The best practical guide to RXTX serial and parallel I/O libraries in the Java class library
RXTX serial and parallel I/O libraries are commonly used in Java programs for processing serial and parallel communication.This article will introduce you to the best practical guide to use the RXTX library and provide Java code example.
The RXTX library is an open source Java class library for input and output operations on serial and parallel ports.By using the RXTX library, we can easily communicate with serial devices (such as sensors, robots, Arduino, etc.), and interact with parallel devices (such as printers, scanners, etc.).
Before starting using the RXTX library, we need to install the RXTX driver first.You can download the driver that suits your operating system that suits your operating system from the official RXTX official website (http://rxtx.qbang.org/wiki/index.php/main_page) and install it in accordance with their instructions.
After installing the driver, we can start writing the Java code to use the RXTX library for serial and parallel communication.Below is a simple example that shows how to use the RXTX library to read the data of the serial port:
import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import java.io.InputStream;
public class SerialPortExample {
public static void main(String[] args) {
try {
CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier("/dev/ttyUSB0");
if (portIdentifier.isCurrentlyOwned()) {
System.out.println("Error: Port is currently in use");
} else {
CommPort commPort = portIdentifier.open("SerialPortExample", 1000);
if (commPort instanceof SerialPort) {
SerialPort serialPort = (SerialPort) commPort;
serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
InputStream inputStream = serialPort.getInputStream();
byte[] buffer = new byte[1024];
int len = inputStream.read(buffer);
System.out.println("Received: " + new String(buffer, 0, len));
} else {
System.out.println("Error: Only serial ports are handled by this example.");
}
commPort.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
The above example code uses the COMMPORTIDENTIFIER class to obtain the identifier of the serial port and open a communication port through the Open method.Then, we check whether the communication port is a Serialport type and set the serial parameters.Next, we get the input stream of the serial port and read the data with the read method.Finally, we print out the received data.
Similarly, we can also use the RXTX library to communicate with parallel devices.Below is a simple example, showing how to use the RXTX library and printed string of parallel port:
import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.ParallelPort;
import java.io.OutputStream;
public class ParallelPortExample {
public static void main(String[] args) {
try {
CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier("LPT1");
if (portIdentifier.isCurrentlyOwned()) {
System.out.println("Error: Port is currently in use");
} else {
CommPort commPort = portIdentifier.open("ParallelPortExample", 1000);
if (commPort instanceof ParallelPort) {
ParallelPort parallelPort = (ParallelPort) commPort;
OutputStream outputStream = parallelPort.getOutputStream();
String message = "Hello, Parallel Port!";
byte[] bytes = message.getBytes();
outputStream.write(bytes);
outputStream.close();
} else {
System.out.println("Error: Only parallel ports are handled by this example.");
}
commPort.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
The above example code uses the same logic, which is only different in the operation of the communication port.We use the ParallelPort class to obtain the identifier of the parallel port and open a communication port through the Open method.Next, we obtain the output stream of parallel port, write the data through the WRITE method, and finally turn off the output stream.
Using RXTX serial and parallel I/O libraries can easily communicate with serial and parallel devices.When using, make sure that the driver has been installed correctly and adapt to the corresponding code logic according to needs.I hope this article can help you understand how to use the best practical guide to use the RXTX library.
