| JavaTM 2 Platform Std. Ed. v1.6.0
javax.management.modelmbean
Class DescriptorSupport
java.lang.Object
 javax.management.modelmbean.DescriptorSupport
- All Implemented Interfaces:
- Serializable, Cloneable, Descriptor
public class DescriptorSupport - extends Object
- implements Descriptor
This class represents the metadata set for a ModelMBean element. 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. Field names are not case sensitive,
case will be preserved on field values.
All field names and values are not predefined. New fields can be
defined and added by any program. Some fields have been predefined
for consistency of implementation and support by the
ModelMBeanInfo, ModelMBeanAttributeInfo, ModelMBeanConstructorInfo,
ModelMBeanNotificationInfo, ModelMBeanOperationInfo and ModelMBean
classes.
The serialVersionUID of this class is -6292969195866300415L.
- Since:
- 1.5
- See Also:
- Serialized Form
|
Method Summary |
Object |
clone()
Returns a new Descriptor which is a duplicate of the Descriptor. |
boolean |
equals(Object o)
Compares this descriptor to the given object. |
String[] |
getFieldNames()
Returns all the field 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 field name, or null if no value
is present for that name. |
Object[] |
getFieldValues(String... fieldNames)
Returns all the field values in the descriptor as an array of Objects. |
int |
hashCode()
Returns the hash code value for this descriptor. |
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 field name. |
void |
setFields(String[] fieldNames,
Object[] fieldValues)
Sets all fields in the field names array to the new value with
the same index in the field values array. |
String |
toString()
Returns a human readable string representing the
descriptor. |
String |
toXMLString()
Returns an XML String representing the descriptor. |
DescriptorSupport
public DescriptorSupport()
- Descriptor default constructor.
Default initial descriptor size is 20. It will grow as needed.
Note that the created empty descriptor is not a valid descriptor
(the method isValid returns false)
DescriptorSupport
public DescriptorSupport(int initNumFields)
throws MBeanException,
RuntimeOperationsException
- Descriptor constructor. Takes as parameter the initial
capacity of the Map that stores the descriptor fields.
Capacity will grow as needed.
Note that the created empty
descriptor is not a valid descriptor (the method isValid returns false).
- Parameters:
initNumFields - The initial capacity of the Map that
stores the descriptor fields.
- Throws:
RuntimeOperationsException - for illegal value for
initNumFields (<= 0)
MBeanException - Wraps a distributed communication Exception.
DescriptorSupport
public DescriptorSupport(DescriptorSupport inDescr)
- Descriptor constructor taking a Descriptor as parameter.
Creates a new descriptor initialized to the values of the
descriptor passed in parameter.
- Parameters:
inDescr - the descriptor to be used to initialize the
constructed descriptor. If it is null or contains no descriptor
fields, an empty Descriptor will be created.
DescriptorSupport
public DescriptorSupport(String inStr)
throws MBeanException,
RuntimeOperationsException,
XMLParseException
Descriptor constructor taking an XML String.
The format of the XML string is not defined, but an
implementation must ensure that the string returned by
toXMLString() on an existing
descriptor can be used to instantiate an equivalent
descriptor using this constructor.
In this implementation, all field values will be created
as Strings. If the field values are not Strings, the
programmer will have to reset or convert these fields
correctly.
- Parameters:
inStr - An XML-formatted string used to populate this
Descriptor. The format is not defined, but any
implementation must ensure that the string returned by
method toXMLString on an existing
descriptor can be used to instantiate an equivalent
descriptor when instantiated using this constructor.
- Throws:
RuntimeOperationsException - If the String inStr
passed in parameter is null
XMLParseException - XML parsing problem while parsing
the input String
MBeanException - Wraps a distributed communication Exception.
DescriptorSupport
public DescriptorSupport(String[] fieldNames,
Object[] fieldValues)
throws RuntimeOperationsException
- Constructor taking field names and field values. Neither array
can be null.
- Parameters:
fieldNames - String array of field names. No elements of
this array can be null.fieldValues - Object array of the corresponding field
values. Elements of the array can be null. The
fieldValue must be valid for the
fieldName (as defined in method isValid)
Note: array sizes of parameters should match. If both arrays
are empty, then an empty descriptor is created.
- Throws:
RuntimeOperationsException - for illegal value for
field Names or field Values. The array lengths must be equal.
If the descriptor construction fails for any reason, this
exception will be thrown.
DescriptorSupport
public DescriptorSupport(String... fields)
- Constructor taking fields in the fieldName=fieldValue
format.
- Parameters:
fields - String array with each element containing a
field name and value. If this array is null or empty, then the
default constructor will be executed. Null strings or empty
strings will be ignored.
All field values should be Strings. If the field values are
not Strings, the programmer will have to reset or convert these
fields correctly.
Note: Each string should be of the form
fieldName=fieldValue. The field name
ends at the first = character; for example if the String
is a=b=c then the field name is a and its value
is b=c.
- Throws:
RuntimeOperationsException - for illegal value for
field Names or field Values. The field must contain an
"=". "=fieldValue", "fieldName", and "fieldValue" are illegal.
FieldName cannot be null. "fieldName=" will cause the value to
be null. If the descriptor construction fails for any reason,
this exception will be thrown.
getFieldValue
public Object getFieldValue(String fieldName)
throws RuntimeOperationsException
- Description copied from interface:
Descriptor
- Returns the value for a specific field name, or null if no value
is present for that name.
- Specified by:
getFieldValue in interface Descriptor
- Parameters:
fieldName - the field name.
- Returns:
- the corresponding value, or null if the field is not present.
- Throws:
RuntimeOperationsException - if the field name is illegal.
setField
public void setField(String fieldName,
Object fieldValue)
throws RuntimeOperationsException
- Description copied from interface:
Descriptor
Sets the value for a specific field name. This will
modify an existing field or add a new field.
The field value will be validated before it is set.
If it is not valid, then an exception will be thrown.
The meaning of validity is dependent on the descriptor
implementation.
- Specified by:
setField in interface Descriptor
- 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 if that is a valid value for the field.
- Throws:
RuntimeOperationsException - if the field name or field value
is illegal (wrapped exception is IllegalArgumentException); or
if the descriptor is immutable (wrapped exception is
UnsupportedOperationException).
getFields
public String[] getFields()
- Description copied from interface:
Descriptor
- Returns all of the fields contained in this descriptor as a string array.
- Specified by:
getFields in interface Descriptor
- 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, enclosed in parentheses,
used as the value for the field in the returned array. If the value
of a field is null, then the value of the field in the returned array
will be empty. If the descriptor is empty, you will get
an empty array. - See Also:
Descriptor.setFields(java.lang.String[], java.lang.Object[])
getFieldNames
public String[] getFieldNames()
- Description copied from interface:
Descriptor
- Returns all the field names in the descriptor.
- Specified by:
getFieldNames in interface Descriptor
- Returns:
- String array of field names. If the descriptor is empty,
you will get an empty array.
getFieldValues
public Object[] getFieldValues(String... fieldNames)
- Description copied from interface:
Descriptor
- 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.
- Specified by:
getFieldValues in interface Descriptor
- 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, as if the parameter were the array
returned by Descriptor.getFieldNames(). If a field name in the
array does not exist, including the case where it is null or
the empty string, then null is returned for the matching array
element being returned.
- Returns:
- Object array of field values. If the list of
fieldNames
is empty, you will get an empty array.
setFields
public void setFields(String[] fieldNames,
Object[] fieldValues)
throws RuntimeOperationsException
- Description copied from interface:
Descriptor
Sets all fields in the field names array to the new value with
the same index in the field values 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.
- Specified by:
setFields in interface Descriptor
- 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 - if the change fails for any reason.
Wrapped exception is IllegalArgumentException if
fieldNames or fieldValues is null, or if
the arrays are of different lengths, or if there is an
illegal value in one of them.
Wrapped exception is UnsupportedOperationException
if the descriptor is immutable, and the call would change
its contents.- See Also:
Descriptor.getFields()
clone
public Object clone()
throws RuntimeOperationsException
- Returns a new Descriptor which is a duplicate of the Descriptor.
- Specified by:
clone in interface Descriptor- Overrides:
clone in class Object
- Returns:
- a clone of this instance.
- Throws:
RuntimeOperationsException - for illegal value for
field Names or field Values. If the descriptor construction
fails for any reason, this exception will be thrown.- See Also:
Cloneable
removeField
public void removeField(String fieldName)
- Description copied from interface:
Descriptor
- Removes a field from the descriptor.
- Specified by:
removeField in interface Descriptor
- Parameters:
fieldName - String name of the field to be removed.
If the field name is illegal or the field is not found,
no exception is thrown.
equals
public boolean equals(Object o)
- Compares this descriptor to the given object. The objects are equal if
the given object is also a Descriptor, and if the two Descriptors have
the same field names (possibly differing in case) and the same
associated values. The respective values for a field in the two
Descriptors are equal if the following conditions hold:
- If one value is null then the other must be too.
- If one value is a primitive array then the other must be a primitive
array of the same type with the same elements.
- If one value is an object array then the other must be too and
Arrays.deepEquals
must return true.
- Otherwise
Object.equals(Object) must return true.
- Specified by:
equals in interface Descriptor- Overrides:
equals in class Object
- Parameters:
o - the object to compare with.
- Returns:
true if the objects are the same; false
otherwise.- See Also:
Object.hashCode(),
Hashtable
hashCode
public int hashCode()
Returns the hash code value for this descriptor. The hash
code is computed as the sum of the hash codes for each field in
the descriptor. The hash code of a field with name n
and value v is n.toLowerCase().hashCode() ^ h.
Here h is the hash code of v, computed as
follows:
- If
v is null then h is 0.
- If
v is a primitive array then h is computed using
the appropriate overloading of java.util.Arrays.hashCode.
- If
v is an object array then h is computed using
Arrays.deepHashCode.
- Otherwise
h is v.hashCode().
- Specified by:
hashCode in interface Descriptor- Overrides:
hashCode in class Object
- Returns:
- A hash code value for this object.
- See Also:
Object.equals(java.lang.Object),
Hashtable
isValid
public boolean isValid()
throws RuntimeOperationsException
- Returns true if all of the fields have legal values given their
names.
This implementation does not support interoperating with a directory
or lookup service. Thus, conforming to the specification, no checking is
done on the "export" field.
Otherwise this implementation returns false if:
- name and descriptorType fieldNames are not defined, or
null, or empty, or not String
- class, role, getMethod, setMethod fieldNames, if defined,
are null or not String
- persistPeriod, currencyTimeLimit, lastUpdatedTimeStamp,
lastReturnedTimeStamp if defined, are null, or not a Numeric
String or not a Numeric Value >= -1
- log fieldName, if defined, is null, or not a Boolean or
not a String with value "t", "f", "true", "false". These String
values must not be case sensitive.
- visibility fieldName, if defined, is null, or not a
Numeric String or a not Numeric Value >= 1 and <= 4
- severity fieldName, if defined, is null, or not a Numeric
String or not a Numeric Value >= 0 and <= 6
- persistPolicy fieldName, if defined, is null, or not one of
the following strings:
"OnUpdate", "OnTimer", "NoMoreOftenThan", "OnUnregister", "Always",
"Never". These String values must not be case sensitive.
- Specified by:
isValid in interface Descriptor
- Returns:
- true if the values are legal.
- Throws:
RuntimeOperationsException - If the validity checking
fails for any reason, this exception will be thrown.
toXMLString
public String toXMLString()
Returns an XML String representing the descriptor.
The format is not defined, but an implementation must
ensure that the string returned by this method can be
used to build an equivalent descriptor when instantiated
using the constructor DescriptorSupport(String inStr).
Fields which are not String objects will have toString()
called on them to create the value. The value will be
enclosed in parentheses. It is not guaranteed that you can
reconstruct these objects unless they have been
specifically set up to support toString() in a meaningful
format and have a matching constructor that accepts a
String in the same format.
If the descriptor is empty the following String is
returned: <Descriptor></Descriptor>
- Returns:
- the XML string.
- Throws:
RuntimeOperationsException - for illegal value for
field Names or field Values. If the XML formatted string
construction fails for any reason, this exception will be
thrown.
toString
public String toString()
- Returns a human readable string representing the
descriptor. The string will be in the format of
"fieldName=fieldValue,fieldName2=fieldValue2,..."
If there are no fields in the descriptor, then an empty String
is returned.
If a fieldValue is an object then the toString() method is
called on it and its returned value is used as the value for
the field enclosed in parenthesis.
- Overrides:
toString in class Object
- Returns:
- a string representation of the object.
- Throws:
RuntimeOperationsException - for illegal value for
field Names or field Values. If the descriptor string fails
for any reason, this exception will be thrown.
Copyright 2003 Sun Microsystems, Inc. All rights reserved
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