- Standalone Enterprise Applications
- Application Server-Based Enterprise Applications
- Application Server Architecture Provider Roles
- Application Server Components
- Application Server Client Interfaces
- Application Server Client Implementations
- Enterprise Application Configuration and Deployment
- Application Service Management
Application Server Client Interfaces
Enterprise application components are written to provide some type of service to enterprise application clients. Thus, application server environments must define some way for clients to tap the services of these components. The mechanism by which application servers offer these services works via some distributed application service interface. These are the basic client interface problems that application servers must solve:
Distributed business-specific interfacesThe application service interface needs to expose only the business-specific operations defined on a component that have been specified as distributable.
Distributed business-specific naming and life cycle ManagementThe application service interface must provide a means for clients to look up, create, and destroy component instances and references.
Interface definition languageThe application service interface must utilize some language for defining interfaces usable by clients.
Interface communications protocolThe application service interface must utilize some underlying communications protocol usable by clients.
To satisfy these needs, J2EE application service frameworks define standards for creating client interfaces to EJB components. These corresponding standards include the following:
EJB remote interfacesEJB remote interfaces define the business-specific operations that are distributed to EJB clients.
EJB home interfaces and JNDIEJB home interfaces define business-specific and standard means for creating and destroying EJB components, as well as for looking up certain EJB component instances. JNDI is also used to obtain initial EJB home interface handles.
Java and IDLBecause EJB depends on RMI, Java-based EJB client interfaces can be defined. Additionally, CORBA IDL EJB client interfaces can also be defined via a CORBA-to-EJB mapping.
Internet Interoperability Protocol (IIOP)The standard protocol over which EJB clients communicate with EJB application server environments is IIOP.