public static String generateConnectionCacheKey(String host,int port){
  return (host == null || host.isEmpty()) ? null : host + HOST_PORT_SEPARATOR + port;
}

public static String generateConnectionCacheKey ( String host , int port ) { return ( host == null || host . isEmpty ( ) ) ? null : host + HOST_PORT_SEPARATOR + port ; }
generate the key that is used to cache the connection .
