Spring authorization server stores KerberosServiceRequestToken object in the database.
While storing the object serialization takes place and serialized object gets stored in table.
But "KerberosTicketValidation ticketValidation" field is marked as transient, so it is not serialized or stored.
While retrieving KerberosServiceRequestToken from database, de-serialization takes place and it goes to create KerberosServiceRequestToken object with deserialized fields by MixIn class.
However, while creating new object of KerberosServiceRequestToken requires "KerberosTicketValidation ticketValidation" field in the constructor. But as deserialized class doesn't contain transient field, constructor call gives NullPointerException because it uses ticketValidation subject and username to create JassSubjectHolder.
Spring authorization server stores KerberosServiceRequestToken object in the database.
While storing the object serialization takes place and serialized object gets stored in table.
But "KerberosTicketValidation ticketValidation" field is marked as transient, so it is not serialized or stored.
While retrieving KerberosServiceRequestToken from database, de-serialization takes place and it goes to create KerberosServiceRequestToken object with deserialized fields by MixIn class.
However, while creating new object of KerberosServiceRequestToken requires "KerberosTicketValidation ticketValidation" field in the constructor. But as deserialized class doesn't contain transient field, constructor call gives NullPointerException because it uses ticketValidation subject and username to create JassSubjectHolder.