java serial communication implementation process example

1, download 64 rxtx for java links: http: / / fizzed com oss/rxtx for -- java

2. Unzip the downloaded package and follow the instructions to put it under the installation path of JAVA_HOME or JAVA

3. Add under ES19en. xml of maven

  <dependency>
　　　　<groupId>org.rxtx</groupId>
　　　　<artifactId>rxtx</artifactId>
　　　　<version>2.1.7</version>
　　</dependency>

4. Serial port API

CommPort: Abstract class for ports
CommPortIdentifier: Core class for serial port access and control
SerialPort: It can read, write and set up the serial port directly

5. List the ports available on the machine

Enumeration<CommPortIdentifier> em = CommPortIdentifier.getPortIdentifiers();
　　while (em.hasMoreElements()) {
　　　　String name = em.nextElement().getName();
　　　　System.out.println(name);
　　}

6. General steps: Open the serial port to get the serial port object == "Setting parameters ==" To read and write to the serial port == "Closing the serial port, among which reading to the serial port is more commonly used

// Open the serial port 
　　CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier("COM4");//COM4 Serial port name 
　　CommPort commPort = portIdentifier.open("COM4", 2000);  //2000 Is the open timeout 
　　serialPort = (SerialPort) commPort;
　　// Set parameters (including baud rate, input / Output flow control, data bits, stop bits and parity) 
　　serialPort.setSerialPortParams(9600,
　　SerialPort.DATABITS_8, SerialPort.STOPBITS_1,
　　SerialPort.PARITY_NONE);
　　// Listen for serial port events 
　　serialPort.addEventListener(new Abc()); //Abc Is to realize the SerialPortEventListener Interface class in which the specific read operation is carried out 
　　//  Sets to wake up the listener receiving thread when data arrives 
　　serialPort.notifyOnDataAvailable(true);
　　//  Sets to wake up the interrupt thread when communication breaks 
　　serialPort.notifyOnBreakInterrupt(true);
　　//  in.close(); // Close a serial port 

Abc class content, namely the specific operation of reading serial port:

public class Abc implements SerialPortEventListener {
  public void serialEvent(SerialPortEvent arg0) {
    // TODO Auto-generated method stub
    // Judge and act on the following 
    /*
    BI - Communication interruption 
  　　CD - Carrier detect 
  　　CTS - Clear to send 
  　　DATA_AVAILABLE - Data arrives 
  　　DSR - Data set ready 
  　　FE - The frame error 
  　　OE - Overflow error 
  　　OUTPUT_BUFFER_EMPTY - The output buffer has been cleared 
  　　PE - Parity error 
    RI - Ringing indicating 
    */
    //switch More than one, if A single 
    if (arg0.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
      try {
        InputStream in = null;
        byte[] bytes = null;
        in = App.serialPort.getInputStream();

        int bufflenth = in.available();
        while (bufflenth != 0) {
          //  Initialize the byte The array is buffer The length of the data in 
          bytes = new byte[bufflenth];
          in.read(bytes);
          System.out.println(new String(bytes));
          bufflenth = in.available();
        }
        
      } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
  }  
}

Write operations:

OutputStream out = serialPort.getOutputStream();
out.write(data); //byte[] data;
out.flush();

conclusion

That is the end of this article on java serial communication implementation process examples, I hope to help you. If you have any questions, please feel free to leave a message and look forward to your valuable comments.