Java Naming and Directory Interface (JNDI)

Java Naming and Directory Interface (JNDI)

J2EE or J2SE? JNDI works with both
JNDI, the Java Naming and Directory Interface, allows applications to access various naming and directory services via a common interface. The figure below shows the JNDI architecture. Like JDBC (Java Database Connectivity), JNDI is not a service, but a set of interfaces; it allows applications to access many different directory service providers using a standardized API. Just as with JDBC, the JDK contains the JNDI interfaces but does not include a JNDI service provider -- although Sun Microsystems provides adapters for connecting to existing directory service providers, such as LDAP (lightweight directory access protocol), DNS (domain name service), and CORBA. However, you can use one of several free or open source JNDI providers in your J2SE (Java 2 Platform, Standard Edition) applications.
Brian Goetz, April 2002

Integrate EJBs with CORBA
Interoperability between EJBs (Enterprise JavaBeans) and CORBA is important for integrating Java- and non-Java-based applications. This article shows how to achieve integration between an EJB and a CORBA C++ application. It points to several important integration areas, particularly those in which EJBs use methods with Java built-in or user-defined objects as their parameters and return values.
Matjaz B. Juric, March 2002

Java Tip 118: Utilize the EjbProxy
This tip introduces you to the EjbProxy utility class. It instantiates and invokes a remote EJB without coupling your code directly to a specific implementation of that particular EJB.
Gorsen Huang, October 2001

The art of EJB deployment
It's no wonder the EJB specification calls for the role of an EJB deployer. Deploying EJBs can be a time-consuming task, and designing blueprints for universally deployable EJBs can be an even greater challenge. Application servers differ in how they prepare and deploy EJBs. This article tackles the issues you might encounter when deploying the same EJB code on different application servers -- namely BEA's WebLogic, IBM's WebSphere, and the open source community's JBoss. In addition, it highlights some preparation techniques for your EJB deployment.
James Caple and <a Href="javascript:openbrwindow()">mike Haim Altarace</a>, August 2001

The magic of Merlin
This technical overview will give you insight into the various new features and APIs of the upcoming JDK 1.4 -- code-named Merlin. The beta version is expected to be released this month. (3,000 words)
Vinay Aggarwal, March 2001

J2EE clustering, Part 1
If you plan to build a scalable and highly available Website, you need to understand clustering. In this article, Abraham Kang introduces J2EE clustering, shows how to implement clusters, and examines how Bluestone Total-e-server, Sybase Enterprise Application Server, SilverStream Application Server, and WebLogic Application Server differ in their approaches. With this knowledge you will be able to design and implement effective and efficient J2EE applications. (5,900 words)
Abraham Kang, February 2001

Get disconnected with CachedRowSet
The new CachedRowSet, still in early access release, provides benefits that developers can begin to take advantage of right away. Taylor Cowan demonstrates how you can use a CachedRowSet as the data model for a JavaServer Pages (JSP) entry/edit form. Assuming that you have some experience with JSP development, he describes step by step how to implement navigation, updates, inserts, and deletes using a CachedRowSet JavaBean. In addition, he shows how the CachedRowSet helps to reduce database-update SQL statements and the use of valuable database connection resources. (2,100 words)
Taylor G. Cowan, February 2001

Dive into connection pooling with J2EE
Connection pooling is a technique used for sharing server resources among requesting clients. This article focuses on support for connection pooling of both database resources and nondatabase resources in a J2EE environment. Siva examines the JDBC 2.0, JMS 1.02, JNDI 1.2 Standard Extension APIs with regard to connection pooling and looks at some existing vendor implementations of those APIs. He then looks at the upcoming J2EE Connector Architecture 1.0 that would support a vendor-independent/pluggable approach to managing resource connections. (2,000 words)
Siva Visveswaran, October 2000

Frameworks save the day
Every Enterprise Java project has the same basic plumbing. By embracing this premise, you can cut project costs and improve software quality in one swoop. Even the lightweight framework outlined in this article can add significant value to your project -- with immediate gains. And it's designed to be extensible and vendor-neutral, which makes it all the more valuable. We'll look at some basic components to demonstrate how you can add new services easily while maintaining a consistent API to developers using the framework, thus ensuring future extensibility. We'll also look at the issues pertaining to cross-application server portability. (3,200 words)
Humphrey Sheil, September 2000

Oracle8i's ORB does the trick
This article provides an in-depth overview of developing scalable and secure server-side Java CORBA applications using Oracle8i JVM and ORB. Also, session-based IIOP is introduced. Extensive security mechanisms make it easy to develop highly secure and flexible applications. A simple and easy-to-use JNDI interface is also provided to the name service. Since the Oracle8i ORB runs in the database, the desired load balancing and high scalability can be taken for granted. We'll also briefly touch on the general Oracle8i server framework, with which developers can write their own client/server protocols or component models using the scalability and performance of Oracle8i. Future releases of the ORB will include more sophisticated features like POA, objects by value, and bi-directional GIOP. (3,300 words)
Sastry K. Malladi, July 2000

JNDI overview, Part 3: Advanced JNDI
A JNDI service can be much more than a computerized card catalog. JNDI's object-storage capabilities allow it to play the role of resource administrator in your distributed applications and to provide simple, manageable object persistence. In recognition of its potential, the architects of key Java technologies such as JDBC and EJB built JNDI into their specifications. This month Todd Sundsted shows you how to store objects in a JNDI service. (1,900 words)
Todd Sundsted, March 2000

JNDI overview, Part 2: An introduction to directory services
As applications become more distributed, the efficient management and distribution of the information upon which they depend becomes more and more of a problem. Directory services such as LDAP (the Lightweight Directory Access Protocol) address this problem. For Java applications, the Java Naming and Directory Interface (JNDI) provides a generic interface to LDAP and other directory services. This month, Todd Sundsted introduces you to JNDI directory services. (1,300 words)
Todd Sundsted, February 2000

Use JNDI to share objects between different virtual machines
Imagine the following: Process A on machine B puts an object into a Hashtable. Now, a separate process C on a different machine D can access that object from its own local copy of the Hashtable -- even after process A terminates and the virtual machine unloads! Now imagine all this is achieved without the use of RMI, and without involving an ORB, CORBA, EJB, or a database. What's the secret? The Java Naming and Directory Interface (JNDI). This month's tool is the JNDIHashtable -- which, as its name reveals, uses JNDI to do its thing. (2,600 words)
Thomas E. Davis, July 1999

The state of Java middleware, Part 2: Enterprise JavaBeans
By the time Sun released version 1.0 of the Enterprise JavaBeans (EJB) specifications in March of 1998, several vendors not only had endorsed this new server-side component architecture, but also had begun developing products based on the evolving specifications. Today there are several products that fully implement the required features of EJB 1.0, and some that also support optional EJB features. This article provides an overview of EJB and looks at how some of these products support EJB. If you have wondered what EJB is or have bits and pieces of information about it but are missing the big picture, you need to read this article. Bonus: Includes a Middleware and EJB Glossary. (9,000 words)
Anil Hemrajani, April 1999