array of bytes into a ByteBuf and vice versa. io.netty.handler.codec.compression Encoder and decoder which compresses and decompresses ByteBuf s in a compression format such as zlib and gzip . io.netty.handler.codec.http Encoder, decoder and their related message types for HTTP. io.netty.handler.codec.http.websocketx Encoder, decoder, handshakers and their related message types for Web Socket