Unable to send data over TCP from java socket to .net tcp server

Question

i am trying to get an android app to send tcp data to a server on my network. The server was written in c#.

When i use the code below to transmit data, the server only receives a whole series of \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0.

Does anyone know why?

Socket socket = new Socket(host, port);
PrintWriter pw = new PrintWriter(socket.getOutputStream(), true);
pw.print("test");
socket.close();

One thought is to check if the encoding of what is being sent matches what the server expects. — fhj
– fhj, Commented Nov 2, 2010 at 5:47

bcat · Accepted Answer · 2010-11-02 05:45:19Z

2

I'm not sure if this has anything to do with it, but you might want to try manually flushing the PrintWriter. You did pass true to its constructor to request autoflushing, but I believe this only occurs when you print a newline character, which your sample code doesn't do.

answered Nov 2, 2010 at 5:45

bcat

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2 Comments

st0le Over a year ago

shouldn't the close flush before closing?

bcat Over a year ago

Yes, but that will only flush the socket's buffers. The PrintWriter class maintains buffers of its own which must be flushed before the socket is closed to ensure that all data is delivered properly.

user207421 · Accepted Answer · 2010-11-02 08:46:00Z

1

Close the PrintWriter, not the Socket.

answered Nov 2, 2010 at 8:46

user207421

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Comments

Jim · Accepted Answer · 2010-11-02 05:46:40Z

0

you may want to try println("test"). In java you need to flush the line, so that may be the cause of your issues.

answered Nov 2, 2010 at 5:46

Jim

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