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many applets accessing a writing servlet ...

Maurice Huellein
Greenhorn

Joined: Jun 29, 2004
Posts: 5
i have a game - applet which includs a highscore. to save the scores permanently theres also a servlet for accessing the server resources. so if theres a new highscore reached the applet sends it to ther servlet, which writes the score in a txt-file on the server.
but im smelling problems if several applets are running at the same time:
for each applet instance a unique servlet connection is created for highscore entry. so only **** would happen if one connection writes to the file, another one reads at the same time and so on.

how can i safely synchronize the data ?

btw: for this project i have no access to a database (which would make many problems obsolete ...)
William Brogden
Author and all-around good cowpoke
Rancher

Joined: Mar 22, 2000
Posts: 12823
    
    5
You could synchronize access to the method that saves the high score and keep a copy of the current high score in memory.
Bill
Maurice Huellein
Greenhorn

Joined: Jun 29, 2004
Posts: 5
i have to clear some points on your suggestion:

as far as i know every applet which starts an urlconnection results in a new instance of the servlet. so i have to care about more than one servlet instance. to have a shared copy of the highscore in memory i would declare it only as static and declare the methods which access the highscore as synchronized...

did i get the point right ?
William Brogden
Author and all-around good cowpoke
Rancher

Joined: Mar 22, 2000
Posts: 12823
    
    5
as far as i know every applet which starts an urlconnection results in a new instance of the servlet.

I think you better get servlet basics firmly in mind before embarking on a project because this is exactly wrong. The Sun tutorial would be a good place to start.
Bill
 
It is sorta covered in the JavaRanch Style Guide.
 
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