The Java Naming and Directory InterfaceTM (JNDI) is an application programming interface (API) that provides naming and directory functionality to applications written using the JavaTM programming language. It is defined to be independent of any specific directory service implementation. Thus a variety of directories--new, emerging, and already deployed--can be accessed in a common way.
ArchitectureThe JNDI architecture consists of an API and a service provider interface (SPI). Java applications use the JNDI API to access a variety of naming and directory services. The SPI enables a variety of naming and directory services to be plugged in transparently, thereby allowing the Java application using the JNDI API to access their services. See the following figure.
PackagingThe JNDI is included in the Java 2 SDK, v1.3 and later releases. It is also available as a Java Standard Extension for use with the JDK 1.1 and the Java 2 SDK, v1.2. It extends the v1.1 and v1.2 platforms to provide naming and directory functionality.
To use the JNDI, you must have the JNDI classes and one or more service providers. The Java 2 SDK, v1.3 includes three service providers for the following naming/directory services:
- Lightweight Directory Access Protocol (LDAP)
- Common Object Request Broker Architecture (CORBA) Common Object Services (COS) name service
- Java Remote Method Invocation (RMI) Registry
Other service providers can be downloaded from the JNDI Web site or obtained from other vendors. When using the JNDI as a Standard Extension on the JDK 1.1 and Java 2 SDK, v1.2, you must first download the JNDI classes and one or more service providers. See the Preparations lesson for details on how to install the JNDI classes and service providers.
The JNDI is divided into five packages: