Hi Angel,
You should not use the TextLineCodecFactory for reading binary data.
From the example data, I assume your messages have header with a fixed
length of 2 bytes
which should be interpreted as the number of remaining bytes, right ?
I have been working on a tutorial on writing your own
ProtocolDecoder/Encoder, unfortunately I don't have the code right here.
but I tried to reproduce it off the top of my head.
I believe it does what you want, but I have not tested it :-)
The decoder itself is stateless: it stores the conversational state in the
IoSession.
This means you can use the same decoder instance for all your sessions.
import org.apache.mina.filter.codec.CumulativeProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
import org.apache.mina.common.IoSession;
import org.apache.mina.common.ByteBuffer;
public class ByteArrayProtocolDecoder extends CumulativeProtocolDecoder {
private static class DecoderState {
/** whether we have already read the fixed-length header */
boolean headerRead = false;
/** the length of the payload */
int length;
}
/** the header has a fixed length of 2 bytes */
private final static int HEADER_LENGTH = 2;
private final static String DECODER_STATE_KEY =
ByteArrayProtocolDecoder.class.getName() + ".DECODER_STATE";
protected boolean doDecode(IoSession session, ByteBuffer in,
ProtocolDecoderOutput out) throws Exception {
DecoderState state = (DecoderState) session.getAttribute
(DECODER_STATE_KEY);
if (state == null) {
state = new DecoderState();
session.setAttribute(DECODER_STATE_KEY, state);
}
if (!state.headerRead) {
// we have not yet read the header => check if have enough bytes to
read the fixed-length header
if (in.remaining() >= HEADER_LENGTH) {
state.length = in.getShort();
state.headerRead = true;
} else {
// not enough bytes to decode a message, MINA will call us again
when there is more data available
return false;
}
}
if (state.headerRead) {
// we have already read the lengt header, check if all the data is
available
if (in.remaining() >= state.length) {
// ok, message complete
byte[] bytes = new byte[state.length];
in.get(bytes);
// this will cause IoHandler.messageReceived() to be called with a
byte[] as the message
out.write(bytes);
// remove the decoder state to be ready for the next message
session.removeAttribute(DECODER_STATE_KEY);
return true;
}
// not enough bytes available
return false;
}
return false;
}
}
Hope that helps,
Maarten
On 5/11/07, angel figueroa <[EMAIL PROTECTED]> wrote:
Which protocol Filter can be use for receiving Binary Data?
The first two byte is a binary number. I am using TextLineCodecFactory but
i
thing it does not call the messageReceived.
Any Help would be appreciated?
Example
Associated Data - 70 bytes
000: 0044 4953 4F30 3036 3030 3030 3430 3038
.DISO00600004008
008: 3030 3832 3230 3030 3030 3030 3030 3030
0082200000000000
010: 3030 3034 3030 3030 3030 3030 3030 3030
0004000000000000
018: 3030 3035 3130 3230 3237 3433 3030 3030
0005102027430000
020: 3335 3030 3103 35001.
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