Initial context support

All naming operations begin with obtaining an initial context. We can view the initial context as a starting point in the namespace. Use the initial context to perform naming operations, such as looking up and binding objects in the namespace.

 

Initial contexts registered with the ORB as initial references

The server root, cell persistent root, cell root, and node root are registered with the name server's ORB and can be used as an initial context. An initial context is used by CORBA and enterprise bean applications as a starting point for namespace lookups. The keys for these roots as recognized by the ORB are shown in the following table:

Root Context	Initial Reference Key
Server Root	NameServiceServerRoot
Cell Persistent Root	NameServiceCellPersistentRoot
Cell Root	NameServiceCellRoot, NameService
Node Root	NameServiceNodeRoot

A server root initial context is the server root context for the specific server we are accessing. Similarly, a node root initial context is the node root for the server being accessed.

Use the previously mentioned keys in CORBA INS object URLs (corbaloc and corbaname) and as an argument to an ORB resolve_initial_references call. For examples, see CORBA and JNDI programming examples, which show how to get an initial context.

 

Default initial contexts

The default initial context depends on the type of client. Different categories of clients and the corresponding default initial context follow.

• WAS V5 and later JNDI interface implementation

  The JNDI interface is used by EJB applications to perform namespace lookups. WAS clients by default use the WAS CosNaming JNDI plug-in implementation. The default initial context for clients of this type is the server root of the server specified by the provider URL. For more details, refer to the JNDI programming examples on getting initial contexts.

• Other JNDI implementation

  Some applications can perform namespace lookups with a non-product CosNaming JNDI plug-in implementation. Assuming the key NameService is used to obtain the initial context, the default initial context for clients of this type is the cell root.

• CORBA

  The standard CORBA client obtains an initial org.omg.CosNaming.NamingContext reference with the key NameService. The initial context in this case is the cell root.

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Related concepts

Naming
Namespace logical view

 

Related tasks

Use naming
Develop applications that use JNDI
Develop applications that use CosNaming (CORBA Naming interface)

 

Related

Example: Getting the default initial context
Example: Getting an initial context by setting the provider URL property
Example: Getting an initial context with CosNaming