Question about Data class instances

[Efstathios Arethas]

Hello guys!

I am almost done with the project , but i have some thoughts about the Data class , lets take this scenario the user starts a server , then the user starts also a standalone client to work with the same file as the server does , so both server and client work with same db file, i want the server and the standalone client to share the same Data object under the same VM , for the time being they don't share it , in my Data class i use lazy initialization like Map<DatabaseLocation,Data> so from the getInstance( DatabaseLocation) method i expect to get the same Data object , but i don't because the objects i get have different hash codes when i use the same db location string, why this happens? I have tried the singleton pattern also but still different hash codes! I just want to have one Data object per db file , in order the locking mechanism to work for all threads , i must say the server locks the records when requested by the net clients but works independently from the standalone client because they don't share the same Data object. Please advise.

[Roel De Nijs]

From my instructions:

You may assume that at any moment, at most one program is accessing the database file; therefore your locking system only needs to be concerned with multiple concurrent clients of your server.

So your scenario will never occur

[Efstathios Arethas]

Roel De Nijs wrote:From my instructions:

You may assume that at any moment, at most one program is accessing the database file; therefore your locking system only needs to be concerned with multiple concurrent clients of your server.

So your scenario will never occur

Hello Roel
You have right ! I missed this one!
Thank you