javax.management

Class MBeanInfo

public class MBeanInfo extends Object implements Cloneable, Serializable

Describes the interface of a management bean. This allows the user to access the bean dynamically, without knowing the details of any of its attributes, operations, constructors or notifications beforehand. The information is immutable as standard. Of course, subclasses may change this, but this behaviour is not recommended.

The contents of this class, for standard management beans, are dynamically compiled using reflection. {@link #getClassName()} and {@link #getConstructors()} return the name of the class and its constructors, respectively. This is much the same as could be obtained by reflection on the bean. {@link #getAttributes()} and {@link #getOperations()}, however, do something more in splitting the methods of the class into two sets. Those of the form, getXXX, setXXX and isXXX are taken to be the accessors and mutators of a series of attributes, with XXX being the attribute name. These are returned by {@link getAttributes()} and the {@link Attribute} class can be used to manipulate them. The remaining methods are classified as operations and returned by {@link getOperations()}.

Beans can also broadcast notifications. If the bean provides this facility, by implementing the {@link NotificationBroadcaster} interface, then an array of {@link MBeanNotificationInfo} objects may be obtained from {@link #getNotifications()}, which describe the notifications emitted.

Model management beans and open management beans also supply an instance of this class, as part of implementing the {@link DynamicMBean#getMBeanInfo()} method of {@link DynamicMBean}.

Since: 1.5

Constructor Summary
MBeanInfo(String name, String desc, MBeanAttributeInfo[] attribs, MBeanConstructorInfo[] cons, MBeanOperationInfo[] ops, MBeanNotificationInfo[] notifs)
Constructs a new {@link MBeanInfo} using the supplied class name and description with the given attributes, operations, constructors and notifications.
Method Summary
Objectclone()
Returns a shallow clone of the information.
booleanequals(Object obj)
Compares this feature with the supplied object.
MBeanAttributeInfo[]getAttributes()
Returns descriptions of each of the attributes provided by this management bean.
StringgetClassName()
Returns the class name of the management bean.
MBeanConstructorInfo[]getConstructors()
Returns descriptions of each of the constructors provided by this management bean.
StringgetDescription()
Returns a description of the management bean.
MBeanNotificationInfo[]getNotifications()
Returns descriptions of each of the notifications emitted by this management bean.
MBeanOperationInfo[]getOperations()
Returns descriptions of each of the operations provided by this management bean.
inthashCode()
Returns the hashcode of the information as the sum of the hashcode of the classname, description and each array.
StringtoString()

Returns a textual representation of this instance.

Constructor Detail

MBeanInfo

public MBeanInfo(String name, String desc, MBeanAttributeInfo[] attribs, MBeanConstructorInfo[] cons, MBeanOperationInfo[] ops, MBeanNotificationInfo[] notifs)
Constructs a new {@link MBeanInfo} using the supplied class name and description with the given attributes, operations, constructors and notifications. The class name does not have to actually specify a valid class that can be loaded by the MBean server or class loader; it merely has to be a syntactically correct class name. Any of the arrays may be null; this will be treated as if an empty array was supplied. A copy of the arrays is taken, so later changes have no effect.

Parameters: name the name of the class this instance describes. desc a description of the bean. attribs the attribute descriptions for the bean, or null. cons the constructor descriptions for the bean, or null. ops the operation descriptions for the bean, or null. notifs the notification descriptions for the bean, or null.

Method Detail

clone

public Object clone()
Returns a shallow clone of the information. This is simply a new copy of each string and a clone of each array, which still references the same objects, as obtained by the {@link Object} implementation of {@link Object#clone()}. As the fields can not be changed, this method is only really of interest to subclasses which may add new mutable fields or make the existing ones mutable.

Returns: a shallow clone of this {@link MBeanInfo}.

equals

public boolean equals(Object obj)
Compares this feature with the supplied object. This returns true iff the object is an instance of {@link MBeanInfo} and {@link Object#equals()} returns true for a comparison of the class name and description, and the arrays each contain the same elements in the same order (but one may be longer than the other).

Parameters: obj the object to compare.

Returns: true if the object is a {@link MBeanInfo} instance, className.equals(object.getClassName()), description.equals(object.getDescription()) and the corresponding elements of the arrays are equal.

getAttributes

public MBeanAttributeInfo[] getAttributes()
Returns descriptions of each of the attributes provided by this management bean. The returned value is a shallow copy of the attribute array maintained by this instance. Hence, changing the elements of the returned array will not affect the attribute array, and the elements (instances of the {@link MBeanAttributeInfo} class) are immutable.

Returns: an array of {@link MBeanAttributeInfo} objects, representing the attributes emitted by this management bean.

getClassName

public String getClassName()
Returns the class name of the management bean.

Returns: the bean's class name.

getConstructors

public MBeanConstructorInfo[] getConstructors()
Returns descriptions of each of the constructors provided by this management bean. The returned value is a shallow copy of the constructor array maintained by this instance. Hence, changing the elements of the returned array will not affect the constructor array, and the elements (instances of the {@link MBeanConstructorInfo} class) are immutable.

Returns: an array of {@link MBeanConstructorInfo} objects, representing the constructors emitted by this management bean.

getDescription

public String getDescription()
Returns a description of the management bean.

Returns: the bean's description.

getNotifications

public MBeanNotificationInfo[] getNotifications()
Returns descriptions of each of the notifications emitted by this management bean. The returned value is a shallow copy of the notification array maintained by this instance. Hence, changing the elements of the returned array will not affect the notification array, and the elements (instances of the {@link MBeanNotificationInfo} class) are immutable.

Returns: an array of {@link MBeanNotificationInfo} objects, representing the notifications emitted by this management bean.

getOperations

public MBeanOperationInfo[] getOperations()
Returns descriptions of each of the operations provided by this management bean. The returned value is a shallow copy of the operation array maintained by this instance. Hence, changing the elements of the returned array will not affect the operation array, and the elements (instances of the {@link MBeanOperationInfo} class) are immutable.

Returns: an array of {@link MBeanOperationInfo} objects, representing the operations emitted by this management bean.

hashCode

public int hashCode()
Returns the hashcode of the information as the sum of the hashcode of the classname, description and each array.

Returns: the hashcode of the information.

toString

public String toString()

Returns a textual representation of this instance. This is constructed using the class name (javax.management.MBeanInfo), the name and description of the bean and the contents of the four arrays.

As instances of this class are immutable, the return value is computed just once for each instance and reused throughout its life.

Returns: a @link{java.lang.String} instance representing the instance in textual form.