Java Generic Security Services (Java GSS-API) is used for securely exchanging messages between communicating applications.
See Java GSS-API and JAAS Tutorials for Use with Kerberos in the JDK 8 documentation for a series of tutorials demonstrating various aspects of Java Authentication and Authorization Service (JAAS) and Java Generic Security Services Application Program Interface (GSS-API).
See Single Sign-on Using Kerberos in Java in the JDK 8 documentation for more information about how to use single sign-on based on the Kerberos V5 protocol.
See Java GSS Advanced Security Programming in the JDK 8 documentation for exercises that show you to use the Java GSS-API to build applications that authenticate users, communicate securely with other applications and services, and configure applications in a Kerberos environment to achieve Single Sign-On. In addition, these exercises show you how to use stronger encryption algorithms in a Kerberos environment and Java GSS mechanisms, such as SPNEGO, to secure the association.
See The Kerberos 5 GSS-API Mechanism in the JDK 8 documentation for information about Java Generic Security Services (Java GSS) for Kerberos 5.