Checking for a deleted record

[Robert Benson]

Hi,
I'm working on the delete room functionality:

When a room is deleted, it is set to "1" or stored as 31 on file.

When I read back the file all the deleted rooms contain "31" in the expected position. When this is converted back the deleted field is 1 except for the last record which is -1. The last record fails my test to check if a room is deleted. However, if I check for the absolute value of deleted, it works fine. It works, but probably for the wrong reasons. I just want to check this is ok and not some dodgy code that will score badly.

I know its the last record, but I'm not reading the whole of the last record only a small portion of it so I wouldn't be expecting a -1 just yet.

This is a portion of my code:

   RecordFieldReader readRecord = new RecordFieldReader();
        String recordDeleted = readRecord.read(RECORD_DELETED_IND_SIZE);   //RECORD_DELETED_IND_SIZE = 1
        byte[] byteArray = recordDeleted.getBytes("UTF-8");
        int deleted = database.read(byteArray);

        log.info("record number " + recordNumber + " , deleted? = " + deleted);
        if ( deleted == 1){
            log.info("Record deleted: record number = " + recordNumber);
            throw new RecordNotFoundException("Room record deleted, " +
                                               "record number = " + recordNumber);
        }

        //if ( Math.abs(deleted) == 1){
        //    log.info("Record deleted: record number = " + recordNumber);
        //    throw new RecordNotFoundException("Room record deleted, " +
        //                                       "record number = " + recordNumber);
        //
        //}
  

regards, Robert.

[Roel De Nijs]

Hi Robert,

The length of the deleted flag in my assignment was also 1 byte. I use 0 for a valid record and 1 for a deleted record.

To read the deleted flag I use:

byte deleted = database.readByte();

To write the deleted flag I use:

byte deleted = ...;
database.writeByte(deleted);

Never experienced a negative number for the deleted flag.

Kind regards,
Roel