Java EE client

The Java EE client is a Java EE mode of using the runtime environment of either an Application Client installation or a WebSphere Application Server installation. The Java EE client uses the Client Container in the runtime environment to simplify access to system services such as security, transactions, naming, and database access for use by Java EE client applications.

The Java EE client is sometimes referred to as the "Java EE application client" or "J2EE application client".

The Client Container enables Java EE client applications to use logical names ("nicknames") for enterprise beans and local resources, and to leave the resolution of those names to a look up in the JNDI namespace of an application server. Besides simplifying resolution to enterprise beans and local resources references, this use of logical names and JNDI lookups eliminates changes to the client application code if the underlying object or resource either changes or moves to a different application server.

The Java EE client initializes the runtime environment for a Java EE client application. A deployment descriptor defines the unique initialization for a client application, and defines the logical names used by the application.

The logical names are defined within the deployment descriptor of a Java EE client application. These logical deployment descriptors identify enterprise beans or local resources (JDBC data sources, J2C connection factories, Java Message Service (JMS) resources, and JavaMail and URL APIs) for simplified resolution through JNDI lookup.

Storing the resource information separately from the client application program makes the client application program portable and more flexible. If we develop a client application using and adhering to the Java EE platform, we can port the client application from one Java EE platform implementation to another. The code of the client application does not change, but the application package might need redeployment using the deployment tool of the new Java EE platform.

The Java EE client does not support connection pools. The application client calls the database directly, without a datasource. To use the getConnection() request from a Java EE client application, configure the JDBC provider in the application deployment descriptors, using Rational Application Developer or an assembly tool. The connection is established between the client application and the database.

The Java EE client uses the Java Remote Method Invocation technology over Internet Inter-Orb Protocol (RMI-IIOP). Using this protocol enables a Java EE client application to access enterprise bean references and to use Common Object Request Broker Architecture (CORBA) services provided by the Java EE client runtime. Use of the RMI-IIOP protocol and the accessibility of CORBA services assist users in developing a Java EE client application that requires access to both enterprise bean references and CORBA object references.

Developing a Java EE client application