Java数字图像处理基础-------Java Swing简单使用，图形绘画---画五角星

要画出五角星出来，我们只需要在面板上产生5个点，然后把这5个点进行连接就可实现；

import javax.swing.*;
import java.awt.*;

public class FiveStar extends JPanel {
    Jframe jframe = new Jframe("五角星");
    int x1, x2, x3, x4, x5, y1, y2, y3, y4, y5;

    public FiveStar() {
        jframe.setSize(500, 500);
        this.setSize(500, 500);
        jframe.add(this);
        jframe.setVisible(true);
    }

    @Override
    protected void paintComponent(Graphics g) {
        x1 = this.getWidth() / 2;
        x2 = this.getWidth() / 8;
        x3 = this.getWidth() - x2;
        x4 = this.getWidth() / 4;
        x5 = 3 * this.getWidth() / 4;
        y1 = 50;
        y2 = this.getHeight() / 3;
        y3 = y2;
        y4 = this.getHeight() - 40;
        y5 = y4;
        int xPoints[] = {x2, x3, x4, x1, x5, x2};
        int yPoints[] = {y2, y3, y4, y1, y5, y2};
        g.setColor(Color.RED);
        // 求出5个点出来，直接画直线
        for (int i = 1; i < xPoints.length; i++) {
            g.drawLine(xPoints[i-1], yPoints[i-1], xPoints[i], yPoints[i]);
        }
    }

    public static void main(String[] args) {
        new FiveStar();
    }
}

案例仿照于：《Java数字图像处理基础编程技巧与应用实践》