Module java.naming
Package javax.naming.directory

Interface DirContext

All Superinterfaces:
Context
All Known Subinterfaces:
EventDirContext, LdapContext
All Known Implementing Classes:
InitialDirContext, InitialLdapContext
public interface DirContext extends Context
The directory service interface, containing methods for examining and updating attributes associated with objects, and for searching the directory.

Names

Each name passed as an argument to a DirContext method is relative to that context. The empty name is used to name the context itself. The name parameter may never be null.

Most of the methods have overloaded versions with one taking a Name parameter and one taking a String. These overloaded versions are equivalent in that if the Name and String parameters are just different representations of the same name, then the overloaded versions of the same methods behave the same. In the method descriptions below, only one version is documented. The second version instead has a link to the first: the same documentation applies to both.

See Context for a discussion on the interpretation of the name argument to the Context methods. These same rules apply to the name argument to the DirContext methods.

Attribute Models

There are two basic models of what attributes should be associated with. First, attributes may be directly associated with a DirContext object. In this model, an attribute operation on the named object is roughly equivalent to a lookup on the name (which returns the DirContext object), followed by the attribute operation invoked on the DirContext object in which the caller supplies an empty name. The attributes can be viewed as being stored along with the object (note that this does not imply that the implementation must do so).

The second model is that attributes are associated with a name (typically an atomic name) in a DirContext. In this model, an attribute operation on the named object is roughly equivalent to a lookup on the name of the parent DirContext of the named object, followed by the attribute operation invoked on the parent in which the caller supplies the terminal atomic name. The attributes can be viewed as being stored in the parent DirContext (again, this does not imply that the implementation must do so). Objects that are not DirContexts can have attributes, as long as their parents are DirContexts.

JNDI support both of these models. It is up to the individual service providers to decide where to "store" attributes. JNDI clients are safest when they do not make assumptions about whether an object's attributes are stored as part of the object, or stored within the parent object and associated with the object's name.

Attribute Type Names

In the getAttributes() and search() methods, you can supply the attributes to return by supplying a list of attribute names (strings). The attributes that you get back might not have the same names as the attribute names you have specified. This is because some directories support features that cause them to return other attributes. Such features include attribute subclassing, attribute name synonyms, and attribute language codes.

In attribute subclassing, attributes are defined in a class hierarchy. In some directories, for example, the "name" attribute might be the superclass of all name-related attributes, including "commonName" and "surName". Asking for the "name" attribute might return both the "commonName" and "surName" attributes.

With attribute type synonyms, a directory can assign multiple names to the same attribute. For example, "cn" and "commonName" might both refer to the same attribute. Asking for "cn" might return the "commonName" attribute.

Some directories support the language codes for attributes. Asking such a directory for the "description" attribute, for example, might return all of the following attributes:

  • description
  • description;lang-en
  • description;lang-de
  • description;lang-fr

Operational Attributes

Some directories have the notion of "operational attributes" which are attributes associated with a directory object for administrative purposes. An example of operational attributes is the access control list for an object.

In the getAttributes() and search() methods, you can specify that all attributes associated with the requested objects be returned by supply null as the list of attributes to return. The attributes returned do not include operational attributes. In order to retrieve operational attributes, you must name them explicitly.

Named Context

There are certain methods in which the name must resolve to a context (for example, when searching a single level context). The documentation of such methods use the term named context to describe their name parameter. For these methods, if the named object is not a DirContext, NotContextException is thrown. Aside from these methods, there is no requirement that the named object be a DirContext.

Parameters

An Attributes, SearchControls, or array object passed as a parameter to any method will not be modified by the service provider. The service provider may keep a reference to it for the duration of the operation, including any enumeration of the method's results and the processing of any referrals generated. The caller should not modify the object during this time. An Attributes object returned by any method is owned by the caller. The caller may subsequently modify it; the service provider will not.

Exceptions

All the methods in this interface can throw a NamingException or any of its subclasses. See NamingException and their subclasses for details on each exception.

Since:
1.3
See Also: