Clients Look Up Object Names with JNDI

An Oracle8 i client can look up a published object by name with CORBA COSNaming or with the simpler JNDI (Java Naming and Directory Interface) which interacts with COSNaming in the client's behalf.

A client creates an initial JNDI context for a particular database with a Java constructor, for example:

Context ic = new InitialContext(env); 

The env parameter specifies user name and password under which the client is logging in. Because object implementations run in database servers, CORBA object users (via their clients) must identify and authenticate themselves to the database as they would for any database operation.

To obtain an instance of a published implementation, the client calls the JNDI context's lookup() method, passing a URL that names the target database and the published name of the desired object implementation. The lookup() call returns a reference to an instance in the target database. A client may pass the reference (perhaps in stringified form) to other clients, and the reference will remain valid as long as the session in which the associated object was created survives. Clients that use copies of the same object reference share the object's database session.

If a client executes lookup() twice in succession with the same parameters, the second object reference is identical to the first, that is, it refers to the instance created by the first lookup() call. However, if a client creates a second session and does the second lookup() in that session, a different instance is created and its reference returned.

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