@Override
public BasicCoapResponse createResponse(
CoapMessage request, CoapResponseCode responseCode, CoapMediaType contentType) {
BasicCoapResponse response;
if (request.getPacketType() == CoapPacketType.CON) {
response =
new BasicCoapResponse(
CoapPacketType.ACK, responseCode, request.getMessageID(), request.getToken());
} else if (request.getPacketType() == CoapPacketType.NON) {
response =
new BasicCoapResponse(
CoapPacketType.NON, responseCode, request.getMessageID(), request.getToken());
} else {
throw new IllegalStateException(
"Create Response failed, Request is neither a CON nor a NON packet");
}
if (contentType != null && contentType != CoapMediaType.UNKNOWN) {
response.setContentType(contentType);
}
response.setChannel(this);
return response;
}
public void handleMessage(CoapMessage message) {
if (message.isRequest()) {
/* this is a client channel, no requests allowed */
message
.getChannel()
.sendMessage(new CoapEmptyMessage(CoapPacketType.RST, message.getMessageID()));
return;
}
if (message.isEmpty() && message.getPacketType() == CoapPacketType.ACK) {
/* this is the ACK of a separate response */
// TODO: implement a handler or listener, that informs a client when a sep. resp. ack was
// received
return;
}
if (message.getPacketType() == CoapPacketType.CON) {
/* this is a separate response */
/* send ACK */
this.sendMessage(new CoapEmptyMessage(CoapPacketType.ACK, message.getMessageID()));
}
/* check for blockwise transfer */
CoapBlockOption block2 = message.getBlock2();
if (blockContext == null && block2 != null) {
/* initiate blockwise transfer */
blockContext = new ClientBlockContext(block2, maxReceiveBlocksize);
blockContext.setFirstRequest(lastRequest);
blockContext.setFirstResponse((CoapResponse) message);
}
if (blockContext != null) {
/*blocking option*/
if (!blockContext.addBlock(message, block2)) {
/*this was not a correct block*/
/* TODO: implement either a RST or ignore this packet */
}
if (!blockContext.isFinished()) {
/* TODO: implement a counter to avoid an infinity req/resp loop:
* if the same block is received more than x times -> rst the connection
* implement maxPayloadSize to avoid an infinity payload */
CoapBlockOption newBlock = blockContext.getNextBlock();
if (lastRequest == null) {
/*TODO: this should never happen*/
System.out.println("ERROR: client channel: lastRequest == null");
} else {
/* create a new request for the next block */
BasicCoapRequest request =
new BasicCoapRequest(
lastRequest.getPacketType(),
lastRequest.getRequestCode(),
channelManager.getNewMessageID());
request.copyHeaderOptions((BasicCoapRequest) blockContext.getFirstRequest());
request.setBlock2(newBlock);
sendMessage(request);
}
/* TODO: implement handler, inform the client that a block (but not the complete message) was received*/
return;
}
/* blockwise transfer finished */
message.setPayload(blockContext.getPayload());
/* TODO: give the payload separately and leave the original message as they is*/
}
/* normal or separate response */
client.onResponse(this, (BasicCoapResponse) message);
}