JAVA使用socket与PLC通信

package com.hcs.base;

import com.hcs.util.DebugUtil;
import com.hcs.weather.utils.HexUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.*;
import java.net.Socket;
import java.net.SocketException;

/**
 * 计算机连接网口
 *
 * @author lwt
 * @date 2018/07/15
 * @since 0.1.0
 */
public class PlcSocket {
    public enum CODE_TYPE {
        ASCII, //普通文本发送
        HEX    //十六进制发送
    }

    /**
     * ip
     */
    private String ip;
    /**
     * 端口
     */
    private int port;
    /**
     * 数据长度（对于定长值为0）
     */
    private int dataLength;
    /**
     * 编码方式
     */
    private String codeType;
    /**
     * 等待时间
     */
    private static final int DEFAULT_RANGE_FOR_SLEEP = 50;

    /**
     * 超时时间
     */
    private static final int DEFAULT_RANGE_TIME_OUT = 1000 * 60;

    /**
     * socket
     */
    private Socket socket = null;

    @Autowired
    private DebugUtil debugUtil;

    /**
     * logger
     */
    private final Logger logger = LoggerFactory.getLogger(PlcSocket.class);

    public PlcSocket(String ip, int port, int dataLength, String codeType) {
        this.ip = ip;
        this.port = port;
        this.dataLength = dataLength;
        this.codeType = codeType;
        if (!debugUtil.isDebug()) {
            try {
                socket = new Socket(ip, port);
                socket.setKeepAlive(true);
            } catch (Exception e) {
                logger.error("socket连接失败", e);
            }
        }
    }

    public synchronized String sendComm(String command) {
        if (debugUtil.isDebug()) {
            return "";
        }

        if (socket == null) {
            int i = 0;
            while (socket == null && i < 3) {
                try {
                    socket = new Socket(ip, port);
                    socket.setKeepAlive(true);
                } catch (IOException e) {
                    logger.error("socket连接失败", e);
                }
                try {
                    Thread.sleep(DEFAULT_RANGE_FOR_SLEEP);
                } catch (InterruptedException e) {
                    logger.error("系统内部错误", e);
                }
                i++;
            }
        }

        //超时
        try {
            socket.setSoTimeout(DEFAULT_RANGE_TIME_OUT);
        } catch (SocketException e) {
            try {
                if (!socket.isClosed()) {
                    socket.close();
                }
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            socket = null;
            return "";
        }

        //向网口发送数据
        OutputStream os = null;
        try {
            os = socket.getOutputStream();
            if (codeType.equals(CODE_TYPE.HEX.name())) {
                os.write(HexUtil.decode(command));
            } else {
                OutputStreamWriter opsw = new OutputStreamWriter(os);
                BufferedWriter bw = new BufferedWriter(opsw);
                bw.write(command);
            }
            os.flush();
        } catch (Exception e) {
            logger.error("向PLC发送命令失败!", e);
            return "";
        }

        //读取数据
        String result = "";
        InputStream inputStream = null;
        try {
            Thread.sleep(DEFAULT_RANGE_FOR_SLEEP);
            inputStream = socket.getInputStream();
            if (dataLength == 0) {
                //定长有换行符
                InputStreamReader ipsr = new InputStreamReader(inputStream);
                BufferedReader br = new BufferedReader(ipsr);
                result = br.readLine();
            } else {
                byte[] buffer = new byte[dataLength];
                int len = -1;
                if ((len = inputStream.read(buffer)) != -1) {
                    result = HexUtil.encode(buffer);
                }
            }
        } catch (Exception e) {
            logger.error("读取Socket信息失败", e);
        }
        return result;
    }

    public boolean connect() {
        return true;
    }

}