Run-time configurations

EGL allows you to generate a Java program for any of several supported platforms. You can deploy the program outside of J2EE or in the context of any of the following J2EE containers--

In addition, EGL provides a way to define a Web application that has the following characteristics:

For details on this specialized support for Web applications, see PageHandler part.

Finally, you can use EGL to generate a Java wrapper, as described in the next section.

Use of a Java wrapper

The EGL-generated Java wrapper is a set of classes that let you invoke an EGL-generated program from non-EGL-generated Java code; for example, from an action class in a Struts- or JSF-based J2EE web application or from a non-J2EE Java program. The Java-to-EGL integration task is as follows:

Generate Java wrapper classes, which are specific to a generated program
Incorporate those wrapper classes into the non-generated Java code
From the non-generated Java code, invoke the wrapper-class methods to make the actual call and to convert data between these two formats:
- The data-type formats used by Java
- The primitive-type formats required when passing data to and from the EGL-generated program

Valid calls

The next table shows the valid calls to or from the EGL-generated code.

Calling object	Called object
An EGL-generated Java wrapper in a Java class that is outside of J2EE	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated EJB session bean
	A CICS COBOL program that was generated by VisualAge Generator
An EGL-generated Java wrapper in a J2EE application client	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated EJB session bean
	A CICS COBOL program that was generated by VisualAge Generator
An EGL-generated Java wrapper in a J2EE Web application	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated Java program in the same J2EE Web application
	An EGL-generated EJB session bean
	A CICS COBOL program that was generated by VisualAge Generator
An EGL-generated Java program that is outside of J2EE	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated EJB session bean
	A CICS COBOL program that was generated by VisualAge Generator
	A non-EGL-generated program that was written in C or C++
	A non-generated program that was written in any language and runs under CICS
An EGL-generated Java program that is in a J2EE application client	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated EJB session bean
	An EGL-generated CICS COBOL program
	A non-generated program that was written in any language and runs under CICS
	A non-generated program that was written in C or C++
An EGL-generated Java program in a J2EE Web application	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated Java program in the same J2EE Web application
	An EGL-generated EJB session bean
	A CICS COBOL program that was generated in VisualAge Generator
	A non-generated program written in C or C++
An EGL-generated EJB session bean	An EGL-generated Java program (non-J2EE)
	An EGL-generated Java program in a J2EE application client
	An EGL-generated EJB session bean
	A CICS COBOL program that was generated by VisualAge Generator
	A non-generated program written in C or C++

Valid transfers

The next table shows the valid transfers to or from EGL-generated code.

Transferring object	Receiving object
An EGL-generated Java program that is outside of J2EE	An EGL-generated Java program (non-J2EE)
An EGL-generated Java program that is in a J2EE application client	An EGL-generated Java program in the same J2EE application client
An EGL-generated Java program in a J2EE Web application	An EGL-generated Java program in the same J2EE Web application