A questions about UrlyBird

[Gerenne Vives]

Hello , my assigment is UrlyBird , and I have some questions:

1-Is correct to use a sockets instead of rmi???

2-The interface may be in a package called propeties.db instead of properties.db ??

3-I don,t understand :"1 byte deleted falg.0 implies valid record" ,I must introduce to end of each registry flag indicative in the file of the data base as if one was about a field but the registry?

4-What are the means the magic cokie and lockcokie?

5-is obligatory to always pass a way flag or it is possible to be omitted?

6-The distribution that I have I throw is the following one :

suncertify.db
-Class exceptions.
-Locking mechanism
-Class Data ( implements interfaz )
suncertify.DataBase
-Interfaz
-DatabaseLocation ( return a class that bd is located, the local or the remote)
suncertify.Client
-Ini Class ( call a DatabaseLocation , and a class gui)
-Gui (graphic interface)
-DataBase ( implement interfaz , mode local)
-Conexion ( in case that the connection is in connected mode)

This is my questions , thanks in advance and I feel that my ingles is so bad .

[Gerenne Vives]

is correct the distribuition the package??

[Paul Bourdeaux]

Hi Irene,

I have the B&S assignment, but I believe much of the structure of the assignment is similar. I will try and answer the questions that I can.

1-Is correct to use a sockets instead of rmi???

You can use either sockets or rmi, which ever you prefer.

2-The interface may be in a package called propeties.db instead of properties.db ??

I think the interface is supposed to be in the suncertify.db package, along with your implementation of the Data.java class. That is how it is with my assignment at least.

3-I don,t understand :"1 byte deleted falg.0 implies valid record" ,I must introduce to end of each registry flag indicative in the file of the data base as if one was about a field but the registry?

There is a flag in each of the records to identify whether it is a valid record or a record that has been deleted. This allows you to reuse deleted record space when creating a new record. It is also a much simpler delete approach than actually removing the record from the file.

4-What are the means the magic cokie and lockcokie?

The magic cookie identifes the file as a data file. Check out this link for more on that topic. The lock cookie is a unique number that is passed back to the client when it locks a record. Only the client that has the correct lock cookie can unlock, delete, or update a record.

5-is obligatory to always pass a way flag or it is possible to be omitted?

I am sorry, I am not sure what you mean by this question.

6-The distribution that I have I throw is the following one : ...

My suggestino would be to combine the db and DataBase packages. In my assignment, I have the following packages:
suncertify.db - Contains all code relating to the database
suncertify.remote - Contains networking code
sunceritify.gui - Contains the user interfaces as well as the application runner.

I hope this helped. Good luck.

[Gerenne Vives]

thanks for your help !!!