javax.management

Class StandardMBean

public class StandardMBean extends Object implements DynamicMBean

Provides a dynamic management bean by using reflection on an interface and an implementing class. By default, a bean instance is paired up with its interface based on specific naming conventions (if the implementation is called X, the interface must be XMBean). Using this class removes the need to use a specific naming system to match up the two. Instead, an instance of this bean is created either via explicit construction or subclassing, and this provides access to the attributes, constructors and operations of the implementation via reflection. Various hooks are provided in order to allow customization of this process.

Since: 1.5

Constructor Summary
protected	StandardMBean(Class<?> iface) Constructs a new {@link StandardMBean} using the specified interface and `this` as the instance.
<T>	StandardMBean(T impl, Class<T> iface) Constructs a new {@link StandardMBean} using the specified interface and the supplied instance as the implementation.

Method Summary
protected void	cacheMBeanInfo(MBeanInfo info) Caches the {@link MBeanInfo} instance for this object.
Object	getAttribute(String name) Obtains the value of the specified attribute of the management bean.
AttributeList	getAttributes(String[] names) Obtains the values of each of the specified attributes of the management bean.
protected MBeanInfo	getCachedMBeanInfo() Returns the cached {@link MBeanInfo} instance for this object.
protected String	getClassName(MBeanInfo info) Returns the class name that will be used in the {@link MBeanInfo} instance.
protected MBeanConstructorInfo[]	getConstructors(MBeanConstructorInfo[] constructors, Object impl) Returns information on the constructors that will be used in the {@link MBeanInfo} instance.
protected String	getDescription(MBeanAttributeInfo info) Returns the description of the attribute that will be used in the supplied {@link MBeanAttributeInfo} instance.
protected String	getDescription(MBeanConstructorInfo info) Returns the description of the constructor that will be used in the supplied {@link MBeanConstructorInfo} instance.
protected String	getDescription(MBeanConstructorInfo info, MBeanParameterInfo param, int n) Returns the description of the nth parameter of the constructor that will be used in the supplied {@link MBeanParameterInfo} instance.
protected String	getDescription(MBeanFeatureInfo info) Returns the description of the supplied feature that will be used in the supplied {@link MBeanFeatureInfo} instance.
protected String	getDescription(MBeanInfo info) Returns the description of the bean that will be used in the supplied {@link MBeanInfo} instance.
protected String	getDescription(MBeanOperationInfo info) Returns the description of the operation that will be used in the supplied {@link MBeanOperationInfo} instance.
protected String	getDescription(MBeanOperationInfo info, MBeanParameterInfo param, int n) Returns the description of the nth parameter of the operation that will be used in the supplied {@link MBeanParameterInfo} instance.
protected int	getImpact(MBeanOperationInfo info) Returns the impact of the operation that will be used in the supplied {@link MBeanOperationInfo} instance.
Object	getImplementation() Returns the instance that implements this bean.
Class<?>	getImplementationClass() Returns the class of the instance that implements this bean.
MBeanInfo	getMBeanInfo() Returns an information object which lists the attributes and actions associated with the management bean.
Class<?>	getMBeanInterface() Returns the interface for this management bean.
protected String	getParameterName(MBeanConstructorInfo info, MBeanParameterInfo param, int n) Returns the name of the nth parameter of the constructor that will be used in the supplied {@link MBeanParameterInfo} instance.
protected String	getParameterName(MBeanOperationInfo info, MBeanParameterInfo param, int n) Returns the name of the nth parameter of the operation that will be used in the supplied {@link MBeanParameterInfo} instance.
Object	invoke(String name, Object[] params, String[] signature) Invokes the specified action on the management bean using the supplied parameters.
void	setAttribute(Attribute attribute) Sets the value of the specified attribute of the management bean.
AttributeList	setAttributes(AttributeList attributes) Sets the value of each of the specified attributes to that supplied by the {@link Attribute} object.
void	setImplementation(Object impl) Replaces the implementation of the interface used by this instance with the one specified.

Constructor Detail

StandardMBean

protected StandardMBean(Class<?> iface)

Constructs a new {@link StandardMBean} using the specified interface and this as the instance. This should be used to create an instance via subclassing.

Parameters: iface the interface this bean implements, or null if the interface should be determined using the naming convention (class X has interface XMBean).

Throws: NotCompliantMBeanException if this class doesn't implement the interface or a method appears in the interface that doesn't comply with the naming conventions.

StandardMBean

public <T> StandardMBean(T impl, Class<T> iface)

Constructs a new {@link StandardMBean} using the specified interface and the supplied instance as the implementation.

Parameters: impl the implementation. iface the interface the bean implements, or null if the interface should be determined using the naming convention (class X has interface XMBean).

Throws: IllegalArgumentException if impl is null. NotCompliantMBeanException if impl doesn't implement the interface or a method appears in the interface that doesn't comply with the naming conventions.

Method Detail

cacheMBeanInfo

protected void cacheMBeanInfo(MBeanInfo info)

Caches the {@link MBeanInfo} instance for this object. This is a customization hook, so that subclasses can choose the caching policy used. The default implementation caches the value in the instance itself. Subclasses may override this so as to not cache the data at all, or so as to use a cache shared between multiple beans.

Parameters: info the {@link MBeanInfo} instance to cache, or null if there is no new value to cache. When the value is not null, the cache should replace the current value with the value supplied here.

getAttribute

public Object getAttribute(String name)

Obtains the value of the specified attribute of the management bean. The management bean should perform a lookup for the named attribute, and return its value by calling the appropriate getter method, if possible.

Parameters: name the name of the attribute to retrieve.

Returns: the value of the specified attribute.

Throws: AttributeNotFoundException if the name does not correspond to an attribute of the bean. MBeanException if retrieving the attribute causes the bean to throw an exception (which becomes the cause of this exception). ReflectionException if an exception occurred in trying to use the reflection interface to lookup the attribute. The thrown exception is the cause of this exception.

getAttributes

public AttributeList getAttributes(String[] names)

Obtains the values of each of the specified attributes of the management bean. The returned list includes those attributes that were retrieved and their corresponding values.

Parameters: names the names of the attributes to retrieve.

Returns: a list of the retrieved attributes.

getCachedMBeanInfo

protected MBeanInfo getCachedMBeanInfo()

Returns the cached {@link MBeanInfo} instance for this object. This is a customization hook, so that subclasses can choose the caching policy used. The default implementation caches the value in the instance itself, and returns this value on calls to this method.

Returns: the cached {@link MBeanInfo} instance, or null if no value is cached.

getClassName

protected String getClassName(MBeanInfo info)

Returns the class name that will be used in the {@link MBeanInfo} instance. This is a customization hook, so that subclasses can provide a custom class name. By default, this returns the class name from the supplied {@link MBeanInfo} instance.

Parameters: info the {@link MBeanInfo} instance constructed via reflection.

Returns: the class name to use in the instance.

getConstructors

protected MBeanConstructorInfo[] getConstructors(MBeanConstructorInfo[] constructors, Object impl)

Returns information on the constructors that will be used in the {@link MBeanInfo} instance. This is a customization hook, so that subclasses can provide their own information on the bean's constructors, if necessary. By default, this method returns null unless the implementation supplied is either null or this. This default implementation prevents the use of {@link MBeanServer#createMBean} in cases where the bean is not created as a subclass of {@link StandardMBean}.

Parameters: constructors the constructor information created via reflection. impl the implementation, or null if this should be ignored.

Returns: the constructor information to use.

getDescription

protected String getDescription(MBeanAttributeInfo info)

Returns the description of the attribute that will be used in the supplied {@link MBeanAttributeInfo} instance. This is a customization hook, so that subclasses can provide a custom description. By default, this calls {@link #getDescription(MBeanFeatureInfo)} with the supplied {@link MBeanAttributeInfo} instance.

Parameters: info the {@link MBeanAttributeInfo} instance constructed via reflection.