Hi,
My requirement is to write a server that is capable of holding long
conversations with the client based on socket programming for Java. I'm
using ServerSocket to create TCP sockets. The problem I am running into is
that I am not able to do [read, write, read] sequence of operations reliably
on my socket. Here is my [read, write, read] code:
1: int numBytesRead = socket.getInputStream().read(buffer);
2: System.out.println(numBytesRead);
3: socket.getOutputStream().write(new byte[] { 'a', 'b', 'c' });
4: socket.getOutputStream().flush();
5: numBytesRead = socket.getInputStream().read(buffer);
6: System.out.println(numBytesRead);
On line 5 in this code, the read operation is NOT blocking and will return
-1. After some testing, I concluded that after flushing output [line 4],
the input stream will not block anymore. However, if I comment out line 4,
the read operation will block again, and will continue to block on
subsequent attempts for read before any output flush. What I want is to
implement persistent connections which enable me to read client's input,
respond, and repeat without closing the socket. I believe this possible
with Tomcat but I can't figure out how Http11Processor implements it.
Can anyone give me any ideas as to WHY this is the behaviour to be expected
in my code? Why is that a output flush causes my input stream to behave
unexpectedly? And how do I correctly implement read, write, read for support
persistent connections? Surely this can be done right? I only hope so.
--
Hung Tang
