java调试串口，与硬件通信

开发过程中碰到通过串口连接设备的需求，记录一下。在spring环境下。在启动项目时打开串口。

 

import gnu.io.CommPortIdentifier;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.UnsupportedCommOperationException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PostConstruct;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;

@Configuration
public class RS485Config {

    private final static Logger LOGGER = LoggerFactory.getLogger(RS485Config.class);

    static CommPortIdentifier portId;
    static Enumeration<?> portList;

    // 从串口输入流
    InputStream inputStream;
    // 向串口输出流
    public static OutputStream outputStream;
    // 串口的引用
    static SerialPort serialPort;
    
    @Value("${rs485enableFlag:false}")
    private boolean rs485enableFlag = false;

    @PostConstruct
    public void openPorts() {
        
        if (!rs485enableFlag) {
            LOGGER.info("********** 串口设备未启用，请检查rs485enableFlag配置 **********");
            return;
        }

        RS485Config cRead = new RS485Config();
        int i = cRead.startComPort();
        if (i == 1) {
            LOGGER.info("********** 成功打开串口 **********");
        } else {
            return;
        }
    }

    /**
     * 通过程序打开COM3串口，设置监听器以及相关的参数
     *
     * @return 返回1 表示端口打开成功，返回 0表示端口打开失败
     */
    public int startComPort() {
        // 通过串口通信管理类获得当前连接上的串口列表
        portList = CommPortIdentifier.getPortIdentifiers();
        while (portList.hasMoreElements()) {
            // 获取相应串口对象
            portId = (CommPortIdentifier) portList.nextElement();
            LOGGER.info("********** 设备类型 [{}] **********", portId.getPortType());
            LOGGER.info("********** 设备名称 [{}] **********", portId.getName());
            // 判断端口类型是否为串口
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                // 判断如果COM3串口存在，就打开该串口
                if (portId.getName().equals(portId.getName())){
                    try {
                        // 打开串口名字为COM_3(名字任意),延迟为1000毫秒
                        serialPort = (SerialPort) portId.open(portId.getName(), 1000);
                    } catch (PortInUseException e) {
                        LOGGER.error("********** 打开端口失败 **********", e);
                        return 0;
                    }
                    // 设置当前串口的输入输出流
                    try {
                        inputStream = serialPort.getInputStream();
                        outputStream = serialPort.getOutputStream();
                    } catch (IOException e) {
                        LOGGER.error("********** 打开端口失败 **********", e);
                        return 0;
                    }
                    // 设置监听器生效，即：当有数据时通知
                    serialPort.notifyOnDataAvailable(true);
                    // 设置串口的一些读写参数
                    try {
                        // 比特率、数据位、停止位、奇偶校验位-------比特率每个设备可能不一样，根据设备本身的值设置
                        serialPort.setSerialPortParams(9600,
                                SerialPort.DATABITS_8, SerialPort.STOPBITS_1,
                                SerialPort.PARITY_NONE);
                    } catch (UnsupportedCommOperationException e) {
                        LOGGER.error("********** 打开端口失败 **********", e);
                        return 0;
                    }
                    return 1;
                }
            }
        }
        return 0;
    }

}

使用的地方获取串口输入输出流即可，关键代码如下

if (RS485Config.outputStream != null) {
//order 是要发送相关指令，根据实际情况来。。循环发送，for循环略。
 RS485Config.outputStream.write(order.getBytes());
RS485Config.outputStream.flush();
while ((c = RS485Config.inputStream.read()) != -1) {
          sb.append((char)c);
         }
           String reciveMsg =sb.toString();
             //全部转成小写
          if (!reciveMsg.toLowerCase().contains("OK".toLowerCase())) {
             logger.info("指令发送失败 response: {}", sb);
              break;
           } else {
            logger.debug("指令发送成功 response: {}", sb);
            continue;
    }
}

 

循环检验设备比特率的方法，有的设备不知道比特率是多少，列举常用比特率多次尝试

mport gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

public class CommUtil {

    private static final Logger logger = LoggerFactory.getLogger(CommUtil.class);
    private static final int[] baudRates = {9600, 19200, 57600, 115200};//常用比特率

    public static void getCommPortDevices() {
        logger.info("Detecting serial comm　devices...");
        Enumeration<CommPortIdentifier> portList = CommPortIdentifier.getPortIdentifiers();
        while (portList.hasMoreElements()) {
            CommPortIdentifier portId = portList.nextElement();    //portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                logger.info("Found serial comm device: {}", portId.getName());
                for (int baudRate : baudRates) {
                    logger.info("  Trying at {} ...", baudRate);
                    SerialPort serialPort = null;
                    try {
                        String re = "at+cscs=\"gsm\"\r"; //硬件相关指令，根据实际设备来填写
                        serialPort = (SerialPort) portId.open(portId.getName(), 1000);
                        serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_RTSCTS_IN);
                        serialPort.setSerialPortParams(baudRate, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
                        InputStream inStream = serialPort.getInputStream();
                        OutputStream outStream = serialPort.getOutputStream();
                        serialPort.enableReceiveTimeout(1000);
                        int c;
                        while ((c = inStream.read()) != -1) {
                            // do nothing;
                        }
                        outStream.write(re.getBytes());

                        StringBuilder sb = new StringBuilder();
                        while ((c = inStream.read()) != -1) {
                            sb.append((char)c);
                        }
                        if (!sb.toString().contains("OK")) {
                            logger.info("    No device detected, response: {}", sb);
                        } else {
                            logger.info("    Device found,");
                            sb.setLength(0); // clear the StringBuilder
                            outStream.write("AT+CGMM\r".getBytes());
                            while ((c = inStream.read()) != -1) {
                                sb.append((char)c);
                            }
                            String model = sb.toString()
                                    .replaceAll("(\n|\r|AT\\+CGMM|OK)", "")
                                    .replaceAll("\\s+", " ").trim();
                            logger.info("    Device model: {}", model);
                            break;
                        }
                    } catch (Exception e) {
                        logger.error(e.getMessage(), e);
                    } finally {
                        if (serialPort != null) {
                            serialPort.close();
                        }
                    }
                }
            }
        }
        //return devices;
    }

    public static void main(String[] args) {
       getCommPortDevices();
        //logger.info("size: {}", devices.size());
    }
}