Java AWT Graphics2D transform translate

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel {
  Random rnd = new Random();
  @Override//from w  w  w.  j a v a2  s  .  com
  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    
    Graphics2D g2d = (Graphics2D) g;
    g2d.setBackground(Color.WHITE);
    g2d.clearRect(0, 0, getParent().getWidth(), getParent().getHeight());
    // antialising
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);


    // Blue line
    g2d.setPaint(Color.BLUE);
    Stroke solidStroke = new BasicStroke(10, BasicStroke.CAP_ROUND, 
            BasicStroke.JOIN_ROUND);
    g2d.setStroke(solidStroke);
    g2d.draw(new Line2D.Float(new Point2D.Float(200, 10), 
            new Point2D.Double(10, 210)));
    
    g2d.translate(100, 100);
    
    g2d.draw(new Line2D.Float(new Point2D.Float(200, 10), 
        new Point2D.Double(10, 210)));
    
  }

  public static void main(String[] args) {
    // create frame for Main
    JFrame frame = new JFrame("java2s.com");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Main Main = new Main();
    frame.add(Main);
    frame.setSize(300, 210);
    frame.setVisible(true);
  }
}

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.GeneralPath;
import java.security.SecureRandom;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel {
  @Override/*from  ww  w . ja  va2s  .c  o m*/
  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g; // cast g to Graphics2D

    int[] xPoints = { 55, 67, 109, 73, 83, 55, 27, 37, 1, 43 };
    int[] yPoints = { 0, 36, 36, 54, 96, 72, 96, 54, 36, 36 };

    GeneralPath star = new GeneralPath(); // create GeneralPath object

    // set the initial coordinate of the General Path
    star.moveTo(xPoints[0], yPoints[0]);

    // create the star--this does not draw the star
    for (int count = 1; count < xPoints.length; count++)
      star.lineTo(xPoints[count], yPoints[count]);

    star.closePath(); // close the shape
    
    g2d.translate(150, 150); // translate the origin to (150, 150)

    // rotate around origin and draw stars in random colors
    SecureRandom random = new SecureRandom(); 
    for (int count = 1; count <= 20; count++) 
    {
       g2d.rotate(Math.PI / 10.0); // rotate coordinate system

       // set random drawing color
       g2d.setColor(new Color(random.nextInt(256),
          random.nextInt(256), random.nextInt(256)));

       g2d.fill(star); // draw filled star
    }     
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("Drawing 2D shapes");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Main Main = new Main();
    frame.add(Main);
    frame.setSize(425, 200);
    frame.setVisible(true);
  }
}