How to draw a two dimensional graphic at Java?

Question

I have 2 different lists. Each of them holds x and y value pairs(they have both positive and negative values). How can I draw them on a 2D axis? I want to put points for every value and they will blue for first list and red for second list.

My lists' type:

List<List<Double>>

List<Double> inside of List<...> has 2 variables, first of it for x value and the second one is for y value.

However just I need to how to draw a two dimensional graphic at Java(desktop application) and put points wherever I want, improving code for my variables is less important.

PS:

I want the more and more simple of that kind of graphic:

Something like:

Answer 1

you could use a library like http://www.jfree.org/jfreechart/ (LGPL-License) there are lots of examples around the web, and it's quite easy to use.

here's an example, that seems to match your requirements:

http://www.java2s.com/Code/Java/Chart/JFreeChartMarkerDemo1.htm

Answer 2

Assuming you are using Swing with a panel, you can use the following:

public class JImagePanelExample extends JPanel {

    private BufferedImage image;
    private Graphics2D drawingBoard;
    private int x, y; // Image position in the panel

    // Let's assume image is a chart and you need to draw lines
    public JImagePanelExample(BufferedImage image, int x, int y) {

        super();
        this.image = image;

        // Retrieving a mean to draw lines
        drawingBoard = image.createGraphics();

        // Draw what you need to draw (see other methods too)
        drawingBoard.drawLine(0, 10, 35, 55);

    }

    // Called by Swing to draw the image in the panel
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(image, x, y, null);
    }

}

If you don't want to use Swing and you just need to draw in 2D, focus on BufferedImage and Graphics2D only.

Answer 3

There is a Java 2D API: http://java.sun.com/products/java-media/2D/ and many charting libraries easily found with a web search.