Configuring to use Kerberos

testKerberosAL {
com.ibm.security.auth.KerberosLoginModule required
debug=true;
};........login configuration file

...
LoginContext lc = new LoginContext("testKerberosAL");
lc.login();
Subject whoami = lc.getSubject();
Subject.doAs(lc.getSubject(), someActionInstance);
...
..........code in exploiting application