Installa libreria RXTX su os x

sono stanco di installare la libreria RXTX sul mio mac Voglio chiara discrezione, sto usando questo codice:

import java.io.*;
import java.util.*;
import gnu.io.*;

public class SimpleWrite {
static Enumeration portList;
static CommPortIdentifier portId;
static String messageString = "color FF00FFEND";
static SerialPort serialPort;
static OutputStream outputStream;

public static void main(String[] args) {
portList = CommPortIdentifier.getPortIdentifiers();


while (portList.hasMoreElements()) {

    portId = (CommPortIdentifier) portList.nextElement();
    if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {

         if (portId.getName().equals("/dev/cu.usbmodem1411")) {

            try {
                serialPort = (SerialPort)
                    portId.open("SimpleWriteApp", 2000);
            } catch (PortInUseException e) {System.out.println("err");}
            try {
                outputStream = serialPort.getOutputStream();
            } catch (IOException e) {System.out.println("err1");}
            try {
                serialPort.setSerialPortParams(9600,
                    SerialPort.DATABITS_8,
                    SerialPort.STOPBITS_1,
                    SerialPort.PARITY_NONE);
            } catch (UnsupportedCommOperationException e) {System.out.println("err2");}
            try {
                outputStream.write(messageString.getBytes());
    System.out.println(messageString);

    outputStream.close();
    serialPort.close();

            } catch (IOException e) {System.out.println("err3");}
        }
    }
}
}}

e io trovo sempre questo errore su molti codici

java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path thrown while loading gnu.io.RXTXCommDriver
Exception in thread "main" java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path

pls dammi il modo giusto