A DESCRIPTION OF THE REQUEST :
 At current point we can specify "realm" and "kdc" property for Kerberos authentication using system properties:
"java.security.krb5.realm" and "java.security.krb5.kdc"(or "java.security.krb5.conf").
But there is no possibility to set "realm" and "kdc" for each URLConnection separately.

JUSTIFICATION :
In complex applications, it is impossible to use Kerberos authentication in separate third party plugins(which can authenticate via Kerberos) because we cannot specify different realms and KDC for different connections.
There is the same problem with "java.security.krb5.conf" system property - third party plugin can rewrite this property with its own value. So we should have possibility to define "kdc" and "realm" for each "URLConnection" connection. For example you can add new method to URLConnection:
connection.setRealmAndKdc(String realm, String kdc)