| JavaTM 2 Platform Std. Ed. v1.6.0
javax.naming.directory
Class BasicAttribute
java.lang.Object
 javax.naming.directory.BasicAttribute
- All Implemented Interfaces:
- Serializable, Cloneable, Attribute
public class BasicAttribute - extends Object
- implements Attribute
This class provides a basic implementation of the Attribute interface.
This implementation does not support the schema methods
getAttributeDefinition() and getAttributeSyntaxDefinition().
They simply throw OperationNotSupportedException.
Subclasses of BasicAttribute should override these methods if they
support them.
The BasicAttribute class by default uses Object.equals() to
determine equality of attribute values when testing for equality or
when searching for values, except when the value is an array.
For an array, each element of the array is checked using Object.equals().
Subclasses of BasicAttribute can make use of schema information
when doing similar equality checks by overriding methods
in which such use of schema is meaningful.
Similarly, the BasicAttribute class by default returns the values passed to its
constructor and/or manipulated using the add/remove methods.
Subclasses of BasicAttribute can override get() and getAll()
to get the values dynamically from the directory (or implement
the Attribute interface directly instead of subclassing BasicAttribute).
Note that updates to BasicAttribute (such as adding or removing a value)
does not affect the corresponding representation of the attribute
in the directory. Updates to the directory can only be effected
using operations in the DirContext interface.
A BasicAttribute instance is not synchronized against concurrent
multithreaded access. Multiple threads trying to access and modify a
BasicAttribute should lock the object.
- Since:
- 1.3
- See Also:
- Serialized Form
|
Field Summary |
protected String |
attrID
Holds the attribute's id. |
protected boolean |
ordered
A flag for recording whether this attribute's values are ordered. |
protected Vector<Object> |
values
Holds the attribute's values. |
|
Constructor Summary |
BasicAttribute(String id)
Constructs a new instance of an unordered attribute with no value. |
BasicAttribute(String id,
boolean ordered)
Constructs a new instance of a possibly ordered attribute with no value. |
BasicAttribute(String id,
Object value)
Constructs a new instance of an unordered attribute with a single value. |
BasicAttribute(String id,
Object value,
boolean ordered)
Constructs a new instance of a possibly ordered attribute with a
single value. |
|
Method Summary |
void |
add(int ix,
Object attrVal)
Adds an attribute value to the ordered list of attribute values. |
boolean |
add(Object attrVal)
Adds a new value to this attribute. |
void |
clear()
Removes all values from this attribute. |
Object |
clone()
Creates and returns a copy of this object. |
boolean |
contains(Object attrVal)
Determines whether a value is in this attribute. |
boolean |
equals(Object obj)
Determines whether obj is equal to this attribute. |
Object |
get()
Retrieves one of this attribute's values. |
Object |
get(int ix)
Retrieves the attribute value from the ordered list of attribute values. |
NamingEnumeration<?> |
getAll()
Retrieves an enumeration of this attribute's values. |
DirContext |
getAttributeDefinition()
Retrieves this attribute's schema definition. |
DirContext |
getAttributeSyntaxDefinition()
Retrieves the syntax definition associated with this attribute. |
String |
getID()
Retrieves the id of this attribute. |
int |
hashCode()
Calculates the hash code of this attribute. |
boolean |
isOrdered()
Determines whether this attribute's values are ordered. |
Object |
remove(int ix)
Removes an attribute value from the ordered list of attribute values. |
boolean |
remove(Object attrval)
Removes a specified value from this attribute. |
Object |
set(int ix,
Object attrVal)
Sets an attribute value in the ordered list of attribute values. |
int |
size()
Retrieves the number of values in this attribute. |
String |
toString()
Generates the string representation of this attribute. |
attrID
protected String attrID
- Holds the attribute's id. It is initialized by the public constructor and
cannot be null unless methods in BasicAttribute that use attrID
have been overridden.
values
protected transient Vector<Object> values
- Holds the attribute's values. Initialized by public constructors.
Cannot be null unless methods in BasicAttribute that use
values have been overridden.
ordered
protected boolean ordered
- A flag for recording whether this attribute's values are ordered.
BasicAttribute
public BasicAttribute(String id)
- Constructs a new instance of an unordered attribute with no value.
- Parameters:
id - The attribute's id. It cannot be null.
BasicAttribute
public BasicAttribute(String id,
Object value)
- Constructs a new instance of an unordered attribute with a single value.
- Parameters:
id - The attribute's id. It cannot be null.value - The attribute's value. If null, a null
value is added to the attribute.
BasicAttribute
public BasicAttribute(String id,
boolean ordered)
- Constructs a new instance of a possibly ordered attribute with no value.
- Parameters:
id - The attribute's id. It cannot be null.ordered - true means the attribute's values will be ordered;
false otherwise.
BasicAttribute
public BasicAttribute(String id,
Object value,
boolean ordered)
- Constructs a new instance of a possibly ordered attribute with a
single value.
- Parameters:
id - The attribute's id. It cannot be null.value - The attribute's value. If null, a null
value is added to the attribute.ordered - true means the attribute's values will be ordered;
false otherwise.
clone
public Object clone()
- Description copied from class:
Object
- Creates and returns a copy of this object. The precise meaning
of "copy" may depend on the class of the object. The general
intent is that, for any object x, the expression:
x.clone() != x
will be true, and that the expression:
x.clone().getClass() == x.getClass()
will be true, but these are not absolute requirements.
While it is typically the case that:
x.clone().equals(x)
will be true, this is not an absolute requirement.
By convention, the returned object should be obtained by calling
super.clone. If a class and all of its superclasses (except
Object) obey this convention, it will be the case that
x.clone().getClass() == x.getClass().
By convention, the object returned by this method should be independent
of this object (which is being cloned). To achieve this independence,
it may be necessary to modify one or more fields of the object returned
by super.clone before returning it. Typically, this means
copying any mutable objects that comprise the internal "deep structure"
of the object being cloned and replacing the references to these
objects with references to the copies. If a class contains only
primitive fields or references to immutable objects, then it is usually
the case that no fields in the object returned by super.clone
need to be modified.
The method clone for class Object performs a
specific cloning operation. First, if the class of this object does
not implement the interface Cloneable, then a
CloneNotSupportedException is thrown. Note that all arrays
are considered to implement the interface Cloneable.
Otherwise, this method creates a new instance of the class of this
object and initializes all its fields with exactly the contents of
the corresponding fields of this object, as if by assignment; the
contents of the fields are not themselves cloned. Thus, this method
performs a "shallow copy" of this object, not a "deep copy" operation.
The class Object does not itself implement the interface
Cloneable, so calling the clone method on an object
whose class is Object will result in throwing an
exception at run time.
- Specified by:
clone in interface Attribute- Overrides:
clone in class Object
- Returns:
- a clone of this instance.
- See Also:
Cloneable
equals
public boolean equals(Object obj)
- Determines whether obj is equal to this attribute.
Two attributes are equal if their attribute-ids, syntaxes
and values are equal.
If the attribute values are unordered, the order that the values were added
are irrelevant. If the attribute values are ordered, then the
order the values must match.
If obj is null or not an Attribute, false is returned.
By default Object.equals() is used when comparing the attribute
id and its values except when a value is an array. For an array,
each element of the array is checked using Object.equals().
A subclass may override this to make
use of schema syntax information and matching rules,
which define what it means for two attributes to be equal.
How and whether a subclass makes
use of the schema information is determined by the subclass.
If a subclass overrides equals(), it should also override
hashCode()
such that two attributes that are equal have the same hash code.
- Overrides:
equals in class Object
- Parameters:
obj - The possibly null object to check.
- Returns:
- true if obj is equal to this attribute; false otherwise.
- See Also:
hashCode(),
contains(java.lang.Object)
hashCode
public int hashCode()
- Calculates the hash code of this attribute.
The hash code is computed by adding the hash code of
the attribute's id and that of all of its values except for
values that are arrays.
For an array, the hash code of each element of the array is summed.
If a subclass overrides hashCode(), it should override
equals()
as well so that two attributes that are equal have the same hash code.
- Overrides:
hashCode in class Object
- Returns:
- an int representing the hash code of this attribute.
- See Also:
equals(java.lang.Object)
toString
public String toString()
- Generates the string representation of this attribute.
The string consists of the attribute's id and its values.
This string is meant for debugging and not meant to be
interpreted programmatically.
- Overrides:
toString in class Object
- Returns:
- The non-null string representation of this attribute.
getAll
public NamingEnumeration<?> getAll()
throws NamingException
- Retrieves an enumeration of this attribute's values.
By default, the values returned are those passed to the
constructor and/or manipulated using the add/replace/remove methods.
A subclass may override this to retrieve the values dynamically
from the directory.
- Specified by:
getAll in interface Attribute
- Returns:
- A non-null enumeration of the attribute's values.
Each element of the enumeration is a possibly null Object. The object's
class is the class of the attribute value. The element is null
if the attribute's value is null.
If the attribute has zero values, an empty enumeration
is returned.
- Throws:
NamingException - If a naming exception was encountered while retrieving
the values.- See Also:
Attribute.isOrdered()
get
public Object get()
throws NamingException
- Retrieves one of this attribute's values.
By default, the value returned is one of those passed to the
constructor and/or manipulated using the add/replace/remove methods.
A subclass may override this to retrieve the value dynamically
from the directory.
- Specified by:
get in interface Attribute
- Returns:
- A possibly null object representing one of
the attribute's value. It is null if the attribute's value
is null.
- Throws:
NamingException - If a naming exception was encountered while retrieving
the value.
size
public int size()
- Description copied from interface:
Attribute
- Retrieves the number of values in this attribute.
- Specified by:
size in interface Attribute
- Returns:
- The nonnegative number of values in this attribute.
getID
public String getID()
- Description copied from interface:
Attribute
- Retrieves the id of this attribute.
- Specified by:
getID in interface Attribute
- Returns:
- The id of this attribute. It cannot be null.
contains
public boolean contains(Object attrVal)
- Determines whether a value is in this attribute.
By default,
Object.equals() is used when comparing attrVal
with this attribute's values except when attrVal is an array.
For an array, each element of the array is checked using
Object.equals().
A subclass may use schema information to determine equality.
- Specified by:
contains in interface Attribute
- Parameters:
attrVal - The possibly null value to check. If null, check
whether the attribute has an attribute value whose value is null.
- Returns:
- true if attrVal is one of this attribute's values; false otherwise.
- See Also:
Object.equals(java.lang.Object),
equals(java.lang.Object)
add
public boolean add(Object attrVal)
- Adds a new value to this attribute.
By default, Object.equals() is used when comparing attrVal
with this attribute's values except when attrVal is an array.
For an array, each element of the array is checked using
Object.equals().
A subclass may use schema information to determine equality.
- Specified by:
add in interface Attribute
- Parameters:
attrVal - The new possibly null value to add. If null, null
is added as an attribute value.
- Returns:
- true if a value was added; false otherwise.
remove
public boolean remove(Object attrval)
- Removes a specified value from this attribute.
By default, Object.equals() is used when comparing attrVal
with this attribute's values except when attrVal is an array.
For an array, each element of the array is checked using
Object.equals().
A subclass may use schema information to determine equality.
- Specified by:
remove in interface Attribute
- Parameters:
attrval - The possibly null value to remove from this attribute.
If null, remove the attribute value that is null.
- Returns:
- true if the value was removed; false otherwise.
clear
public void clear()
- Description copied from interface:
Attribute
- Removes all values from this attribute.
- Specified by:
clear in interface Attribute
isOrdered
public boolean isOrdered()
- Description copied from interface:
Attribute
- Determines whether this attribute's values are ordered.
If an attribute's values are ordered, duplicate values are allowed.
If an attribute's values are unordered, they are presented
in any order and there are no duplicate values.
- Specified by:
isOrdered in interface Attribute
- Returns:
- true if this attribute's values are ordered; false otherwise.
- See Also:
Attribute.get(int),
Attribute.remove(int),
Attribute.add(int, java.lang.Object),
Attribute.set(int, java.lang.Object)
get
public Object get(int ix)
throws NamingException
- Description copied from interface:
Attribute
- Retrieves the attribute value from the ordered list of attribute values.
This method returns the value at the ix index of the list of
attribute values.
If the attribute values are unordered,
this method returns the value that happens to be at that index.
- Specified by:
get in interface Attribute
- Parameters:
ix - The index of the value in the ordered list of attribute values.
0 <= ix < size().
- Returns:
- The possibly null attribute value at index ix;
null if the attribute value is null.
- Throws:
NamingException - If a naming exception was encountered while
retrieving the value.
remove
public Object remove(int ix)
- Description copied from interface:
Attribute
- Removes an attribute value from the ordered list of attribute values.
This method removes the value at the ix index of the list of
attribute values.
If the attribute values are unordered,
this method removes the value that happens to be at that index.
Values located at indices greater than ix are shifted up towards
the front of the list (and their indices decremented by one).
- Specified by:
remove in interface Attribute
- Parameters:
ix - The index of the value to remove.
0 <= ix < size().
- Returns:
- The possibly null attribute value at index ix that was removed;
null if the attribute value is null.
add
public void add(int ix,
Object attrVal)
- Description copied from interface:
Attribute
- Adds an attribute value to the ordered list of attribute values.
This method adds attrVal to the list of attribute values at
index ix.
Values located at indices at or greater than ix are
shifted down towards the end of the list (and their indices incremented
by one).
If the attribute values are unordered and already have attrVal,
IllegalStateException is thrown.
- Specified by:
add in interface Attribute
- Parameters:
ix - The index in the ordered list of attribute values to add the new value.
0 <= ix <= size().attrVal - The possibly null attribute value to add; if null, null is
the value added.
set
public Object set(int ix,
Object attrVal)
- Description copied from interface:
Attribute
- Sets an attribute value in the ordered list of attribute values.
This method sets the value at the ix index of the list of
attribute values to be attrVal. The old value is removed.
If the attribute values are unordered,
this method sets the value that happens to be at that index
to attrVal, unless attrVal is already one of the values.
In that case, IllegalStateException is thrown.
- Specified by:
set in interface Attribute
- Parameters:
ix - The index of the value in the ordered list of attribute values.
0 <= ix < size().attrVal - The possibly null attribute value to use.
If null, 'null' replaces the old value.
- Returns:
- The possibly null attribute value at index ix that was replaced.
Null if the attribute value was null.
getAttributeSyntaxDefinition
public DirContext getAttributeSyntaxDefinition()
throws NamingException
- Retrieves the syntax definition associated with this attribute.
This method by default throws OperationNotSupportedException. A subclass
should override this method if it supports schema.
- Specified by:
getAttributeSyntaxDefinition in interface Attribute
- Returns:
- The attribute's syntax definition. Null if the implementation
supports schemas but this particular attribute does not have
any schema information.
- Throws:
OperationNotSupportedException - If getting the schema
is not supported.
NamingException - If a naming exception occurs while getting
the schema.
getAttributeDefinition
public DirContext getAttributeDefinition()
throws NamingException
- Retrieves this attribute's schema definition.
This method by default throws OperationNotSupportedException. A subclass
should override this method if it supports schema.
- Specified by:
getAttributeDefinition in interface Attribute
- Returns:
- This attribute's schema definition. Null if the implementation
supports schemas but this particular attribute does not have
any schema information.
- Throws:
OperationNotSupportedException - If getting the schema
is not supported.
NamingException - If a naming exception occurs while getting
the schema.
Copyright 2003 Sun Microsystems, Inc. All rights reserved
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