Change tomcat filter from NTLMv1 to NTLMv2 or Kerberos

We have an old Application running on Tomcat 5.5 that uses a NTLMv1 filter to verify the users.
We need to upgrade the JAVA filter to use NTLMv2 or Kerberos.

The NTLM code from the filter is included below:

//NLTM Module here
                  String auth = request.getHeader("Authorization");
                  
                  if (auth == null)
                  {
                    response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
                    response.setHeader("WWW-Authenticate", "NTLM");
                    //response.flushBuffer();
                    LogManager.debug("First Authentication check failed",AuthenticationFilter.class);
                    return;
                  }
                  if (auth.startsWith("NTLM"))
                  {
                    byte[] msg = new sun.misc.BASE64Decoder().decodeBuffer(auth.substring(5));
                    LogManager.debug("NTLM response="+new String(msg, Charset.forName("ISO-8859-1")),AuthenticationFilter.class);
                    int off = 0, length, offset;
                    if (msg[8] == 1)
                    {
                        LogManager.debug("Second Authentication check failed",AuthenticationFilter.class);
                      byte z = 0;
                      byte[] msg1 = {(byte)'N', (byte)'T', (byte)'L', (byte)'M', (byte)'S', (byte)'S', (byte)'P', z,(byte)2, z, z, z, z, z, z, z,(byte)40, z, z, z, (byte)1, (byte)130, z, z,z, (byte)2, (byte)2, (byte)2, z, z, z, z, z, z, z, z, z, z, z, z};
                      response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
                      response.setHeader("WWW-Authenticate", "NTLM " + new sun.misc.BASE64Encoder().encodeBuffer(msg1).trim());
                      //response.flushBuffer();
                      //response.sendError(response.SC_UNAUTHORIZED);
                      LogManager.debug("Sending unauthorized and flushing buffer",AuthenticationFilter.class);
                      return;
                    }
                    else if (msg[8] == 3)
                    {
                        LogManager.debug("Third Authentication check passed",AuthenticationFilter.class);
                      off = 30;
            
                      //get details
                      length = msg[off+17]*256 + msg[off+16];
                      offset = msg[off+19]*256 + msg[off+18];
                      remoteHost = cleanString(new String(msg, offset, length));
            
                      length = msg[off+1]*256 + msg[off];
                      offset = msg[off+3]*256 + msg[off+2];
                      domain = cleanString(new String(msg, offset, length));
            
                      length = msg[off+9]*256 + msg[off+8];
                      offset = msg[off+11]*256 + msg[off+10];
                      username = cleanString(new String(msg, offset, length));
                        
                        LogManager.info(new StringBuilder("User [").append(username).append("] NTLM Authenticated...domain[").append(domain).append("] RemoteHost: [").append(remoteHost).append("]").toString(),AuthenticationFilter.class);
                    
                  //Userid check here