Signifiance of setSoTimeout() ?

Hello there,
The documentation of Socket.setSoTimeout states:
+"...With this option set to a non-zero timeout, a read() call on the InputStream associated with this Socket will block for only this amount of time. If the timeout expires, a java.net.SocketTimeoutException is raised..."+. Simple enough, but I dont understand it's significance. Let me explain, I did a small test using the following code:
public static void main( String[] args )
   Socket s = new Socket("72.5.124.111", 80 );
   s.setSoTimeout(9000);//9 seconds
   InputStream is = s.getInputStream();
   while( is.read(buffer) != -1 )
     System.out.println(amountRead);
}As you can see, I am waiting for a response from an HTTP server, even though I have not sent any request to it. Clearly this code is stupid and as expected, I get a SocketTimeoutException after 9 seconds.
However I remove the s.setSoTimeout() line... I get an error from the native environment exactly after 60 seconds (I counted using a stop watch!).
Now we know that Socket works on TCP/IP, and therefore retries and timeouts are handled by the protocol itself. So my question is... why would anyone need setSoTimeout()? Is it a mistake to set the Timeout less than TCP's default timeout (in my case it seems it was 60 seconds)?
Edited by: GizmoC on Apr 28, 2008 2:20 AM

Maybe I don't quite get your question, but this should be rather obvious. If you are trying to make a request to a remote server and that server is unavailable, you usually won't want to wait 60 seconds to know that. Imagine you are writing an FTP client, the user enters a server name and clicks 'connect'. Now, would you want him to wait for 60 seconds before telling him that the server could not be connected to?

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How to use setSoTimeOut() with socket ??

HI All!
I eagerly need to know how to use setSoTimeOut() with socket (on server side).
Actually the scenario is that My Server accepts connection and waits for connected client to send data to it. I WANT TO KEEP, IF CLIENT DOENS'T SENDS ANY DATA TO SERVER WITHIN 5 min. THEN SERVER MUST CLOSE THE CONNECTION, BUT IF SERVER RECEIVES STILL A BYTE FROM THE CLIENT WITHIN 5 mins., THE SERVER MUST RESET CHECKING TIME OUT FOR NEXT 5 MINUTES.
How can i do that??
Any help with example will be appreciated!!
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I have noticed that if a timeout happens after I have flushed some strings with a BufferedWriter.write, but before I have generated a string with EOL, the BufferedReader.readLine first generates a SocketTimeoutException, and then readLine-method returns the flushed strings even though none of them had a "\n", "\r" or "\r\n".
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Socket.setSoTimeOut() i dont get it

setSoTimeout
public void setSoTimeout(int timeout)
throws SocketExceptionEnable/disable SO_TIMEOUT with the specified timeout, in milliseconds. With this option set to a non-zero timeout, a read() call on the InputStream associated with this Socket will block for only this amount of time. If the timeout expires, a java.net.SocketTimeoutException is raised, though the Socket is still valid. The option must be enabled prior to entering the blocking operation to have effect. The timeout must be > 0. A timeout of zero is interpreted as an infinite timeout.
i dont get what it means when it says block? stop? And when it says it must be vailid prior to entering the block operation where abouts is that?
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Some Socket methods are designed to read a known number of bytes from an input stream. If those methods read less than the specified number of bytes, they will "block", which means that Socket is incapable of performing any other task until the read method completes. This can tie up system resources by keeping connections open, and might not be something desired. To avoid this, you would set the Socket's timeout value, and after the specified interval, if the Socket is still "blocked", it will timeout. When it times out, it throws an exception, but does not close the Socket or perform any Socket-related shutdown routines; it has not been "stopped". In order to shut down the Socket, you would have to write code to catch the appropriate exception, and explicitly close the Socket in that catch block. The explanation of the Socket's behavior is intended to let you know that the timeout process that happens when you set a timeout value greater than 0 is not designed to perform any resource deallocation or Socket close actions - that responsibility is left up to the programmer to handle or delegate as they see fit.
So basically, a Socket, when attempting to read from an input stream, will not be able to do anything else until that read completes - it "blocks" waiting for the read to complete. If the read does not complete, a method is needed to free up resources that may be associated with that Socket after a certain amount of time has passed (maybe the code is being run in an environment where system thread or connectivity resources are at a premium). By setting a timeout value on a Socket you can achieve this goal, but the responsibility for stopping or closing the Socket so that the appropriate resources are released lies with the programmer using the Socket.
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When I tried to perform reading in blocking mode with using NIO's SocketChannel.read() method with a desired timeout, the SocketChannel.socket().setSoTimeout() method that was called before SocketChannel().read() funtion, seemed not to work properly. The read() method blocked the thread for infinite time even if I set the timeout to any non-zero value (zero means according the manual infinite timeout).
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Signifiance of setSoTimeout() ?

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