自定义编码解码器

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.util.List;

public class MyByteToLongDecoder extends ByteToMessageDecoder {

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        System.out.println("MyByteToLongDecoder:" + in.readableBytes());
        if (in.readableBytes() >= 8) {
            out.add(in.readLong());
        }
    }
}

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;

public class MyLongToByteEncoder extends MessageToByteEncoder<Long> {
    @Override
    protected void encode(ChannelHandlerContext ctx, Long msg, ByteBuf out) throws Exception {
        System.out.println("MyLongToByteEncoder:" + msg);
        out.writeLong(msg);
    }
}

ReplayingDecoder

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ReplayingDecoder;

import java.util.List;

public class MyByteToLongDecoder2 extends ReplayingDecoder<Void> {
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        System.out.println("MyByteToLongDecoder2:" + in.readableBytes());
        out.add(in.readLong());
    }
}

MessageToMessageDecoder

import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageDecoder;

import java.util.List;

public class MyLongToStringDecoder extends MessageToMessageDecoder<Long> {

    @Override
    protected void decode(ChannelHandlerContext ctx, Long msg, List<Object> out) throws Exception {
        System.out.println("MyLongToStringDecoder:" + msg);
        out.add(String.valueOf(msg));
    }
}