java 2D图形绘制

package jisuan;import java.awt.Dimension;import java.awt.EventQueue;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.geom.Ellipse2D;import java.awt.geom.Line2D;import java.awt.geom.Rectangle2D;import javax.swing.JComponent;import javax.swing.JFrame;public class Drawtest {    public static void main(String[] args) {        EventQueue.invokeLater(new Runnable() {            @Override            public void run() {                JFrame frame = new DrawFrame();                frame.setTitle("计算器");                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);                frame.setVisible(true);            }        });    }}class DrawFrame extends JFrame{    /**     * 创建一个窗口     */    private static final long serialVersionUID = 1L;    public DrawFrame() {        add(new DrawComponent());        pack();    }}class DrawComponent extends JComponent{    /**     * 画图     */    private static final long serialVersionUID = 1L;    private static final int DEFAULT_WIDTH = 400;    private static final int DEFAULY_HEIQHT = 400;    public void paintComponent(Graphics g) {        Graphics2D g2 = (Graphics2D)g;        double leftX = 100;        double topY = 100;        double width = 200;        double height = 150;        //长方形        Rectangle2D rect = new Rectangle2D.Double(leftX, topY , width , height);        g2.draw(rect);        //椭圆        Ellipse2D ellipse = new Ellipse2D.Double();        ellipse.setFrame(rect);        g2.draw(ellipse);        //画斜线        g2.draw(new Line2D.Double(leftX ,topY ,leftX + width, topY + height));        //大园        double centerX = rect.getCenterX();        double centerY = rect.getCenterY();        double radius = 150;        Ellipse2D circle = new Ellipse2D.Double();        circle.setFrameFromCenter(centerX, centerY, centerX + radius, centerY + radius);        g2.draw(circle);    }    public Dimension getPreferredSize() {        return new Dimension(DEFAULT_WIDTH, DEFAULY_HEIQHT);    }}