org.apache.felix.mosgi.jmx.agent.mx4j
Class AbstractDynamicMBean

java.lang.Object
  org.apache.felix.mosgi.jmx.agent.mx4j.AbstractDynamicMBean

All Implemented Interfaces:

javax.management.DynamicMBean

public abstract class AbstractDynamicMBean
extends Object
implements javax.management.DynamicMBean

Utility class that allow the user to easily write DynamicMBeans.
By extending this class, the developer does not have to implement the methods of the DynamicMBean interface, but has instead to provide only the metadata (by overriding few methods) and the implementation (by implementing the methods) of the MBean itself.
The methods to override that provides metadata information are usually the following:

• createMBeanAttributeInfo, if the MBeans has manageable attributes
• createMBeanOperationInfo, if the MBeans has manageable operations
• createMBeanNotificationInfo, if the MBeans has manageable notifications
• createMBeanConstructorInfo, if the MBeans has manageable constructors
• getMBeanDescription

For example, the following MBean only has one manageable attribute:

 public class SimpleDynamic extends AbstractDynamicMBean
 {
    protected MBeanAttributeInfo[] createMBeanAttributeInfo()
    {
       return new MBeanAttributeInfo[]
       {
          new MBeanAttributeInfo("Name", String.class.getName(), "The name", true, true, false)
       };
    }

    protected String getMBeanDescription()
    {
       return "A simple DynamicMBean";
    }

    public String getName() { ... }

    public void setName(String name) { ... }
 }
 

It is responsibility of the developer to specify the metadata and implement the methods specified by the metadata, that will be invoked via reflection by the AbstractDynamicMBean class. For this reason, the methods belonging to the MBean implementation (in the case above getName() and setName(...)) must be public.

Version:

$Revision: 1.1.1.1 $

Author:

Simone Bordet

Constructor Summary

protected

AbstractDynamicMBean() Only subclasses can create a new instance of an AbstractDynamicMBean.

Method Summary

protected javax.management.MBeanAttributeInfo[]	createMBeanAttributeInfo() To be overridden to return metadata information about manageable attributes.
protected javax.management.MBeanConstructorInfo[]	createMBeanConstructorInfo() To be overridden to return metadata information about manageable constructors.
protected javax.management.MBeanInfo	createMBeanInfo() Creates the MBeanInfo for this instance, calling in succession factory methods that the user can override.
protected javax.management.MBeanNotificationInfo[]	createMBeanNotificationInfo() To be overridden to return metadata information about manageable notifications.
protected javax.management.MBeanOperationInfo[]	createMBeanOperationInfo() To be overridden to return metadata information about manageable operations.
protected Method	findMethod(Class cls, String name, Class[] params) Returns the (public) method with the given name and signature on the given class.
Object	getAttribute(String attribute) Returns the value of the manageable attribute, as specified by the DynamicMBean interface.
javax.management.AttributeList	getAttributes(String[] attributes) Returns the manageable attributes, as specified by the DynamicMBean interface.
protected String	getMBeanClassName() To be overridden to return metadata information about the class name of this MBean; by default returns this class' name.
protected String	getMBeanDescription() To be overridden to return metadata information about the description of this MBean.
javax.management.MBeanInfo	getMBeanInfo() Returns the MBeaInfo, as specified by the DynamicMBean interface; the default implementation caches the value returned by createMBeanInfo() (that is thus called only once).
protected Object	getResource() Returns the resource object on which invoke attribute's getters, attribute's setters and operation's methods
protected Object	invoke(Object resource, String name, Class[] params, Object[] args) Looks up the method to call on given resource and invokes it.
protected Object	invoke(String name, Class[] params, Object[] args) Deprecated. Replaced by invoke(Object,String,Class[],Object[]). The resource passed is the resource as set by setResource(java.lang.Object) or - if it is null - 'this' instance. This method is deprecated because it is not thread safe.
Object	invoke(String method, Object[] arguments, String[] params) Returns the value of the manageable operation as specified by the DynamicMBean interface
protected Object	invokeMethod(Method method, Object resource, Object[] args) Invokes the given method on the given resource object with the given arguments.
void	setAttribute(javax.management.Attribute attribute) Sets the value of the manageable attribute, as specified by the DynamicMBean interface.
javax.management.AttributeList	setAttributes(javax.management.AttributeList attributes) Sets the manageable attributes, as specified by the DynamicMBean interface.
protected void	setMBeanInfo(javax.management.MBeanInfo info) Sets the MBeanInfo object cached by this instance.
void	setResource(Object resource) Specifies the resource object on which invoke attribute's getters, attribute's setters and operation's methods.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractDynamicMBean

protected AbstractDynamicMBean()

Only subclasses can create a new instance of an AbstractDynamicMBean.

See Also:

createMBeanConstructorInfo()

Method Detail

getAttribute

public Object getAttribute(String attribute)
                    throws javax.management.AttributeNotFoundException,
                           javax.management.MBeanException,
                           javax.management.ReflectionException

Returns the value of the manageable attribute, as specified by the DynamicMBean interface.

Specified by:

getAttribute in interface javax.management.DynamicMBean

Throws:

javax.management.AttributeNotFoundException

javax.management.MBeanException

javax.management.ReflectionException

See Also:

createMBeanAttributeInfo()

getAttributes

public javax.management.AttributeList getAttributes(String[] attributes)

Returns the manageable attributes, as specified by the DynamicMBean interface.

Specified by:

getAttributes in interface javax.management.DynamicMBean

getMBeanInfo

public javax.management.MBeanInfo getMBeanInfo()

Returns the MBeaInfo, as specified by the DynamicMBean interface; the default implementation caches the value returned by createMBeanInfo() (that is thus called only once).

Specified by:

getMBeanInfo in interface javax.management.DynamicMBean

See Also:

createMBeanInfo(), setMBeanInfo(javax.management.MBeanInfo)

invoke

public Object invoke(String method,
                     Object[] arguments,
                     String[] params)
              throws javax.management.MBeanException,
                     javax.management.ReflectionException

Returns the value of the manageable operation as specified by the DynamicMBean interface

Specified by:

invoke in interface javax.management.DynamicMBean

Throws:

javax.management.MBeanException

javax.management.ReflectionException

See Also:

createMBeanOperationInfo()

setAttribute

public void setAttribute(javax.management.Attribute attribute)
                  throws javax.management.AttributeNotFoundException,
                         javax.management.InvalidAttributeValueException,
                         javax.management.MBeanException,
                         javax.management.ReflectionException

Sets the value of the manageable attribute, as specified by the DynamicMBean interface.

Specified by:

setAttribute in interface javax.management.DynamicMBean

Throws:

javax.management.AttributeNotFoundException

javax.management.InvalidAttributeValueException

javax.management.MBeanException

javax.management.ReflectionException

See Also:

createMBeanAttributeInfo()

setAttributes

public javax.management.AttributeList setAttributes(javax.management.AttributeList attributes)

Sets the manageable attributes, as specified by the DynamicMBean interface.

Specified by:

setAttributes in interface javax.management.DynamicMBean

invoke

protected Object invoke(String name,
                        Class[] params,
                        Object[] args)
                 throws javax.management.InvalidAttributeValueException,
                        javax.management.MBeanException,
                        javax.management.ReflectionException

Deprecated. Replaced by invoke(Object,String,Class[],Object[]).
The resource passed is the resource as set by setResource(java.lang.Object) or - if it is null - 'this' instance.
This method is deprecated because it is not thread safe.

Throws:

javax.management.InvalidAttributeValueException

javax.management.MBeanException

javax.management.ReflectionException

invoke

protected Object invoke(Object resource,
                        String name,
                        Class[] params,
                        Object[] args)
                 throws javax.management.InvalidAttributeValueException,
                        javax.management.MBeanException,
                        javax.management.ReflectionException

Looks up the method to call on given resource and invokes it. The default implementation requires that the methods that implement attribute and operation behavior on the resource object are public, but it is possible to override this behavior, and call also private methods.

Throws:

javax.management.InvalidAttributeValueException

javax.management.MBeanException

javax.management.ReflectionException

See Also:

findMethod(java.lang.Class, java.lang.String, java.lang.Class[]), invokeMethod(java.lang.reflect.Method, java.lang.Object, java.lang.Object[])

findMethod

protected Method findMethod(Class cls,
                            String name,
                            Class[] params)
                     throws NoSuchMethodException

Returns the (public) method with the given name and signature on the given class.
Override to return non-public methods, or to map methods to other classes, or to map methods with different signatures

Throws:

NoSuchMethodException

See Also:

invoke(String, Class[], Object[]), invokeMethod(java.lang.reflect.Method, java.lang.Object, java.lang.Object[])

invokeMethod

protected Object invokeMethod(Method method,
                              Object resource,
                              Object[] args)
                       throws IllegalAccessException,
                              IllegalArgumentException,
                              InvocationTargetException

Invokes the given method on the given resource object with the given arguments.
Override to map methods to other objects, or to map methods with different arguments

Throws:

IllegalAccessException

IllegalArgumentException

InvocationTargetException

See Also:

invoke(String, Class[], Object[]), findMethod(java.lang.Class, java.lang.String, java.lang.Class[])

getResource

protected Object getResource()

Returns the resource object on which invoke attribute's getters, attribute's setters and operation's methods

See Also:

setResource(java.lang.Object)

setResource

public void setResource(Object resource)

Specifies the resource object on which invoke attribute's getters, attribute's setters and operation's methods.

See Also:

getResource()

setMBeanInfo

protected void setMBeanInfo(javax.management.MBeanInfo info)

Sets the MBeanInfo object cached by this instance.
The given MBeanInfo is not cloned.

See Also:

getMBeanInfo()

createMBeanInfo

protected javax.management.MBeanInfo createMBeanInfo()

Creates the MBeanInfo for this instance, calling in succession factory methods that the user can override. Information to create MBeanInfo are taken calling the following methods:

• createMBeanAttributeInfo()
• createMBeanConstructorInfo()
• createMBeanOperationInfo()
• createMBeanNotificationInfo()
• getMBeanClassName()
• getMBeanDescription()

createMBeanAttributeInfo

protected javax.management.MBeanAttributeInfo[] createMBeanAttributeInfo()

To be overridden to return metadata information about manageable attributes.

createMBeanConstructorInfo

protected javax.management.MBeanConstructorInfo[] createMBeanConstructorInfo()

To be overridden to return metadata information about manageable constructors.

createMBeanOperationInfo

protected javax.management.MBeanOperationInfo[] createMBeanOperationInfo()

To be overridden to return metadata information about manageable operations.

createMBeanNotificationInfo

protected javax.management.MBeanNotificationInfo[] createMBeanNotificationInfo()

To be overridden to return metadata information about manageable notifications.

getMBeanClassName

protected String getMBeanClassName()

To be overridden to return metadata information about the class name of this MBean; by default returns this class' name.

getMBeanDescription

protected String getMBeanDescription()

To be overridden to return metadata information about the description of this MBean.