Before you write any Java™ client programs, update the CLASSPATH environment variable to include the jar files supplied with CICS® Transaction Gateway. For example, on Windows®:
CLASSPATH = <install_path>\classes\ctgclient.jar; <install_path>\classes\ctgserver.jar
The ctgserver.jar file is required in CLASSPATH only for JavaGateways using the local URL.
For more information on setting CLASSPATH, see the CICS Transaction Gateway: Administration book for your operating system.