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unblocking a read on System.in

Posted on 2001-07-25
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Last Modified: 2012-05-04
how can i unblock a read on System.in and other InputStreams, from a different thread or whatever?

thanks
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Question by:glow060197
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4 Comments
 
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Sendoh earned 400 total points
ID: 6320500
hi !
u can just create thread 1 the read from System.in...
then create another thread 2 to close the system.in...
after that from thread1 it'll receive an exception...
this might work for ur case anyway...:)

hope it helps.
regards
Sendoh
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Expert Comment

by:stimpyjcat
ID: 6321926
As Sendoh suggests, closing a stream will cause any pending reads to return.

Alternatively, you can change the read loops to only invoke read when there are bytes pending to be read, i.e. available returns non-zero.

boolean done = false;
while (!done) {
     if (in.available()) in.read()
     // sleep or wait
}


Then another thread can simply set done = true in order to stop the reading thread.
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Expert Comment

by:ylyip
ID: 6325581
Just want to point out that there may be a synchronization problem. When 2 threads are working on the same stream object, one read may lock the object and disallow the other to close it.
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Expert Comment

by:stimpyjcat
ID: 6326410
Neither the "read" nor the "close" methods on a stream are synchronized.
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