DatagramDnsResponseDecoder Class — netty Architecture

Source Code

codec-dns/src/main/java/io/netty/handler/codec/dns/DatagramDnsResponseDecoder.java lines 30–68

@ChannelHandler.Sharable
public class DatagramDnsResponseDecoder extends MessageToMessageDecoder<DatagramPacket> {

    private final DnsResponseDecoder<InetSocketAddress> responseDecoder;

    /**
     * Creates a new decoder with {@linkplain DnsRecordDecoder#DEFAULT the default record decoder}.
     */
    public DatagramDnsResponseDecoder() {
        this(DnsRecordDecoder.DEFAULT);
    }

    /**
     * Creates a new decoder with the specified {@code recordDecoder}.
     */
    public DatagramDnsResponseDecoder(DnsRecordDecoder recordDecoder) {
        super(DatagramPacket.class);
        this.responseDecoder = new DnsResponseDecoder<InetSocketAddress>(recordDecoder) {
            @Override
            protected DnsResponse newResponse(InetSocketAddress sender, InetSocketAddress recipient,
                                              int id, DnsOpCode opCode, DnsResponseCode responseCode) {
                return new DatagramDnsResponse(sender, recipient, id, opCode, responseCode);
            }
        };
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, DatagramPacket packet, List<Object> out) throws Exception {
        try {
            out.add(decodeResponse(ctx, packet));
        } catch (IndexOutOfBoundsException e) {
            throw new CorruptedFrameException("Unable to decode response", e);
        }
    }

    protected DnsResponse decodeResponse(ChannelHandlerContext ctx, DatagramPacket packet) throws Exception {
        return responseDecoder.decode(packet.sender(), packet.recipient(), packet.content());
    }
}