Mina Byte数组传输-ByteArrayCodecFactory

public class ByteArrayCodecFactory implements ProtocolCodecFactory {
    private ByteArrayDecoder decoder;
    private ByteArrayEncoder encoder;

    public ByteArrayCodecFactory() {
        encoder = new ByteArrayEncoder();
        decoder = new ByteArrayDecoder();
    }

    @Override
    public ProtocolEncoder getEncoder(IoSession ioSession) throws Exception {
        return encoder;
    }

    @Override
    public ProtocolDecoder getDecoder(IoSession ioSession) throws Exception {
        return decoder;
    }

    //解码
    private class ByteArrayDecoder extends CumulativeProtocolDecoder {


        @Override
        protected boolean doDecode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) throws Exception {
            if (in.remaining() > 6) {//有数据时，读取前8字节判断消息长度

                byte[] sizeBytes = new byte[7];

                in.mark();//标记当前位置，以便reset

                //因为我的前数据包的长度是保存在第6-7字节中，

                in.get(sizeBytes, 0, 7);//读取4字节

                String strHead = bytesToString(sizeBytes,0,4);
                if (!"HOPE".equalsIgnoreCase(strHead)) {
                    in.clear();
                    return true;
                }

                int size = DataTypeUtil.getInt(sizeBytes, 5) + 7;

                in.reset();

                if (size > in.remaining()) {//如果消息内容不够，则重置，相当于不读取size

                    return false;//父类接收新数据，以拼凑成完整数据

                } else {

                    byte[] bytes = new byte[size];

                    in.get(bytes, 0, size);

                    //把字节转换为Java对象的工具类
                    out.write(bytes);

                    if (in.remaining() > 0) {//如果读取内容后还粘了包，就让父类再重读  一次，进行下一次解析

                        return true;

                    }

                }

            }
            return false;//处理成功，让父类进行接收下个包
        }
    }

    //编码
    private class ByteArrayEncoder extends ProtocolEncoderAdapter {
        @Override
        public void encode(IoSession session, Object message,
                           ProtocolEncoderOutput out) {
            byte[] bytes = (byte[]) message;

            IoBuffer buffer = IoBuffer.allocate(256);
            buffer.setAutoExpand(true);
            buffer.put(bytes);
            buffer.flip();
            out.write(buffer);
            out.flush();
            buffer.free();
        }
    }
}