TcpDnsResponseEncoder Class — netty Architecture

Source Code

codec-dns/src/main/java/io/netty/handler/codec/dns/TcpDnsResponseEncoder.java lines 26–55

@ChannelHandler.Sharable
public final class TcpDnsResponseEncoder extends MessageToMessageEncoder<DnsResponse> {
    private final DnsRecordEncoder encoder;

    /**
     * Creates a new encoder with {@linkplain DnsRecordEncoder#DEFAULT the default record encoder}.
     */
    public TcpDnsResponseEncoder() {
        this(DnsRecordEncoder.DEFAULT);
    }

    /**
     * Creates a new encoder with the specified {@code encoder}.
     */
    public TcpDnsResponseEncoder(DnsRecordEncoder encoder) {
        super(DnsResponse.class);
        this.encoder = ObjectUtil.checkNotNull(encoder, "encoder");
    }

    @Override
    protected void encode(ChannelHandlerContext ctx, DnsResponse response, List<Object> out) throws Exception {
        ByteBuf buf = ctx.alloc().ioBuffer(1024);

        buf.writerIndex(buf.writerIndex() + 2);
        DnsMessageUtil.encodeDnsResponse(encoder, response, buf);
        buf.setShort(0, buf.readableBytes() - 2);

        out.add(buf);
    }
}