question: public static String generateClientIdWithTimestamp ( final String clientId , final ProtocolVersionEnum protocol ) { final int addedLength = CLIENT_ID_TIMESTAMP_FORMAT . length ( ) + CLIENT_ID_TIMESTAMP_DELIMITER . length ( ) ; final int index = clientId . lastIndexOf ( CLIENT_ID_TIMESTAMP_DELIMITER ) ; String newClientId = clientId ; if ( index >= 0 && ( index + addedLength == newClientId . length ( ) ) ) { newClientId = newClientId . substring ( 0 , index ) ; } if ( limitClientId ( protocol ) && newClientId . length ( ) + addedLength > MAX_CLIENT_LENGTH_FOR_3_1 ) { newClientId = newClientId . substring ( 0 , MAX_CLIENT_LENGTH_FOR_3_1 - addedLength ) ; } newClientId = newClientId + CLIENT_ID_TIMESTAMP_DELIMITER + CLIENT_ID_SDF . format ( new Date ( ) ) ; return newClientId ; }
target:  Generate client ID with timestamp.