jSerialComm与Arduino UNO的串行通信失败

Arduino运行一个简单的草图,简单地返回计算机发送的值:

void setup() {
  Serial.begin(9600);

}

void loop() {
  if(Serial.available())
  Serial.println(Serial.read());
}

当我通过内置的串行监视器向它发送值时,它工作得很好。

我的Java代码似乎是问题所在,但我无法解决:

public static void main(String[] args){
    SerialPort port = SerialPort.getCommPort("COM5");
    port.setComPortParameters(9600,8,1,0);
    port.setComPortTimeouts(SerialPort.TIMEOUT_NONBLOCKING,0,0);
    System.out.println("Open port: " + port.openPort());
    try {
        Thread.sleep(100);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    Scanner in = new Scanner(port.getInputStream());
    PrintWriter out = new PrintWriter(port.getOutputStream(),true);

   out.println('a');
   out.flush();
    System.out.println("> w");

    while (in.hasNextLine())
        System.out.println("return: " +in.nextLine());
}

谢谢你的回复。

package sample;

import com.fazecast.jSerialComm.SerialPort;
import com.fazecast.jSerialComm.SerialPortDataListener;
import com.fazecast.jSerialComm.SerialPortEvent;

import java.io.PrintWriter;
import java.util.Scanner;
public class Test {
    static boolean received;
    public static void main(String[] args) {
        SerialPort port = SerialPort.getCommPort("COM5");
        port.setComPortParameters(9600,8,1,0);
        port.setComPortTimeouts(SerialPort.TIMEOUT_SCANNER,0,0);
        System.out.println("Open port: " + port.openPort());
        Scanner in = new Scanner(port.getInputStream());
        PrintWriter out = new PrintWriter(port.getOutputStream(),true);
        port.addDataListener(new SerialPortDataListener() {
            @Override
            public int getListeningEvents() {
                return SerialPort.LISTENING_EVENT_DATA_AVAILABLE;
            }

            @Override
            public void serialEvent(SerialPortEvent serialPortEvent) {
                String input = "";

               input = in.nextLine();

                System.out.println("return: " + input);
                received=true;
            }
        });


int counter =0;
        while(!received) {
            System.out.println(counter);
            out.println(counter);
            out.flush();
            try {
                Thread.sleep(20);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            counter++;
        }
        out.println('w');
        System.out.println("w");
           /*     String input = in.nextLine();
                System.out.println("return: "+input+input.isEmpty());*/
    }
}

Arduino的密码:

void setup() {
  Serial.begin(9600);

}
byte in;
int count=0;
void loop() {
  if(Serial.available()){
    Serial.print(Serial.parseInt());
    Serial.print('\n');
  }
}

开放端口:真 0
1

三
4
5
6

8
9
10

12

14
15
16


19

21
22
23
24
25
w

返回:0

这段代码应该立即返回计算机发送的值,但它没有。当我使用Arduino IDE中内置的串行监视器时,以及我尝试过的其他所有串行监视器时,它都能正常工作。