NX:[URLyBird]Small case about numeric type

[Richard Jackson]

Hi,all
In my assignment URLyBird,there is a paragraph description following:

Data file Format
The format of data in the database file is as follows:
Start of file
4 byte numeric, magic cookie value. Identifies this as a data file
2 byte numeric, number of fields in each record
Schema description section.
Repeated for each field in a record:
1 byte numeric, length in bytes of field name
n bytes (defined by previous entry), field name
1 byte numeric, field length in bytes
end of repeating block
Data section.
Repeat to end of file:
1 byte flag. 00 implies valid record, 0xFF implies deleted record
Record containing fields in order specified in schema section, no separators between fields, each field fixed length at maximum specified in schema information
End of file
All numeric values are stored in the header information use the formats of the DataInputStream and DataOutputStream classes. All text values, and all fields (which are text only), contain only 8 bit characters, null terminated if less than the maximum length for the field. The character encoding is 8 bit US ASCII.

1 byte flag. 00 implies valid record, 0xFF implies deleted record
According to the BOLD statement:
1)What numeric type and name can I use to assign the flag "valid" or "deleted"?
2)The state said,All numeric values are stored in the header information use the formats of the DataInputStream and DataOutputStream classes.
Must I write a class called Header to store all the data description?And how to invoke the seperated class Header.java?
Thanks in advance,
Richard,
Jul 11,2003

[Ta Ri Ki Sun]

1)What numeric type and name can I use to assign the flag "valid" or "deleted"?

byte will do, as for name, do you mean name of the variable, sorry, I dont think I understand that.

2)The state said,All numeric values are stored in the header information use the formats of the DataInputStream and DataOutputStream classes.
Must I write a class called Header to store all the data description?And how to invoke the seperated class Header.java?

sounds reasonable, but maybe I'm biased to my own implementation, anyhat, my Header instance is a private member of my Data class.

[Tom Lee Jones]

As my idea,the difficulty is to specify some variables and numeric type for the file header,e.g. magic cookie.
And then,you should organize other useful things
and collect information into header information file.
You are free to name them,at the same time,I believe some other professinals will help you.
Good luck!
Regards,
Tom,Jul 2003