OP320C/src/com/mes/netty/XDecoder.java

package com.mes.netty;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

public class XDecoder extends ByteToMessageDecoder {

    public static final Logger log =  LoggerFactory.getLogger(XDecoder.class);
    static final int PACKET_SIZE = 46; // 最短包长度
    static final int PACKET_MAX_SIZE = 1000; // 最长包长度

    // 用来临时保留没有处理过的请求报文
    ByteBuf tempMsg = Unpooled.buffer();

    /**
     * @param ctx
     * @param in 请求的数据
     * @param out 将粘在一起的报文拆分后的结果保留起来
     * @throws Exception
     */
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        log.info(Thread.currentThread() + "收到了一次数据包，长度是：" + in.readableBytes());
        String content = hexStringToAscii(ByteBufUtil.hexDump(in));
        log.info("接收包内容：" + hexStringToAscii(ByteBufUtil.hexDump(in)));

        // 合并报文
        ByteBuf message = null;
        int tmpMsgSize = tempMsg.readableBytes();
        // 如果暂存有上一次余下的请求报文，则合并
        if (tmpMsgSize > 0) {
            message = Unpooled.buffer();
            message.writeBytes(tempMsg);
            message.writeBytes(in);
            log.info("合并：上一数据包余下的长度为：" + tmpMsgSize + ",合并后长度为:" + message.readableBytes());
            log.info("合并后包内容：" + hexStringToAscii(ByteBufUtil.hexDump(message)));
        } else {
            message = in;
        }

//        log.info(Thread.currentThread() + "收到了一次数据包，长度是：" + message.readableBytes());
        int size = 0;
        String split = "bbbbfffffARW";

        while (true){
            size = message.readableBytes();
            if(size >= PACKET_SIZE){
                String retType = "NG:";
                int qcsize = 0;
                String str = hexStringToAscii(ByteBufUtil.hexDump(message));
                String[] lists = str.split(split);

                if(lists.length == 1 && size > PACKET_MAX_SIZE){ // 大于最大包长度
                    byte[] request = new byte[size - PACKET_MAX_SIZE];
                    // 每次从总的消息中读取n个字节的数据
                    message.readBytes(request);
                    // 将拆分后的结果放入out列表中，交由后面的业务逻辑去处理
                    out.add(retType+hexStringToAscii(ByteBufUtil.hexDump(Unpooled.copiedBuffer(request))));
                    break;
                }

                if(lists[0].length() > 0){
                    byte[] request = new byte[lists[0].length()];
                    // 每次从总的消息中读取n个字节的数据
                    message.readBytes(request);
                    // 将拆分后的结果放入out列表中，交由后面的业务逻辑去处理
                    out.add(retType+hexStringToAscii(ByteBufUtil.hexDump(Unpooled.copiedBuffer(request))));
                }else{
                    if(lists.length > 1){
                        String ss = lists[1];
                        if(ss.length() <= 4){
                            qcsize += ss.length();
                        }else{
                            String msgType = ProtocolParam.getMsgType(split+ss);
                            if(!MesMsgUtils.isMsgTypeOk(msgType)){
                                qcsize += split.length() + ss.length();
                            }else{
                                Integer ppsize = checkResultSize(ss,msgType,split);
                                if(ppsize > 0){
                                    qcsize = ppsize;
                                    retType = "OK:";
                                }else{
                                    qcsize += split.length() + ss.length();
                                }
                            }
                        }
                    }
                }


                if(qcsize > 0){
                    byte[] request = new byte[qcsize];
                    // 每次从总的消息中读取n个字节的数据
                    message.readBytes(request);
                    // 将拆分后的结果放入out列表中，交由后面的业务逻辑去处理
                    out.add(retType+hexStringToAscii(ByteBufUtil.hexDump(Unpooled.copiedBuffer(request))));
                }
            }else{
                break;
            }
        }

        // 多余的报文存起来
        // 第一个报文： i+  暂存
        // 第二个报文： 1 与第一次
        size = message.readableBytes();
        if (size != 0) {
            log.info("多余的数据长度：" + size);
            // 剩下来的数据放到tempMsg暂存
            tempMsg.clear();
            tempMsg.writeBytes(message.readBytes(size));
        }
    }

    private Integer checkResultSize(String str, String msg_type, String split){
        String oldstr = str;
        str = split+str;
        int tpsize = 0;
        switch(msg_type) {
            case "SYNR": // 同步
                if(str.length() >= MesMsgUtils.SYNR_LEN){
                    tpsize = MesMsgUtils.SYNR_LEN;
                }
                break;
            case "AXTW": // 心跳
                if(str.length() >= MesMsgUtils.AXTW_LEN){
                    tpsize = MesMsgUtils.AXTW_LEN;
                }
                break;
            case "ACLW": // 重连
                if(str.length() >= MesMsgUtils.ACLW_LEN){
                    tpsize = MesMsgUtils.ACLW_LEN;
                }
                break;
            case "MCJW":
            case "AQDW":
            case "MBDW":
            case "MJBW":
            case "MQDW":
            case "MKSW":
            case "MSBW":
            case "MCSW":
            case "AQRW":
            default: // 默认新报文
                if(str.length() >= ProtocolParam.fixedLength){ // 大于固定长度
                    tpsize = ProtocolParam.fixedLength;
                }
                break;
        }

        return tpsize;
    }

    // 16字符串转Ascii
    private String hexStringToAscii(String hexString) {
        StringBuilder sbuilder = new StringBuilder();
        for (int i = 0; i < hexString.length(); i += 2) {
            String hexByte = hexString.substring(i, i + 2);
            int byteValue = Integer.parseInt(hexByte, 16);
            char c = (char) byteValue;
            sbuilder.append(c);
        }
        return sbuilder.toString();
    }
}