BigIntegerDecoder Class — netty Architecture

Source Code

example/src/main/java/io/netty/example/factorial/BigIntegerDecoder.java lines 32–63

public class BigIntegerDecoder extends ByteToMessageDecoder {

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
        // Wait until the length prefix is available.
        if (in.readableBytes() < 5) {
            return;
        }

        in.markReaderIndex();

        // Check the magic number.
        int magicNumber = in.readUnsignedByte();
        if (magicNumber != 'F') {
            in.resetReaderIndex();
            throw new CorruptedFrameException("Invalid magic number: " + magicNumber);
        }

        // Wait until the whole data is available.
        int dataLength = in.readInt();
        if (in.readableBytes() < dataLength) {
            in.resetReaderIndex();
            return;
        }

        // Convert the received data into a new BigInteger.
        byte[] decoded = new byte[dataLength];
        in.readBytes(decoded);

        out.add(new BigInteger(decoded));
    }
}