Server side does not detect network failure

Hi folks,
I coded a simple chat program. When a client connects to the multi-thread server, server shows newly connected client's IP address. Now, if the connection between client and server is down, client detects and terminates itself but server does not. The server still shows that client as connected. when I traced the server side, I found out that server was waiting at the readObject (client object input stream) line but it didn't throw any IOException. I tried to send some message to all connected client at every 20 seconds, so I expected to catch IOException when the server did not reach the client. Unfortunately, it didn't work. That is my question how can server side detect network failure?
Thanks for help.
Regards
Bulent

That is how TCP works (noting that it has nothing to do with java.)
Your solution is one of the following or some combination...
- If the server does not receive something every X time period then it disconnects.
- If the server has not received something after X time period it sends a keep alive message to the client. If the client does not respond (or the message fails) then the server disconnects.

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Server side does not detect network failure

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