Java external Process error stream readLine() blocks intermittently -


i shelling external windows program updates progress repeatedly pushing new lines error stream.

the command prompt looks when it's running:

10% done 10% done 11% done

and forth.

i'm having success capturing in java application thusly:

process process = runtime.getruntime().exec("my little command"); bufferedreader stdinput = new bufferedreader(new inputstreamreader(process.getinputstream())); bufferedreader stderror = new bufferedreader(new inputstreamreader(process.geterrorstream())); string s; while((s = stderror.readline())!=null) {     system.out.println(s);                   }

unfortunately, may have guessed, there's bit of problem. stderror.readline() blocks until there +- 4000 bytes in error stream, , prints each line out in quick session, before hangs again.

i've tried changing bufferedreader buffer size, , using stderror.read(char [] cbuf, int off, int len)with small length, no avail.

how fix hanging issue?

thanks in advance :)

the stderror.readline() blocks until there +- 4000 bytes in error stream

no doesn't. returns there line read.

what happening source process buffering output, evidently 4096-byte chunks. there's nothing can @ java end.


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