Java™ Application Development on Linux - Dator

21.3 What’s in a Name? An Introduction to JNDI48721.3.2.4 Novell Directory Service (NDS)Novell, the folks behind Netware, came up with NDS, which provides full directoryservices like LDAP/X.500, but (according to the computer press—letus confess right now that we have never directly used NDS or Microsoft’s ActiveDirectory) with a simpler API and easier administration. We don’t knowenough about it to comment on it. But we do know that JNDI can access it.21.3.2.5 Microsoft’s Active DirectoryWe have to do the same hand-waving here. Active Directory provides similarfunctionality to NDS and LDAP. We don’t know enough about it to commenton it. But, again, JNDI can talk to it.21.3.3 Putting a Face to a Name: JNDIThe Java Naming and Directory Interface package is designed to provide acommon way to access all of these disparate naming and directory services.The JNDI architecture consists of the JNDI API, which provides a consistentAPI, and a Service Provider Interface (SPI), which requires an instanceto connect to each naming service (such as DNS, LDAP, the RMI registry,and so on).Basic naming system functionality is obtained through the javax.namingpackage. Directory services are provided by the javax.naming.directorypackage.Since JNDI can span multiple naming and directory systems, there are noabsolute root contexts, so the InitialContext class exists to provide a basefrom which all other names and directories may be looked up.21.3.3.1 A Sample JNDI ProgramThe next couple of sections describe a very simple JNDI application that usesthe DNS Service Provider Interface to do directory operations on a DNSdomain. The source code for the class is shown in Example 21.1.