Enterprise JavaBeans, Second Edition

The EJB Client-Side API

Enterprise bean developers are required to provide a bean class, two remote interfaces, and for entity beans, a primary key class. Of these types, the remote interfaces and primary key class are visible to the client, while the bean class is not. The remote interface, home interface, and primary key contribute to the client-side API in EJB. The methods defined in these types as well as the methods of their supertypes provide the mechanisms that clients use to interact with an EJB business system.

The following sections examine in more detail the home interface, the remote interface, and the primary key, as well as other types that make up EJB’s client-side API. This will provide you with a better understanding of how the client-side API is used and its relationship with the bean class on the EJB server.

EJB 1.1: Java RMI-IIOP Conformance Requirement

Enterprise JavaBeans 1.0 defines its distributed interfaces in terms of Java RMI. RMI assumes that both the client and server are Java applications, so it takes full advantage of Java types as arguments and return values. Enterprise JavaBeans 1.1 also defines its distributed interfaces in terms of Java RMI, but it enforces compliance with CORBA’s interface, reference, and value types by requiring that only Java RMI-IIOP types be used. In other words, the underlying protocol can be anything that the vendor wants as long as it supports the types of interfaces and arguments specified by Java RMI-IIOP. In a future ...