What Is an Enterprise Bean?
Written in the Java programming language, an enterprise bean is a
server-side component that encapsulates the business logic of an
application. The business logic is the code that fulfills the purpose of
the application. In an inventory control application, for example, the
enterprise beans might implement the business logic in methods called
The following topics are addressed here:
Benefits of Enterprise Beans
For several reasons, enterprise beans simplify the development of large, distributed applications. First, because the EJB container provides system-level services to enterprise beans, the bean developer can concentrate on solving business problems. The EJB container, rather than the bean developer, is responsible for system-level services, such as transaction management and security authorization.
Second, because the beans rather than the clients contain the application’s business logic, the client developer can focus on the presentation of the client. The client developer does not have to code the routines that implement business rules or access databases. As a result, the clients are thinner, a benefit that is particularly important for clients that run on small devices.
Third, because enterprise beans are portable components, the application assembler can build new applications from existing beans. Provided that they use the standard APIs, these applications can run on any compliant Java EE server.
When to Use Enterprise Beans
You should consider using enterprise beans if your application has any of the following requirements.
Types of Enterprise Beans
Table 35-1 summarizes the two types of enterprise beans. The following sections discuss each type in more detail.
Table 35-1 Enterprise Bean Types