Support for Local Entity Enterprise JavaBeans(EJB)* in the Java2 Platform Enterprise Edition(J2EE)** client container to provide Object/Relational (O/R) mapping for two-tier applications that for performance reasons cannot work in a three-tier architecture where the EJB Container in the application server does the database access
Original Publication Date: 2005-Oct-11
Included in the Prior Art Database: 2005-Oct-11
The Java2 Platform Enterprise Edition (J2EE) architecture does not provide any support for running Enterprise JavaBeans (EJB) in a J2EE client. There is class of customers/clients (for example, clients doing genetic modeling) that have a need to use Object/Relational (O/R) mapping tools but cannot use the J2EE provided O/R mapping tools that are part of Container Managed Persistence (CMP) EJB offering. The reason they can't use the J2EE Application Server solution is because they need to access a lot of data from their database in order to render their models and going through the application server would make it very inefficient. As a result, these clients need to rely on other non-specification compliant O/R mapping tools that makes their code tied to a particular vendor's implementation.
Support for Local Entity Enterprise JavaBeans (EJB)* in the Java2 Platform Enterprise Edition(J2EE)** client container to provide Object /Relational (O/R) mapping for two-tier applications that for performance reasons cannot work in a three -tier architecture where the EJB Container in the application server does the database access
With EJB 2.0, the specification provides for application servers to provide local EJBs. Local EJBs are EJBs that can only be called within the Java Virtual Machine (JVM)*** in which they execute. The idea is to extend/modify the J2EE client container so that it can host and run Local EJBs. This way, the clients can use the standard EJB programming model as well as tools that are available in the distributed application server environment to generate O/R mappings between their local EJBs and their database. To make it really useful, the J2EE Application client should be extended to support both Session as well as Entity beans with local interfaces.
The advantage of this approach are:
The J2EE client application can use a standards based O/R mapping tool to generate and use a standards-based set of objects that can be consumed by the J2EE Application client in a standard way to build their business application of choice
The way this would work is as follows:
The customer would create the local EJBs for their J2EE client in the same way as they would have as if they were deploying it into an AppServer.
The EJB jar containing their local...