Java实现串口读写数据

Question

Java实现串口，我已经实现了读取数据，但是往串口发送数据一点都不会，下面是我的读取数据的代码，请问怎么在下面的代码基础上增加往串口发送数据的功能

public class VersolApplication {

    // 设定MODBUS网络上从站地址
    private final static int SLAVE_ADDRESS = 201;
    //串行波特率
    private final static int BAUD_RATE = 9600;

    public static void main(String[] args) {
        SpringApplication.run(VersolApplication.class, args);
        try {
            Runtime.getRuntime().exec("cmd /c start http://localhost:8080/index");
            modbus(args);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void modbus(String[] args){
        SerialPortWrapper serialParameters = new
                SerialPortWrapperImpl("COM3", BAUD_RATE, 8, 1, 0, 0, 0);
        /* 创建ModbusFactory工厂实例 */
        ModbusFactory modbusFactory = new ModbusFactory();
        /* 创建ModbusMaster实例 */
        ModbusMaster master = modbusFactory.createRtuMaster(serialParameters);
        /* 初始化 */
        try {
            master.setTimeout(3000);
            master.setRetries(3);
            master.init();
            readHoldingRegistersTest(master, SLAVE_ADDRESS, 79, 4);
        } catch (ModbusInitException e) {
            e.printStackTrace();
        } finally {
            master.destroy();
        }
    }

    private static void readHoldingRegistersTest(ModbusMaster master, int slaveId, int start, int len) {
        try {
            ReadHoldingRegistersRequest request = new ReadHoldingRegistersRequest(slaveId, start, len);
            ReadHoldingRegistersResponse response = (ReadHoldingRegistersResponse)master.send(request);
            if (response.isException()) {
                System.out.println("Exception response: message=" + response.getExceptionMessage());
            } else {
                System.out.println("success"+ Arrays.toString(response.getShortData()));
                short[] list = response.getShortData();
                for (int i = 0; i < list.length; i++) {
                    System.out.print(list[i] + " ");
                }
            }
        } catch (ModbusTransportException e) {
            e.printStackTrace();
        }
    }

}

Answer 1

read是读，write就是写，你调用write就行了

Answer 2

直接调用吗？可是我没有定义这个write方法呀？是要自己定义吗？

Answer 3

read也不是你定义的，你调用的是ReadHoldingRegistersRequest，只不过自己又重新封装了一下
write也调用类库里提供的write即可

Answer 4

那我这个方法是在启动类里面，我能在service层调用吗？