API java : Descriptor

javax.management
Interface Descriptor

All Superinterfaces:

Cloneable, Serializable

All Known Implementing Classes:

DescriptorSupport

public interface Descriptor
extends Serializable, Cloneable

This interface represents the behavioral metadata set for a JMX Element. For examples, a descriptor is part of the ModelMBeanInfo, ModelMBeanNotificationInfo, ModelMBeanAttributeInfo, ModelMBeanConstructorInfo, and ModelMBeanParameterInfo.

A descriptor consists of a collection of fields. Each field is in fieldname=fieldvalue format.

All field names and values are not predefined. New fields can be defined and added by any program. In the case of ModelMBean some fields have been predefined for consistency of implementation and support by the ModelMBeanInfo ModelMBean*Info, and ModelMBean classes.

Since:

1.5

Method Summary
Object	clone()           Returns a new Descriptor which is a duplicate of the Descriptor.
String[]	getFieldNames()           Returns all the fields names in the descriptor.
String[]	getFields()           Returns all of the fields contained in this descriptor as a string array.
Object	getFieldValue(String fieldName)           Returns the value for a specific fieldname.
Object[]	getFieldValues(String[] fieldNames)           Returns all the field values in the descriptor as an array of Objects.
boolean	isValid()           Returns true if all of the fields have legal values given their names.
void	removeField(String fieldName)           Removes a field from the descriptor.
void	setField(String fieldName, Object fieldValue)           Sets the value for a specific fieldname.
void	setFields(String[] fieldNames, Object[] fieldValues)           Sets all Fields in the list to the new value in with the same index in the fieldValue array.

 

Method Detail

getFieldValue

Object getFieldValue(String fieldName)
                     throws RuntimeOperationsException

Returns the value for a specific fieldname.

Parameters:

fieldName - The field name in question; if not found, null is returned.

Returns:

Object Field value.

Throws:

RuntimeOperationsException - for illegal value for field name.

setField

void setField(String fieldName,
              Object fieldValue)
              throws RuntimeOperationsException

Sets the value for a specific fieldname. The field value will be validated before it is set. If it is not valid, then an exception will be thrown. This will modify an existing field or add a new field.

Parameters:

fieldName - The field name to be set. Cannot be null or empty.

fieldValue - The field value to be set for the field name. Can be null.

Throws:

RuntimeOperationsException - for illegal value for field name or field value.

getFields

String[] getFields()

Returns all of the fields contained in this descriptor as a string array.

Returns:

String array of fields in the format fieldName=fieldValue If the value of a field is not a String, then the toString() method will be called on it and the returned value used as the value for the field in the returned array. Object values which are not Strings will be enclosed in parentheses. If the descriptor is empty, you will get an empty array.

See Also:

setFields(java.lang.String[], java.lang.Object[])

getFieldNames

String[] getFieldNames()

Returns all the fields names in the descriptor.

Returns:

String array of fields names. If the descriptor is empty, you will get an empty array.

getFieldValues

Object[] getFieldValues(String[] fieldNames)

Returns all the field values in the descriptor as an array of Objects. The returned values are in the same order as the fieldNames String array parameter.

Parameters:

fieldNames - String array of the names of the fields that the values should be returned for. If the array is empty then an empty array will be returned. If the array is 'null' then all values will be returned. If a field name in the array does not exist, then null is returned for the matching array element being returned.

Returns:

Object array of field values. If the descriptor is empty, you will get an empty array.

removeField

void removeField(String fieldName)

Removes a field from the descriptor.

Parameters:

fieldName - String name of the field to be removed. If the field is not found no exception is thrown.

setFields

void setFields(String[] fieldNames,
               Object[] fieldValues)
               throws RuntimeOperationsException

Sets all Fields in the list to the new value in with the same index in the fieldValue array. Array sizes must match. The field value will be validated before it is set. If it is not valid, then an exception will be thrown. If the arrays are empty, then no change will take effect.

Parameters:

fieldNames - String array of field names. The array and array elements cannot be null.

fieldValues - Object array of the corresponding field values. The array cannot be null. Elements of the array can be null.

Throws:

RuntimeOperationsException - for illegal value for field Names or field Values. Neither can be null. The array lengths must be equal. If the descriptor construction fails for any reason, this exception will be thrown.

See Also:

getFields()

clone

Object clone()
             throws RuntimeOperationsException

Returns a new Descriptor which is a duplicate of the Descriptor.

Throws:

RuntimeOperationsException - for illegal value for field Names or field Values. If the descriptor construction fails for any reason, this exception will be thrown.

isValid

boolean isValid()
                throws RuntimeOperationsException

Returns true if all of the fields have legal values given their names.

Returns:

true if the values are legal.

Throws:

RuntimeOperationsException - If the validity checking fails for any reason, this exception will be thrown.