How to use checksum in a DatagramPacket in java?

[phpuser123]

For instance I have the following codes:

public void clients(){
 
     try
     {           address =InetAddress.getByName("localhost");
                 byte[] SBM_client_array_receive=new byte[256];
                 byte[] SBM_client_array_send;
                 String SBM_login="SBM login "+"username"+""+"passowrd";
                 SBM_client_array_send=SBM_login.getBytes();
                 System.out.println("Sending .."+SBM_login);
                 SBM_client_socket=new DatagramSocket();
                 SBM_packet_send=new DatagramPacket(SBM_client_array_send,SBM_client_array_send.length,address,8000);
                 SBM_client_socket.send(SBM_packet_send);
 
                 SBM_client_array_receive=new byte[256];
                 SBM_packet_receive = new DatagramPacket(SBM_client_array_receive, SBM_client_array_receive.length);
                 SBM_client_socket.receive(SBM_packet_receive);
 
 
 
 
     }
  catch(IOException e)
             {
        System.err.println(e.getMessage());
 
 
                          // TODO add your handling code here:
              }
 
}
 

If I have the following codes,how can I modify it such that I can include a checksum in the datagrampacket?

Are there any java methods to do that ?