一、序言
关于“Java做不好桌面”的争论已经由来已久。虽然Swing和Java2D已经有超 过十年的历史，也有JIDE、JGoodies、TWaver等不少开源Swing组件，但是用 Java做桌面程序仍然不是一件轻松的事。本《Java也惊艳》系列文章，就是想通 过一些简单生动的例子，和大家一起认识Java、探索Swing。其实你只需要多一 点创意、多一点耐心，你的Java程序也可以“惊艳”！本文就带您一起进入Java 的惊艳之旅。
二、立体套管效果
在网络通讯中，经常要表达协议之间的“承载”关系。例如，IP协议作为高 层协议可以承载在SDH上，也可以承载在ATM协议上。同样，IP作为协议还可以承 载更多的高层协议，例如Voice over IP，甚至电信中Everything over IP的概 念。在表现上，用相互嵌套的立体套管来表现协议的“承载”是再合适不过了（ 如下图）。
具体实现很简单，主要代码如下：
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import twaver.*;
public class PipleComponent extends JComponent {
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint (RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
Shape parentHollowShape=createPiple (g2d,100,100,200,200,TWaverUtil.getRandomColor(),null);
createPiple (g2d,120,120,280,40,TWaverUtil.getRandomColor (),parentHollowShape);
createPiple (g2d,130,170,310,40,TWaverUtil.getRandomColor (),parentHollowShape);
createPiple (g2d,140,220,290,50,TWaverUtil.getRandomColor (),parentHollowShape);
createPiple (g2d,130,190,300,30,TWaverUtil.getRandomColor (),parentHollowShape);
}
private Shape createPiple(Graphics2D g2d,int x, int y, int width, int height,Color color,Shape parentHollowShape) {
if(parentHollowShape!=null){
Rectangle bounds=parentHollowShape.getBounds();
Rectangle rightClip=new Rectangle (bounds.x+bounds.width/2,bounds.y,3000,bounds.height);
Area clip=new Area (parentHollowShape);
clip.add(new Area(rightClip));
g2d.setClip(clip);
}
int circleWidth = height/3;
GradientPaint paint = new GradientPaint(x,
y,
color.brighter(),
x,
y + (int) (height * 0.65),
color.darker(),
true);
g2d.setPaint(paint);
Ellipse2D.Double leftCircle = new Ellipse2D.Double(x - circleWidth / 2, y, circleWidth, height);
Ellipse2D.Double rightCircle = new Ellipse2D.Double(x + width - circleWidth / 2, y, circleWidth, height);
int thickness=4;
Ellipse2D.Double rightHollowCircle = new Ellipse2D.Double(rightCircle.getX()+thickness,
rightCircle.getY()+thickness,
rightCircle.getWidth()-thickness*2,
rightCircle.getHeight()- thickness*2);
Rectangle rect = new Rectangle(x, y, width, height);
Area area = new Area(leftCircle);
area.add(new Area(rect));
area.subtract(new Area(rightCircle));
g2d.fill(area);
g2d.setColor(color.darker());
g2d.fill(rightCircle);
paint = new GradientPaint(x,
y,
Color.darkGray,
x,
y + (int) (height * 0.4),
Color.lightGray,
true);
g2d.setPaint(paint);
g2d.fill(rightHollowCircle);
g2d.setClip(null);
return rightHollowCircle;
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.setSize(800, 600);
frame.add(new PipleComponent());
frame.setVisible(true);
}
}