On 3/24/10 1:33 AM, Erinc Arikan wrote:
Sure; but before doing so I am wondering what will happen if the client
sends a message and disconnects while I was intending to send
acknowledgement back, will I receive the same null pointer exception?
no, I don't think so, from the top of my head. However, it has to be
double checked (the session might have been closed, all the pending
message being discarded from the queues...)
Because in the past whenever I had a problem in the response encoder, I used
to see it in the stack trace(like exception at line25 responseencoder.java
etc). I don't feel that message even gets to the encode method in the
encoder.
My encoder is as follows: It simply creates a byte array from getter methods
of the object.
Is it possible you add a try {...} catch (Exception e) {
e.prntStackTrace(); throw e } around your code, so that you have the
opportunity to know where exactly you get this NPE?
Another possibility is that the session has been discarded before the
message is processed completely, so the ProtocolEncoderOutput is null
when you try to inject the encoded message.
You can also call the session.close() with a parameter to tell the
session to close only when there is no more messages to process. (it's a
bit vague in my memory though, and as it's almost 2 am here, i'm too
lazzy to check the code ;)
The problem with the MINA NPE is that it does not inform you about the
real exception you've got.
public void encode(IoSession session, Object message, ProtocolEncoderOutput
out) throws Exception {
int capacity = 1;
//log.warn("encoding the response");
IoBuffer buffer = IoBuffer.allocate(capacity, false);
buffer.setAutoExpand(true);
if(message instanceof ResponseMessage)
{
...
}
else if (message instanceof AckMessage)
{
AckMessage msg = (AckMessage) message;
buffer.put((byte)1);
int tmpMod = msg.getModuloCounter();
byte[] modData = new byte[3];
modData[2] = (byte)(tmpMod& 255);
tmpMod = tmpMod>> 8;
modData[1] = (byte)(tmpMod& 255);
tmpMod = tmpMod>> 8;
modData[0] = (byte)(tmpMod& 255);
buffer.put(modData[0]);
buffer.put(modData[1]);
buffer.put(modData[2]);
buffer.put(msg.getPriority());
buffer.put(msg.getStatus());
buffer.put(msg.getPacketNumber());
buffer.put((byte)msg.getMdtId().length());
buffer.putString(msg.getMdtId(),Charset.forName("ASCII").newEncoder());
buffer.put(msg.getFleetIdLength());
buffer.putString(msg.getFleetId(),Charset.forName("ASCII").newEncoder());
buffer.put(msg.getCmtTokenLength());
buffer.putString(msg.getCmtToken(),Charset.forName("ASCII").newEncoder());
buffer.putChar((char) 0);
buffer.put((byte)4);
buffer.flip();
}
try
{
byte[] byteArray = TrimArray(buffer.array());
int tmpCrc = CRCCalculation(byteArray);
byte[] crcData = new byte[2];
crcData[1] = (byte)(tmpCrc& 255);
tmpCrc = tmpCrc>> 8;
crcData[0] = (byte)(tmpCrc& 255);
byteArray[byteArray.length-3] = crcData[0];
byteArray[byteArray.length-2] = crcData[1];
buffer = IoBuffer.wrap(Stuff(byteArray));
out.write(buffer);
}
catch(Exception e)
{
log.error(e.getMessage());
}
}
On Tue, Mar 23, 2010 at 7:30 PM, Emmanuel Lecharny<[email protected]>wrote:
On 3/24/10 12:08 AM, Erinc Arikan wrote:
I am using MINA 2.0.0.RC1, I built my own protocol codec filter to deal
with
messages. All of my tests went fine in test environments and I went live
recently. I am processing almost a message every second.
The issue that I experienced in the production environment is random null
pointer exceptions. I suspect that they are happening when I try to write
back an ack message to the session in my custom message handler. Following
is the exception trace:
You most certainly have an issue in your encoder. Now, I agree that it's
difficult to tell exactly what's going wrong with this stack trace...
Is it possible to see the code of your encoder ?
--
Regards,
Cordialement,
Emmanuel Lécharny
www.nextury.com
--
Regards,
Cordialement,
Emmanuel Lécharny
www.nextury.com
