Swing-不规则形状绘制（圆弧）

 核心代码：

package swing0401;

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.font.TextAttribute;
import java.awt.geom.Arc2D;
import java.awt.geom.Path2D;
import java.util.HashMap;
import java.util.Map;

import javax.swing.JPanel;

public class MyPanel extends JPanel
{
	public MyPanel()
	{
		
	}

	@Override
	protected void paintComponent(Graphics g) 
	{
		int width=this.getWidth();
		int height=this.getHeight();
		Graphics2D g2d=(Graphics2D)g;
		
		//平滑绘制
		g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
				
		g2d.setPaint(Color.WHITE);
		g2d.fillRect(0, 0, width, height);
		
		//指定一个外围矩形
		Rectangle rect=new Rectangle(30,30,100,100);
		g2d.setPaint(Color.DARK_GRAY);
		g2d.draw(rect);
		
		
		g2d.setPaint(Color.GREEN);
		//创建一个Arc(弧)
		//Arc2D.OPEN(圆弧)  ,Arc2D.CHORD(弓形)  ,Arc2D.PIE(扇形)
		Shape shape=new Arc2D.Double(rect,0,120,Arc2D.PIE);//120代表跨度
		g2d.draw(shape);
 
		
	
		
	}
	
}