The Virtual Enterprise (VE) provides a unified platform for application development and integration. Even though VE is not an Enterprise Application Integration (EAI) platform, it provides a framework for plugging in existing application logic and making it available to other VE applications. VE 3.0 supports integrating existing Java™ classes, EJBs, Web services, CORBA servers, and relational databases. Other types of integration, including a proprietary system, can be easily added by implementing the VE External Resource Framework.
For starters, Java classes that are loaded in the same Java Virtual Machine (JVM) as the VE/Server are immediately available to be used in any VE rule. This includes instantiating a Java class, and calling any of its operations or static methods. In addition, when using the Java implementation for a VE process, any Java class in the same JVM can readily be used.
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 As far as integrating existing Enterprise JavaBeans (EJBs), the VE/Designer supports the import of beans into a VE package. Accordingly, it creates the appropriate objects and processes, and makes them available to the rest of the application as if they were hand built in VE. The EJB implementation is used to carry out the actual communication with the beans.
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 VE/Designer also includes a Web services import tool, where it creates the objects and processes accordingly with the specified WSDL, and makes them available to the rest of the application. The Web service implementation is used to carry out the actual communication with the services.
VE/Designer can be used to quickly integrate one or more Web services, maybe some EJBs, add additional behavior and functionality, and serve them as new Web services and/or browser applications. All without writing any code or knowing the details of the underlying technologies.
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| As discussed in the Database Deployment pages, VE/Designer supports several approaches for database interaction. To quickly access existing databases, add new logic, and expose the functionality as Web services or browser application, associating the SQL implementation with a VE process, instead of the default activity diagram, is sometimes the most suitable. The SQL implementation supports embedding SQL statements (both query and update), embedding a new stored procedure (VE will auto deploy to the target database), or referencing an already available stored procedure. In addition, the SQL implementation provides caching, and object-relational mapping facilities. |
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VE/Designer provides the same approach and tools for application development as it does for integration. Once a VE/Designer import tool is used to integrate an existing system or service, the imported logic or data access is available to the rest of the application logic as the same type of artifacts: objects, processes and rules. The actual implementation of the imported logic is completely transparent.
Further, VE/Designer supports providing alternate implementations to the same piece of logic (e.g. process). The actual implementation is determined in runtime and can be altered by using the VE/Administration Console without affecting the application logic. For example, the same process can have an activity model as a local implementation, an EJB implementation, and maybe an implementation to a remote Web service. Depending on the specific deployment configuration (i.e. resource policies), the appropriate implementation would be selected.
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