springboot+rxtx

在Spring Boot中使用RXTX进行串口通信，可以按照以下步骤进行：

1. 添加RXTX依赖

在pom.xml文件中添加以下依赖：

<dependency>
    <groupId>org.rxtx</groupId>
    <artifactId>rxtx</artifactId>
    <version>2.2</version>
</dependency>

2. 配置串口信息

在application.properties文件中添加以下配置信息：

serial.port.name=COM1 # 串口名称
serial.port.baudrate=9600 # 波特率
serial.port.databits=8 # 数据位
serial.port.stopbits=1 # 停止位
serial.port.parity=0 # 校验位

3. 创建SerialPortService类

创建一个SerialPortService类，用于打开、关闭串口，发送和接收数据。代码如下：

@Service
public class SerialPortService {

    private SerialPort serialPort;

    public void open(String portName, int baudRate, int dataBits, int stopBits, int parity) throws Exception {
        CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
        if (portIdentifier.isCurrentlyOwned()) {
            throw new Exception("Port is currently in use");
        } else {
            CommPort commPort = portIdentifier.open(this.getClass().getName(), 2000);
            if (commPort instanceof SerialPort) {
                serialPort = (SerialPort) commPort;
                serialPort.setSerialPortParams(baudRate, dataBits, stopBits, parity);
            } else {
                throw new Exception("Only serial ports are supported");
            }
        }
    }

    public void close() {
        if (serialPort != null) {
            serialPort.close();
        }
    }

    public void send(String data) throws Exception {
        if (serialPort != null) {
            OutputStream outputStream = serialPort.getOutputStream();
            outputStream.write(data.getBytes());
            outputStream.flush();
        } else {
            throw new Exception("Serial port is not open");
        }
    }

    public String receive() throws Exception {
        if (serialPort != null) {
            InputStream inputStream = serialPort.getInputStream();
            byte[] buffer = new byte[1024];
            int len = inputStream.read(buffer);
            return new String(buffer, 0, len);
        } else {
            throw new Exception("Serial port is not open");
        }
    }
}

4. 创建Controller类

创建一个Controller类，用于处理HTTP请求和WebSocket请求。代码如下：

@RestController
public class SerialPortController {

    @Autowired
    private SerialPortService serialPortService;

    @GetMapping("/open")
    public String open() throws Exception {
        serialPortService.open(
                Environment.getProperty("serial.port.name"),
                Integer.parseInt(Environment.getProperty("serial.port.baudrate")),
                Integer.parseInt(Environment.getProperty("serial.port.databits")),
                Integer.parseInt(Environment.getProperty("serial.port.stopbits")),
                Integer.parseInt(Environment.getProperty("serial.port.parity"))
        );
        return "Serial port is open";
    }

    @GetMapping("/close")
    public String close() {
        serialPortService.close();
        return "Serial port is closed";
    }

    @GetMapping("/send")
    public String send(@RequestParam String data) throws Exception {
        serialPortService.send(data);
        return "Data is sent";
    }

    @MessageMapping("/receive")
    @SendTo("/topic/receive")
    public String receive() throws Exception {
        return serialPortService.receive();
    }
}

5. 创建WebSocket配置类

创建一个WebSocket配置类，用于配置WebSocket。代码如下：

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        registry.enableSimpleBroker("/topic");
        registry.setApplicationDestinationPrefixes("/app");
    }

    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/ws").withSockJS();
    }
}

6. 创建WebSocket客户端

创建一个WebSocket客户端，用于向服务器发送WebSocket请求和接收服务器的响应。代码如下：

var stompClient = null;

function connect() {
    var socket = new SockJS('/ws');
    stompClient = Stomp.over(socket);
    stompClient.connect({}, function (frame) {
        console.log('Connected: ' + frame);
        stompClient.subscribe('/topic/receive', function (message) {
            console.log('Received: ' + message.body);
        });
    });
}

function send() {
    var data = document.getElementById('data').value;
    stompClient.send('/app/send', {}, data);
}

7. 创建HTML页面

创建一个HTML页面，用于测试串口通信。代码如下：

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Serial Port Test</title>
    <script src="/webjars/sockjs-client/1.5.0/dist/sockjs.min.js"></script>
    <script src="/webjars/stomp-websocket/2.3.3/dist/stomp.min.js"></script>
    <script src="/js/app.js"></script>
</head>
<body onload="connect()">
    <input type="text" id="data">
    <button onclick="send()">Send</button>
</body>
</html>