@Override
protected Object decode(
final ChannelHandlerContext ctx, final Channel channel, final ChannelBuffer buffer)
throws Exception {
while (buffer.readable()) {
byte c = buffer.readByte();
// check if last character read was DLE
if (foundDLE) {
foundDLE = false;
if (c == DleStxEtxConstants.STX && !foundPacket) {
foundPacket = true;
} else if (c == DleStxEtxConstants.ETX && foundPacket) {
ChannelBuffer packetRead = packet;
resetDecodingState();
return packetRead;
} else if (c == DleStxEtxConstants.DLE && foundPacket) {
// Stuffed DLE found
packet.writeByte(DleStxEtxConstants.DLE);
} else {
if (log.isWarnEnabled()) {
log.warn(
"Incomplete packet received: {}",
StringUtils.toHexString(
packet.array(), packet.readerIndex(), packet.readableBytes()));
}
resetDecodingState();
}
} else {
if (c == DleStxEtxConstants.DLE) {
// log.trace("Plain DLE received");
foundDLE = true;
} else if (foundPacket) {
packet.writeByte(c);
}
}
}
// decoding is not yet complete, we'll need more bytes until we find DLE
// ETX
return null;
}
