Plotting multiple Arduino Sensor Values data into a Java GUI

Question

I am working on an Arduino project which is complete. The next stage is for me to print the sensor values onto a GUI. I am using JFreeChart to do this. I have managed to plot one sensor reading however, I am unable to plot the other two. The only sensor readings I have managed to plot is the LDR however, I believe it is plotting them all onto one line but I would like this to be seperate. So since there are a total of three sensors, I would like there to be three seperate lines on the line graph. I am struggling to add series and datasets to get this working. I have also managed to create seperate charts but they all output the same results but this shouldn't be the case they should output different results.. here is my code:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Scanner;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import com.fazecast.jSerialComm.SerialPort;

public class SensorGraph {

static SerialPort chosenPort;
static int x = 0;

public static void main(String[] args) {

    // create and configure the window
    JFrame window = new JFrame();
    window.setTitle("Sensor Graph GUI");
    window.setSize(600, 400);
    window.setLayout(new BorderLayout());
    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // create a drop-down box and connect button, then place them at the top of the window
    JComboBox<String> portList = new JComboBox<String>();
    JButton connectButton = new JButton("Connect");
    JPanel topPanel = new JPanel();
    topPanel.add(portList);
    topPanel.add(connectButton);
    window.add(topPanel, BorderLayout.NORTH);

    // populate the drop-down box
    SerialPort[] portNames = SerialPort.getCommPorts();
    for(int i = 0; i < portNames.length; i++)
        portList.addItem(portNames[i].getSystemPortName());

    // create the line graph
    XYSeries series = new XYSeries("Light Sensor Readings");
    XYSeries series2 = new XYSeries("Pressure Pad Readings");
    XYSeries series3 = new XYSeries("Ultrasonic Sensor Readings");


    XYSeriesCollection dataset = new XYSeriesCollection(series);
    JFreeChart chart = ChartFactory.createXYLineChart("Light Sensor Readings", "Time (seconds)", "ADC Reading", dataset);
    window.add(new ChartPanel(chart), BorderLayout.CENTER);

    // configure the connect button and use another thread to listen for data
    connectButton.addActionListener(new ActionListener(){
        @Override public void actionPerformed(ActionEvent arg0) {
            if(connectButton.getText().equals("Connect")) {
                // attempt to connect to the serial port
                chosenPort = SerialPort.getCommPort(portList.getSelectedItem().toString());
                chosenPort.setComPortTimeouts(SerialPort.TIMEOUT_SCANNER, 0, 0);
                if(chosenPort.openPort()) {
                    connectButton.setText("Disconnect");
                    portList.setEnabled(false);
                }

                // create a new thread that listens for incoming text and populates the graph
                Thread thread = new Thread(){
                    @Override public void run() {
                        Scanner scanner = new Scanner(chosenPort.getInputStream());
                        while(scanner.hasNextLine()) {
                            try {
                                String line = scanner.nextLine();
                                int number = Integer.parseInt(line);
                                series.add(x++, 1023 - number);
                                window.repaint();
                            } catch(Exception e) {}
                        }
                        scanner.close();
                    }
                };
                thread.start();
            } else {
                // disconnect from the serial port
                chosenPort.closePort();
                portList.setEnabled(true);
                connectButton.setText("Connect");
                series.clear();
                x = 0;
            }
        }
    });

    // show the window
    window.setVisible(true);
}

}