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);

}
}