals("disableDebugging")) {
            disableDebugging();
        } 
        else if (operationName.equals("reset")) {
            reset();
        } 
        else {
            // unrecognized operation name:
            throw  new ReflectionException(new NoSuchMethodException(operationName), 
                    "Basic.invoke(): ERROR: " + "Cannot find the operation "
                    + operationName + "!");
        }
        return  ret;
public booleanisDebugOn()

        return  _debugOn;
public booleanisTraceOn()

        return  _traceOn;
public abstract voidreset()

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.
    /// Nothing to do.
    //
    
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...
        /// Return an empty AttributeList.
        //
        AttributeList atts = new AttributeList();
        return  atts;
    
public voidsetNumberOfResets(int value)
        _numberOfResets = value;