卡在绘制一组数据点（x，y）上

Question

Edited with CMilbys suggestion, However i'm getting an error when adding "replayData to the frame.

Here is the replayData class + paint method

public class ReplayData extends JPanel {
/**
 * 
 */
private static final long serialVersionUID = 1L;
private ArrayList<Point> points;

// Create new list of points when ready then call Redraw()
public void ReplaceData() {
    points = new ArrayList<Point>();
}

public void addPoint(Point point) {
    points.add(point);
}

@Override
public void paintComponent(Graphics g) {
    super.paintComponent(g);

    for (Point p : points) 
        g.fillRect(p.x, p.y, 2, 2);
}

public void draw() {
    repaint();
   }
}

And here is where I try to call it to print all of the records that have been retrieved from the csv

    JButton button_KMeans = new JButton("View K-Means");
    button_KMeans.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            kMeans.initialize();
            kMeans.kMeanCluster();

            //for (Point p : kMeans.getPoints() )
            // Will this be very slow? Data sets are going to be large
            Point temp = new Point();
            for (int i = 0; i < kMeans.TOTAL_DATA; i++)
            {           
                temp.x = (int)TrackerData.getRecordNumber(i).getEyeX();
                temp.y = (int)TrackerData.getRecordNumber(i).getEyeY();
                replayData.addPoint(temp); // Add points to JPanel
            }
            replayData.draw();  
            // How could I make it so this data shows over like 5 seconds, or over 30 etc?
        }
    });

I'm getting errors when adding the instance of ReplayData to the frame

at javax.swing.JFrame.addImpl(Unknown Source)

at java.awt.Container.add(Unknown Source)

 private ReplayData replayData;

 private void initialize() {

    frame = new JFrame();
    frame.setBounds(100, 100, 1920, 1080);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().setLayout(null);
    frame.add(replayData);  // if I comment this line the program starts fine

Answer 1

In your paintComponent method you should call super.paintComponent. That was correct so uncomment that.

Secondly, your ReplayData class extends JPanel. Because of this you need to use JFrame's add method and add an instance of the class to the JFrame. This will only allow you to have 1 point though. So I recommend you re-structure your class to have an array of points and not two integer variables which it what it appears to be. So for example

class ReplayDate extends JPanel {
    private List<Point> points;

    public ReplaceData() {
        points = new ArrayList<Point>();
    }

    public void addPoint(Point point) {
        points.add(point);
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        for (Point p : points) 
            g.fillRect(point.x, point.y, 2, 2);
    }

    public void draw() {
        repaint();
    }
}

// In your Main class
private ReplayData replayData;

private void initialize() {
    frame = new JFrame();
    frame.setBounds(100, 100, 1920, 1080);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().setLayout(null);
    frame.add(replayData); // Add replay data to jframe
    JButton button_KMeans = new JButton("View K-Means");
    button_KMeans.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent arg0) {
        kMeans.initialize();
        kMeans.kMeanCluster();
        for (Point p : kMeans.getPoints()
            replayData.addPoint(p); // Add points to JPanel
        replayData.draw();  
    } 
}

This will allow you to add any number of points and draw them all. I hope this answered your question. If you are still confused just leave a comment and I will try to explain a little more.

EDIT: To help with a few more problems... First: When setting the size of a JFrame, yours seems to work since you said nothing about it, however, I've never actually used that method. For future reference it can also be done like this.

jframe.getContentPane().setPreferredSize(new Dimension(width, height));

As for when you add a ReplayData instance to your JFrame, I'm not sure about that one... I copied your code into a compiler and it worked fine for me. Post more code or send me your project and I can take a deeper look.

Lastly, you're worried about speed. How large are your datasets? This also depends on your computer. My computer has a 2.4 GHz Intel Core i5. Since 1 hertz is '1/second', assuming I did this math right, and in an ideal world it could do 2.4 billion operations per second. This obviously isn't the actual case but my point is even with datasets of ~10,000, you will probably notice a small delay, but it will only be seconds.