Overview of Calling Java from Native OO COBOL

Micro Focus Java support enables you to send messages to Java objects from native OO COBOL programs and classes.

Java is supported through a Java domain in native OO COBOL. The Java domain enables you to declare Java classes inside a COBOL program. You can then send messages to the Java classes. The Java domain support works by creating a COBOL proxy object for each Java object, as shown in the figure below. The class itself that you declare is a proxy for the static methods of the Java class.

Your program needs to have a Repository paragraph, and needs to use the INVOKE verb each time you want to call a Java method, although it does not have to be written as an native OO COBOL class.

The COBOL run-time system converts parameters sent with messages from COBOL data types to Java data types. If a method returns a parameter, it is converted from a Java data type to a COBOL data type.

Using the techniques described in this chapter, you can call any Java API, such as JDBC, Sockets and Swing.

You need to have at least a basic knowledge of the Java language to be able to use this technology effectively. The Java Web site is a good starting place.

You can also call COBOL programs from Java without using the native OO COBOL Java domain.