Micro Focus Visual COBOL 2.3 for Eclipse (Windows) > Programming > Using COBOL and Java Together > Setting Up the Environment for Native COBOL Applications > Setting Up the Environment for Java and COBOL

Setting Up the Environment for Java and COBOL

Restriction: This applies to native code only.

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 will need the Java Software Development Kit (SDK) available from Oracle.

Your COBOL development system currently supports several Java run-time systems.

For UNIX environments

To run COBOL and Java together, you need to use the Java/COBOL application launcher, cobjrun, instead of the java or cobrun triggers.

The JDK install location must be included on PATH. If the JAVA_HOME environment variable is set to the Java install location, then cobjrun uses it in preference to the Java install location which is included on PATH.

Note:

Make sure the cobsetenv script has been run after the installation of the product as described in the install readme. The script sets or modifies the following environment variables: COBDIR, PATH, CLASSPATH and LD_LIBRARY_PATH (or LIBPATH on AIX).
On AIX, cobjrun requires that the OS Thread Stack Size is greater than 192k. If this value is lower than 192k, you must execute cobjrun run with the -Xmso192k option - for example, cobjrun -Xmso192k main.
To check what the OS Thread Stack Size is, executing the following at a terminal: java -verbose:sizes. The OS Thread Stack Size is the number nnn for the "-Xmsonnn" option.

For Windows environments

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:

PATH
If you are using the Java run-time system from Oracle, 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 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.
CLASSPATH
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
```
Shared library path
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.

All platforms

If you are developing a Java or JVM project, you do not have to set the Java installation directory using the JAVA_HOME variable. Follow these steps to identify the JRE or JDK using the Properties dialog boxes:

Select your project in the Navigator pane.
On the Project menu, click Properties.
The Properties for <project-name> dialog box appears.
Select one of the following:
- For a COBOL JVM project, click Micro Focus > JVM Build Path.
- For a Java project, click Java Build Path.
Click the Libraries tab.
Select JRE System Library and click Edit.
Select Alternate JRE, click Installed JREs, then select an installed JRE or JDK and click OK.
Note: Click Add and use the Add JRE wizard to add a JRE or JDK that is not listed.
Click Finish, then click OK.