ModelMBeanInfo (Java SE 25 & JDK 25)
Description: declaration: module: java.management, package: javax.management.modelmbean, interface: ModelMBeanInfo
Keywords: javax.management.modelmbean.ModelMBeanInfo interface

# Interface ModelMBeanInfo

All Known Implementing Classes:
  `ModelMBeanInfoSupport`

public interface ModelMBeanInfo
This interface is implemented by the ModelMBeanInfo for every ModelMBean. An implementation of this interface must be shipped with every JMX Agent.

Java resources wishing to be manageable instantiate the ModelMBean using the MBeanServer's createMBean method. The resource then sets the ModelMBeanInfo and Descriptors for the ModelMBean instance. The attributes, operations, and notifications exposed via the ModelMBeanInfo for the ModelMBean comprise the management interface and are accessible from MBeans, connectors/adaptors like other MBeans. Through the Descriptors, values and methods in the managed application can be defined and mapped to attributes and operations of the ModelMBean. This mapping can be defined during development in a file or dynamically and programmatically at runtime.

Every ModelMBean which is instantiated in the MBeanServer becomes manageable: its attributes, operations, and notifications become remotely accessible through the connectors/adaptors connected to that MBeanServer. A Java object cannot be registered in the MBeanServer unless it is a JMX compliant MBean. By instantiating a ModelMBean, resources are guaranteed that the MBean is valid. MBeanException and RuntimeOperationsException must be thrown on every public method. This allows for wrapping exceptions from distributed communications (RMI, EJB, etc.)

Since:
  1.5

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Object`
  `clone()`
  Creates and returns a copy of this object.
  `ModelMBeanAttributeInfo`
  `getAttribute(String inName)`
  Returns a ModelMBeanAttributeInfo requested by name.
  `MBeanAttributeInfo[]`
  `getAttributes()`
  Returns the list of attributes exposed for management.
  `String`
  `getClassName()`
  Returns the name of the Java class of the MBean described by this `MBeanInfo`.
  `MBeanConstructorInfo[]`
  `getConstructors()`
  Returns the list of the public constructors of the MBean.
  `String`
  `getDescription()`
  Returns a human readable description of the MBean.
  `Descriptor`
  `getDescriptor(String inDescriptorName, String inDescriptorType)`
  Returns a Descriptor requested by name and descriptorType.
  `Descriptor[]`
  `getDescriptors(String inDescriptorType)`
  Returns a Descriptor array consisting of all Descriptors for the ModelMBeanInfo of type inDescriptorType.
  `Descriptor`
  `getMBeanDescriptor()`
  Returns the ModelMBean's descriptor which contains MBean wide policies.
  `ModelMBeanNotificationInfo`
  `getNotification(String inName)`
  Returns a ModelMBeanNotificationInfo requested by name.
  `MBeanNotificationInfo[]`
  `getNotifications()`
  Returns the list of the notifications emitted by the MBean.
  `ModelMBeanOperationInfo`
  `getOperation(String inName)`
  Returns a ModelMBeanOperationInfo requested by name.
  `MBeanOperationInfo[]`
  `getOperations()`
  Returns the list of operations of the MBean.
  `void`
  `setDescriptor(Descriptor inDescriptor, String inDescriptorType)`
  Sets descriptors in the info array of type inDescriptorType for the ModelMBean.
  `void`
  `setDescriptors(Descriptor[] inDescriptors)`
  Adds or replaces descriptors in the ModelMBeanInfo.
  `void`
  `setMBeanDescriptor(Descriptor inDescriptor)`
  Sets the ModelMBean's descriptor.

- ## Method Details

  - ### getDescriptors

    Descriptor[] getDescriptors(String inDescriptorType) throws MBeanException, RuntimeOperationsException
    Returns a Descriptor array consisting of all Descriptors for the ModelMBeanInfo of type inDescriptorType.
    Parameters:
      `inDescriptorType` - value of descriptorType field that must be set for the descriptor to be returned. Must be "mbean", "attribute", "operation", "constructor" or "notification". If it is null or empty then all types will be returned.
    Returns:
      Descriptor array containing all descriptors for the ModelMBean if type inDescriptorType.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - Wraps an IllegalArgumentException when the descriptorType in parameter is not one of: "mbean", "attribute", "operation", "constructor", "notification", empty or null.
    See Also:
      - `setDescriptors(Descriptor[])`

  - ### setDescriptors

    void setDescriptors(Descriptor[] inDescriptors) throws MBeanException, RuntimeOperationsException
    Adds or replaces descriptors in the ModelMBeanInfo.
    Parameters:
      `inDescriptors` - The descriptors to be set in the ModelMBeanInfo. Null elements of the list will be ignored. All descriptors must have name and descriptorType fields.
    Throws:
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for a null or invalid descriptor.
      `MBeanException` - Wraps a distributed communication Exception.
    See Also:
      - `getDescriptors(String)`

  - ### getDescriptor

    Descriptor getDescriptor(String inDescriptorName, String inDescriptorType) throws MBeanException, RuntimeOperationsException
    Returns a Descriptor requested by name and descriptorType.
    Parameters:
      `inDescriptorName` - The name of the descriptor.
      `inDescriptorType` - The type of the descriptor being requested. If this is null or empty then all types are searched. Valid types are 'mbean', 'attribute', 'constructor' 'operation', and 'notification'. This value will be equal to the 'descriptorType' field in the descriptor that is returned.
    Returns:
      Descriptor containing the descriptor for the ModelMBean with the same name and descriptorType. If no descriptor is found, null is returned.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for a null descriptor name or null or invalid type. The type must be "mbean","attribute", "constructor", "operation", or "notification".
    See Also:
      - `setDescriptor(Descriptor, String)`

  - ### setDescriptor

    void setDescriptor(Descriptor inDescriptor, String inDescriptorType) throws MBeanException, RuntimeOperationsException
    Sets descriptors in the info array of type inDescriptorType for the ModelMBean. The setDescriptor method of the corresponding ModelMBean*Info will be called to set the specified descriptor.
    Parameters:
      `inDescriptor` - The descriptor to be set in the ModelMBean. It must NOT be null. All descriptors must have name and descriptorType fields.
      `inDescriptorType` - The type of the descriptor being set. If this is null then the descriptorType field in the descriptor is used. If specified this value must be set in the descriptorType field in the descriptor. Must be "mbean","attribute", "constructor", "operation", or "notification".
    Throws:
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for illegal or null arguments or if the name field of the descriptor is not found in the corresponding MBeanAttributeInfo or MBeanConstructorInfo or MBeanNotificationInfo or MBeanOperationInfo.
      `MBeanException` - Wraps a distributed communication Exception.
    See Also:
      - `getDescriptor(String, String)`

  - ### getMBeanDescriptor

    Descriptor getMBeanDescriptor() throws MBeanException, RuntimeOperationsException

    Returns the ModelMBean's descriptor which contains MBean wide policies. This descriptor contains metadata about the MBean and default policies for persistence and caching.

    The fields in the descriptor are defined, but not limited to, the following. Note that when the Type in this table is Number, a String that is the decimal representation of a Long can also be used.

    ModelMBean Fields
    Name | Type | Meaning
    --- | --- | ---
    name | String | MBean name.
    descriptorType | String | Must be "mbean".
    displayName | String | Name of MBean to be used in displays.
    persistPolicy | String | One of: OnUpdate|OnTimer|NoMoreOftenThan|OnUnregister|Always|Never. See the section "MBean Descriptor Fields" in the JMX specification document.
    persistLocation | String | The fully qualified directory name where the MBean should be persisted (if appropriate).
    persistFile | String | File name into which the MBean should be persisted.
    persistPeriod | Number | Frequency of persist cycle in seconds, for OnTime and NoMoreOftenThan PersistPolicy
    currencyTimeLimit | Number | How long cached value is valid: <0 never, =0 always, >0 seconds.
    log | String | t: log all notifications, f: log no notifications.
    logfile | String | Fully qualified filename to log events to.
    visibility | Number | 1-4 where 1: always visible 4: rarely visible.
    export | String | Name to be used to export/expose this MBean so that it is findable by other JMX Agents.
    presentationString | String | XML formatted string to allow presentation of data to be associated with the MBean.

    The default descriptor is: name=className,descriptorType="mbean", displayName=className, persistPolicy="never",log="F",visibility="1" If the descriptor does not contain all these fields, they will be added with these default values.

    Note: because of inconsistencies in previous versions of this specification, it is recommended not to use negative or zero values for `currencyTimeLimit`. To indicate that a cached value is never valid, omit the `currencyTimeLimit` field. To indicate that it is always valid, use a very large number for this field.

    Returns:
      the MBean descriptor.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - a `RuntimeException` occurred while getting the descriptor.
    See Also:
      - `setMBeanDescriptor(Descriptor)`

  - ### setMBeanDescriptor

    void setMBeanDescriptor(Descriptor inDescriptor) throws MBeanException, RuntimeOperationsException
    Sets the ModelMBean's descriptor. This descriptor contains default, MBean wide metadata about the MBean and default policies for persistence and caching. This operation does a complete replacement of the descriptor, no merging is done. If the descriptor to set to is null then the default descriptor will be created. The default descriptor is: name=className,descriptorType="mbean", displayName=className, persistPolicy="never",log="F",visibility="1" If the descriptor does not contain all these fields, they will be added with these default values. See `getMBeanDescriptor` method javadoc for description of valid field names.
    Parameters:
      `inDescriptor` - the descriptor to set.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for invalid descriptor.
    See Also:
      - `getMBeanDescriptor()`

  - ### getAttribute

    ModelMBeanAttributeInfo getAttribute(String inName) throws MBeanException, RuntimeOperationsException
    Returns a ModelMBeanAttributeInfo requested by name.
    Parameters:
      `inName` - The name of the ModelMBeanAttributeInfo to get. If no ModelMBeanAttributeInfo exists for this name null is returned.
    Returns:
      the attribute info for the named attribute, or null if there is none.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for a null attribute name.

  - ### getOperation

    ModelMBeanOperationInfo getOperation(String inName) throws MBeanException, RuntimeOperationsException
    Returns a ModelMBeanOperationInfo requested by name.
    Parameters:
      `inName` - The name of the ModelMBeanOperationInfo to get. If no ModelMBeanOperationInfo exists for this name null is returned.
    Returns:
      the operation info for the named operation, or null if there is none.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for a null operation name.

  - ### getNotification

    ModelMBeanNotificationInfo getNotification(String inName) throws MBeanException, RuntimeOperationsException
    Returns a ModelMBeanNotificationInfo requested by name.
    Parameters:
      `inName` - The name of the ModelMBeanNotificationInfo to get. If no ModelMBeanNotificationInfo exists for this name null is returned.
    Returns:
      the info for the named notification, or null if there is none.
    Throws:
      `MBeanException` - Wraps a distributed communication Exception.
      `RuntimeOperationsException` - Wraps an IllegalArgumentException for a null notification name.

  - ### clone

    Object clone()
    Creates and returns a copy of this object.
    Returns:
      a copy of this object

  - ### getAttributes

    MBeanAttributeInfo[] getAttributes()
    Returns the list of attributes exposed for management. Each attribute is described by an `MBeanAttributeInfo` object.
    Returns:
      An array of `MBeanAttributeInfo` objects.

  - ### getClassName

    String getClassName()
    Returns the name of the Java class of the MBean described by this `MBeanInfo`.
    Returns:
      the Java class name.

  - ### getConstructors

    MBeanConstructorInfo[] getConstructors()
    Returns the list of the public constructors of the MBean. Each constructor is described by an `MBeanConstructorInfo` object.
    Returns:
      An array of `MBeanConstructorInfo` objects.

  - ### getDescription

    String getDescription()
    Returns a human readable description of the MBean.
    Returns:
      the description.

  - ### getNotifications

    MBeanNotificationInfo[] getNotifications()
    Returns the list of the notifications emitted by the MBean. Each notification is described by an `MBeanNotificationInfo` object.

    In addition to any notification specified by the application, a ModelMBean may always send also two additional notifications:

    - One with descriptor name "GENERIC" and displayName "jmx.modelmbean.generic"
    - Second is a standard attribute change notification with descriptor name "ATTRIBUTE_CHANGE" and displayName "jmx.attribute.change"
    Thus any implementation of ModelMBeanInfo should always add those two notifications in addition to those specified by the application.
    Returns:
      An array of `MBeanNotificationInfo` objects.

  - ### getOperations

    MBeanOperationInfo[] getOperations()
    Returns the list of operations of the MBean. Each operation is described by an `MBeanOperationInfo` object.
    Returns:
      An array of `MBeanOperationInfo` objects.