JNDI Connection Basics

The client example in Chapter 2 showed how to connect to Oracle, start a database server session, and activate an object using a single URL specification. This was performed through the following steps:

1. Hashtable env = new Hashtable();
2. env.put(javax.naming.Context.URL_PKG_PREFIXES, "oracle.aurora.jndi");
3. env.put(javax.naming.Context.SECURITY_PRINCIPAL, username);
4. env.put(javax.naming.Context.SECURITY_CREDENTIALS, password);
5. env.put(javax.naming.Context.SECURITY_AUTHENTICATION, 

	ServiceCtx.NON_SSL_LOGIN);
6. Context ic = new InitialContext(env);
7. myHello hello =
    (myHello) ic.lookup("sess_iiop://localhost:2481:ORCL/test/myHello");
8. System.out.println(hello.helloWorld());

In this example, there are four basic operations:

• Lines 1-5 set up an environment for the JNDI initial context.

• Line 6 creates the JNDI initial context.

• Line 7 looks up a published object. (See "URL Syntax" for a discussion of the URL syntax.)

• Line 8 invokes a method on the object.

When a client looks up an object through the JNDI lookup method, the client and server automatically perform the following logic:

• A session IIOP connection is created to the ORCL instance of the local host database.

• The server establishes a database session.

• The client is authenticated, using the NON_SSL_LOGIN protocol, with the username and password specified in the environment context.

• The published object, /test/myHello, is located in the session namespace and a reference to it is returned to the client.

When the client invokes a method--such as helloWorld()--on the returned reference, the server activates the object in the server.

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