You need a Java run-time system on any machine that is going to execute Java applications. If you are going to develop mixed Java and COBOL applications, you also need a Java development environment. You can use either the Java Software Development Kit (SDK) available from Sun, or any Java IDE which is based on either the Sun or Microsoft Java run-time environments. Alternatively you can have a Java Virtual Machine (JVM), which provides both a development environment and a run-time environment.
Your COBOL development system currently supports several Java run-time systems.
Before you start writing COBOL and Java programs which interact, you need to set up the following environment variables for the COBOL and Java run-time systems:
If you have COBOL programs that call Java, you must tell the COBOL run-time system which Java run-time system you are using. To do this, set environment variable COBJVM.
Use this method to override the default value, for example, if you are developing new applications with a later JVM, while still working with existing applications developed using an earlier JVM.
If you are using the Sun Java run-time system, the jvm.dll file must be available. Do not move jvm.dll to a different location, because it has dependencies on other files shipped as part of the Sun Java run-time system. The location of this file depends on which version of the JDK you are using. To ensure the file is available, add it to the system PATH. For example:
set path=jdk-install-directory\bin\subdirectory;%path%
Where subdirectory might be client, classic, hotspot or server.
If you have Java programs that call COBOL, you need to provide access to the Java classes that interface to the COBOL run-time system. To do this, ensure that mfcobol.jar is specified by the CLASSPATH environment variable. For example:
set classpath=install-directory\base\bin\mfcobol.jar;%classpath%;.;
Alternatively, you can set the classpath when you run a Java program, using the -classpath switch. For example:
java -classpath ".;install-directory\base\bin\mfcobol.jar;%classpath%" MyClass
The operating system's shared library path must include the directory containing libjava. This is often found in a subdirectory of Java's jre/lib directory, although the name of this directory is specific to each platform. On some platforms, you might need to specify more than one directory for this, for example, an additional directory containing the Java native threading support.