DynamicMBean, MBeanRegistration
StandardEmitterMBeanpublic class StandardMBean extends Object implements DynamicMBean, MBeanRegistration
An MBean whose management interface is determined by reflection on a Java interface.
This class brings more flexibility to the notion of Management Interface in the use of Standard MBeans. Straightforward use of the patterns for Standard MBeans described in the JMX Specification means that there is a fixed relationship between the implementation class of an MBean and its management interface (i.e., if the implementation class is Thing, the management interface must be ThingMBean). This class makes it possible to keep the convenience of specifying the management interface with a Java interface, without requiring that there be any naming relationship between the implementation and interface classes.
By making a DynamicMBean out of an MBean, this class makes it possible to select any interface implemented by the MBean as its management interface, provided that it complies with JMX patterns (i.e., attributes defined by getter/setter etc...).
This class also provides hooks that make it possible to supply custom descriptions and names for the MBeanInfo returned by the DynamicMBean interface.
Using this class, an MBean can be created with any implementation class name Impl and with a management interface defined (as for current Standard MBeans) by any interface Intf, in one of two general ways:
StandardMBean(impl,interface):
MBeanServer mbs;
...
Impl impl = new Impl(...);
StandardMBean mbean = new StandardMBean(impl, Intf.class, false);
mbs.registerMBean(mbean, objectName);
public class Impl extends StandardMBean implements Intf {
public Impl() {
super(Intf.class, false);
}
// implement methods of Intf
}
[...]
MBeanServer mbs;
....
Impl impl = new Impl();
mbs.registerMBean(impl, objectName);
In either case, the class Impl must implement the interface Intf.
Standard MBeans based on the naming relationship between implementation and interface classes are of course still available.
This class may also be used to construct MXBeans. The usage is exactly the same as for Standard MBeans except that in the examples above, the false parameter to the constructor or super(...) invocation is instead true.
| Modifier | Constructor | Description |
|---|---|---|
protected |
Make a DynamicMBean out of this, using the specified mbeanInterface class. |
|
protected |
Make a DynamicMBean out of this, using the specified mbeanInterface class, and choosing whether the resulting MBean is an MXBean. |
|
| Make a DynamicMBean out of the object implementation, using the specified mbeanInterface class. |
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| Make a DynamicMBean out of the object implementation, using the specified mbeanInterface class, and choosing whether the resultant MBean is an MXBean. |
| Modifier and Type | Method | Description |
|---|---|---|
protected void |
cacheMBeanInfo |
Customization hook: cache the MBeanInfo built for this object. |
Object |
getAttribute |
Obtain the value of a specific attribute of the Dynamic MBean. |
AttributeList |
getAttributes |
Get the values of several attributes of the Dynamic MBean. |
protected MBeanInfo |
getCachedMBeanInfo() |
Customization hook: Return the MBeanInfo cached for this object. |
protected String |
getClassName |
Customization hook: Get the className that will be used in the MBeanInfo returned by this MBean. |
protected MBeanConstructorInfo[] |
getConstructors |
Customization hook: Get the MBeanConstructorInfo[] that will be used in the MBeanInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used in the MBeanAttributeInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used in the MBeanConstructorInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used for the sequence MBeanParameterInfo of the MBeanConstructorInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used in the MBeanFeatureInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used in the MBeanInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used in the MBeanOperationInfo returned by this MBean. |
protected String |
getDescription |
Customization hook: Get the description that will be used for the sequence MBeanParameterInfo of the MBeanOperationInfo returned by this MBean. |
protected int |
getImpact |
Customization hook: Get the impact flag of the operation that will be used in the MBeanOperationInfo returned by this MBean. |
Object |
getImplementation() |
Get the implementation of this Standard MBean (or MXBean). |
Class |
getImplementationClass() |
Get the class of the implementation of this Standard MBean (or MXBean). |
MBeanInfo |
getMBeanInfo() |
Get the MBeanInfo for this MBean. |
final Class |
getMBeanInterface() |
Get the Management Interface of this Standard MBean (or MXBean). |
protected String |
getParameterName |
Customization hook: Get the name that will be used for the sequence MBeanParameterInfo of the MBeanConstructorInfo returned by this MBean. |
protected String |
getParameterName |
Customization hook: Get the name that will be used for the sequence MBeanParameterInfo of the MBeanOperationInfo returned by this MBean. |
Object |
invoke |
Allows an action to be invoked on the Dynamic MBean. |
void |
postDeregister() |
Allows the MBean to perform any operations needed after having been unregistered in the MBean server. |
void |
postRegister |
Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed. |
void |
preDeregister() |
Allows the MBean to perform any operations it needs before being unregistered by the MBean server. |
ObjectName |
preRegister |
Allows the MBean to perform any operations it needs before being registered in the MBean server. |
void |
setAttribute |
Set the value of a specific attribute of the Dynamic MBean. |
AttributeList |
setAttributes |
Sets the values of several attributes of the Dynamic MBean. |
void |
setImplementation |
Replace the implementation object wrapped in this object. |
public StandardMBean(T implementation, Class<T> mbeanInterface) throws NotCompliantMBeanException
Make a DynamicMBean out of the object implementation, using the specified mbeanInterface class.
T - Allows the compiler to check that implementation does indeed implement the class described by mbeanInterface. The compiler can only check this if mbeanInterface is a class literal such as MyMBean.class.implementation - The implementation of this MBean.mbeanInterface - The Management Interface exported by this MBean's implementation. If null, then this object will use standard JMX design pattern to determine the management interface associated with the given implementation.IllegalArgumentException - if the given implementation is null.NotCompliantMBeanException - if the mbeanInterface does not follow JMX design patterns for Management Interfaces, or if the given implementation does not implement the specified interface.protected StandardMBean(Class<?> mbeanInterface) throws NotCompliantMBeanException
Make a DynamicMBean out of this, using the specified mbeanInterface class.
Calls this(this,mbeanInterface). This constructor is reserved to subclasses.
mbeanInterface - The Management Interface exported by this MBean.NotCompliantMBeanException - if the mbeanInterface does not follow JMX design patterns for Management Interfaces, or if this does not implement the specified interface.public StandardMBean(T implementation, Class<T> mbeanInterface, boolean isMXBean)
Make a DynamicMBean out of the object implementation, using the specified mbeanInterface class, and choosing whether the resultant MBean is an MXBean. This constructor can be used to make either Standard MBeans or MXBeans. Unlike the constructor StandardMBean(Object, Class), it does not throw NotCompliantMBeanException.
T - Allows the compiler to check that implementation does indeed implement the class described by mbeanInterface. The compiler can only check this if mbeanInterface is a class literal such as MyMBean.class.implementation - The implementation of this MBean.mbeanInterface - The Management Interface exported by this MBean's implementation. If null, then this object will use standard JMX design pattern to determine the management interface associated with the given implementation.isMXBean - If true, the mbeanInterface parameter names an MXBean interface and the resultant MBean is an MXBean.IllegalArgumentException - if the given implementation is null, or if the mbeanInterface does not follow JMX design patterns for Management Interfaces, or if the given implementation does not implement the specified interface.protected StandardMBean(Class<?> mbeanInterface, boolean isMXBean)
Make a DynamicMBean out of this, using the specified mbeanInterface class, and choosing whether the resulting MBean is an MXBean. This constructor can be used to make either Standard MBeans or MXBeans. Unlike the constructor StandardMBean(Object, Class), it does not throw NotCompliantMBeanException.
Calls this(this, mbeanInterface, isMXBean). This constructor is reserved to subclasses.
mbeanInterface - The Management Interface exported by this MBean.isMXBean - If true, the mbeanInterface parameter names an MXBean interface and the resultant MBean is an MXBean.IllegalArgumentException - if the mbeanInterface does not follow JMX design patterns for Management Interfaces, or if this does not implement the specified interface.public void setImplementation(Object implementation) throws NotCompliantMBeanException
Replace the implementation object wrapped in this object.
implementation - The new implementation of this Standard MBean (or MXBean). The implementation object must implement the Standard MBean (or MXBean) interface that was supplied when this StandardMBean was constructed.IllegalArgumentException - if the given implementation is null.NotCompliantMBeanException - if the given implementation does not implement the Standard MBean (or MXBean) interface that was supplied at construction.public Object getImplementation()
public final Class<?> getMBeanInterface()
public Class<?> getImplementationClass()
public Object getAttribute(String attribute) throws AttributeNotFoundException, MBeanException, ReflectionException
DynamicMBeangetAttribute in interface DynamicMBean
attribute - The name of the attribute to be retrievedAttributeNotFoundException - if specified attribute does not exist or cannot be retrievedMBeanException - Wraps a java.lang.Exception thrown by the MBean's getter.ReflectionException - Wraps a java.lang.Exception thrown while trying to invoke the getter.public void setAttribute(Attribute attribute) throws AttributeNotFoundException, InvalidAttributeValueException, MBeanException, ReflectionException
DynamicMBeansetAttribute in interface DynamicMBean
attribute - The identification of the attribute to be set and the value it is to be set to.AttributeNotFoundException - if specified attribute does not exist or cannot be retrievedInvalidAttributeValueException - if value specified is not valid for the attributeMBeanException - Wraps a java.lang.Exception thrown by the MBean's setter.ReflectionException - Wraps a java.lang.Exception thrown while trying to invoke the MBean's setter.public AttributeList getAttributes(String[] attributes)
DynamicMBeangetAttributes in interface DynamicMBean
attributes - A list of the attributes to be retrieved.public AttributeList setAttributes(AttributeList attributes)
DynamicMBeansetAttributes in interface DynamicMBean
attributes - A list of attributes: The identification of the attributes to be set and the values they are to be set to.public Object invoke(String actionName, Object[] params, String[] signature) throws MBeanException, ReflectionException
DynamicMBeaninvoke in interface DynamicMBean
actionName - The name of the action to be invoked.params - An array containing the parameters to be set when the action is invoked.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.MBeanException - Wraps a java.lang.Exception thrown by the MBean's invoked method.ReflectionException - Wraps a java.lang.Exception thrown while trying to invoke the methodpublic MBeanInfo getMBeanInfo()
MBeanInfo for this MBean. This method implements DynamicMBean.getMBeanInfo().
This method first calls getCachedMBeanInfo() in order to retrieve the cached MBeanInfo for this MBean, if any. If the MBeanInfo returned by getCachedMBeanInfo() is not null, then it is returned.
Otherwise, this method builds a default MBeanInfo for this MBean, using the Management Interface specified for this MBean.
While building the MBeanInfo, this method calls the customization hooks that make it possible for subclasses to supply their custom descriptions, parameter names, etc...
Finally, it calls cacheMBeanInfo() in order to cache the new MBeanInfo.
getMBeanInfo in interface DynamicMBean
protected String getClassName(MBeanInfo info)
info.getClassName().info - The default MBeanInfo derived by reflection.protected String getDescription(MBeanInfo info)
info.getDescription().info - The default MBeanInfo derived by reflection.protected String getDescription(MBeanFeatureInfo info)
Customization hook: Get the description that will be used in the MBeanFeatureInfo returned by this MBean.
Subclasses may redefine this method in order to supply their custom description. The default implementation returns info.getDescription().
This method is called by getDescription(MBeanAttributeInfo), getDescription(MBeanOperationInfo), getDescription(MBeanConstructorInfo).
info - The default MBeanFeatureInfo derived by reflection.protected String getDescription(MBeanAttributeInfo info)
Subclasses may redefine this method in order to supply their custom description. The default implementation returns getDescription((MBeanFeatureInfo) info).
info - The default MBeanAttributeInfo derived by reflection.protected String getDescription(MBeanConstructorInfo info)
getDescription((MBeanFeatureInfo) info).info - The default MBeanConstructorInfo derived by reflection.protected String getDescription(MBeanConstructorInfo ctor, MBeanParameterInfo param, int sequence)
param.getDescription().ctor - The default MBeanConstructorInfo derived by reflection.param - The default MBeanParameterInfo derived by reflection.sequence - The sequence number of the parameter considered ("0" for the first parameter, "1" for the second parameter, etc...).protected String getParameterName(MBeanConstructorInfo ctor, MBeanParameterInfo param, int sequence)
param.getName().ctor - The default MBeanConstructorInfo derived by reflection.param - The default MBeanParameterInfo derived by reflection.sequence - The sequence number of the parameter considered ("0" for the first parameter, "1" for the second parameter, etc...).protected String getDescription(MBeanOperationInfo info)
getDescription((MBeanFeatureInfo) info).info - The default MBeanOperationInfo derived by reflection.protected int getImpact(MBeanOperationInfo info)
info.getImpact().info - The default MBeanOperationInfo derived by reflection.protected String getParameterName(MBeanOperationInfo op, MBeanParameterInfo param, int sequence)
param.getName().op - The default MBeanOperationInfo derived by reflection.param - The default MBeanParameterInfo derived by reflection.sequence - The sequence number of the parameter considered ("0" for the first parameter, "1" for the second parameter, etc...).protected String getDescription(MBeanOperationInfo op, MBeanParameterInfo param, int sequence)
param.getDescription().op - The default MBeanOperationInfo derived by reflection.param - The default MBeanParameterInfo derived by reflection.sequence - The sequence number of the parameter considered ("0" for the first parameter, "1" for the second parameter, etc...).protected MBeanConstructorInfo[] getConstructors(MBeanConstructorInfo[] ctors, Object impl)
null if the wrapped implementation is not this. Indeed, if the wrapped implementation is not this object itself, it will not be possible to recreate a wrapped implementation by calling the implementation constructors through MBeanServer.createMBean(...).ctors - The default MBeanConstructorInfo[] derived by reflection.impl - The wrapped implementation. If null is passed, the wrapped implementation is ignored and ctors is returned.protected MBeanInfo getCachedMBeanInfo()
Subclasses may redefine this method in order to implement their own caching policy. The default implementation stores one MBeanInfo object per instance.
protected void cacheMBeanInfo(MBeanInfo info)
Subclasses may redefine this method in order to implement their own caching policy. The default implementation stores info in this instance. A subclass can define other policies, such as not saving info (so it is reconstructed every time getMBeanInfo() is called) or sharing a unique MBeanInfo object when several StandardMBean instances have equal MBeanInfo values.
info - the new MBeanInfo to cache. Any previously cached value is discarded. This parameter may be null, in which case there is no new cached value.public ObjectName preRegister(MBeanServer server, ObjectName name) throws Exception
Allows the MBean to perform any operations it needs before being registered in the MBean server. If the name of the MBean is not specified, the MBean can provide a name for its registration. If any exception is raised, the MBean will not be registered in the MBean server.
The default implementation of this method returns the name parameter. It does nothing else for Standard MBeans. For MXBeans, it records the MBeanServer and ObjectName parameters so they can be used to translate inter-MXBean references.
It is good practice for a subclass that overrides this method to call the overridden method via super.preRegister(...). This is necessary if this object is an MXBean that is referenced by attributes or operations in other MXBeans.
preRegister in interface MBeanRegistration
server - The MBean server in which the MBean will be registered.name - The object name of the MBean. This name is null if the name parameter to one of the createMBean or registerMBean methods in the MBeanServer interface is null. In that case, this method must return a non-null ObjectName for the new MBean.name parameter is not null, it will usually but not necessarily be the returned value.IllegalArgumentException - if this is an MXBean and name is null.InstanceAlreadyExistsException - if this is an MXBean and it has already been registered under another name (in this MBean Server or another).Exception - no other checked exceptions are thrown by this method but Exception is declared so that subclasses can override the method and throw their own exceptions.public void postRegister(Boolean registrationDone)
Allows the MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.
The default implementation of this method does nothing for Standard MBeans. For MXBeans, it undoes any work done by preRegister if registration fails.
It is good practice for a subclass that overrides this method to call the overridden method via super.postRegister(...). This is necessary if this object is an MXBean that is referenced by attributes or operations in other MXBeans.
postRegister in interface MBeanRegistration
registrationDone - Indicates whether or not the MBean has been successfully registered in the MBean server. The value false means that the registration phase has failed.public void preDeregister() throws Exception
Allows the MBean to perform any operations it needs before being unregistered by the MBean server.
The default implementation of this method does nothing.
It is good practice for a subclass that overrides this method to call the overridden method via super.preDeregister(...).
preDeregister in interface MBeanRegistration
Exception - no checked exceptions are throw by this method but Exception is declared so that subclasses can override this method and throw their own exceptions.public void postDeregister()
Allows the MBean to perform any operations needed after having been unregistered in the MBean server.
The default implementation of this method does nothing for Standard MBeans. For MXBeans, it removes any information that was recorded by the preRegister method.
It is good practice for a subclass that overrides this method to call the overridden method via super.postRegister(...). This is necessary if this object is an MXBean that is referenced by attributes or operations in other MXBeans.
postDeregister in interface MBeanRegistration
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https://docs.oracle.com/en/java/javase/21/docs/api/java.management/javax/management/StandardMBean.html