The naming examples discussed how you can use
bind(), rebind(),
The
DirContext interface contains overloaded versions
of these methods that accept attributes.
You can use these
DirContext methods to associate
attributes with the object at the time that the binding or subcontext
is added to the namespace.
For example, you might create a
Person object and bind it to
the namespace and at the same time associate attributes about that
Person object.
DirContext.bind() is used to add a binding
that has attributes to a context.
It accepts as arguments the name of the object, the object
to be bound, and a set of attributes.
// Create the object to be bound
Fruit fruit = new Fruit("orange");
// Create attributes to be associated with the object
Attributes attrs = new BasicAttributes(true); // case-ignore
Attribute objclass = new BasicAttribute("objectclass");
objclass.add("top");
objclass.add("organizationalUnit");
attrs.put(objclass);
// Perform bind
ctx.bind("ou=favorite, ou=Fruits", fruit, attrs);
This example creates an object of class
Fruit
and binds it to the name
"ou=favorite" into the context named
"ou=Fruits",
relative to
ctx.
This binding has the
"objectclass" attribute.
If you subsequently looked up the name
"ou=favorite, ou=Fruits" in
ctx, then you would get the
fruit object.
If you then got the attributes of
"ou=favorite, ou=Fruits",
you would get those attributes with which the object was created.
Following is this example's output.
# java Bind
orange
attribute: objectclass
value: top
value: organizationalUnit
value: javaObject
value: javaNamingReference
attribute: javaclassname
value: Fruit
attribute: javafactory
value: FruitFactory
attribute: javareferenceaddress
value: #0#fruit#orange
attribute: ou
value: favorite
The extra attributes and attribute values shown are
used to store information about the object (fruit).
These extra attributes are discussed in more detail in the
trail.
If you were to run this example twice, then the second attempt would fail with a
NameAlreadyBoundException. This is because the name "ou=favorite" is already bound in the "ou=Fruits" context.
For the second attempt to succeed, you would have to use
rebind().
DirContext.rebind() is used to add or replace a binding
and its attributes.
It accepts the same arguments as
bind().
However,
rebind()'s semantics require that
if the name is already bound, then
it will be unbound and the newly given object and attributes
will be bound.
// Create the object to be bound
Fruit fruit = new Fruit("lemon");
// Create attributes to be associated with the object
Attributes attrs = new BasicAttributes(true); // case-ignore
Attribute objclass = new BasicAttribute("objectclass");
objclass.add("top");
objclass.add("organizationalUnit");
attrs.put(objclass);
// Perform bind
ctx.rebind("ou=favorite, ou=Fruits", fruit, attrs);
When you run
this example, it
replaces the binding that the
bind()
example created.
# java Rebind
lemon
attribute: objectclass
value: top
value: organizationalUnit
value: javaObject
value: javaNamingReference
attribute: javaclassname
value: Fruit
attribute: javafactory
value: FruitFactory
attribute: javareferenceaddress
value: #0#fruit#lemon
attribute: ou
value: favorite
