实现效果：

源代码：

package sponge;import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Polygon;import javax.swing.JFrame;public class Sponge_Main extends JFrame implements Runnable{public static void main(String[]  args) {Sponge_Main mf = new Sponge_Main();mf.initUI();}Point[] pn = new Point[20];public void paint(Graphics g) {super.paint(g);//正方形的顶点坐标int x = 100,y = 500;int d = 120,dx = 81,dy = 60;Point p0 = new Point(x,y);drawBottomLevel(g,p0,d,dx,dy);Point p1 = new Point(x,y-d);drawMidLevel(g,p1,d,dx,dy);Point p2 = new Point(x,y-2*d);drawTopLevel(g,p2,d,dx,dy);//----------for(int i = 0;i<pn.length;i++) {Point ptem = pn[i];if(ptem!=null) {Point ptem0 = new Point(pn[i].x,pn[i].y+2*d/3); drawBottomLevel(g,ptem0,d/3,dx/3,dy/3);Point ptem1 = new Point(pn[i].x,pn[i].y+d/3);drawMidLevel(g,ptem1,d/3,dx/3,dy/3);Point ptem2 = new Point(pn[i].x,pn[i].y);drawTopLevel(g,ptem2,d/3,dx/3,dy/3);}}}//根据起点p0得到另外6个点public Point[] getPointByP0(Point p0,int d,int dx,int dy) {Point p1 = new Point(p0.x+dx,p0.y-dy);Point p2 = new Point(p0.x+dx+d,p0.y-dy);Point p3 = new Point(p0.x+d,p0.y);Point p4 = new Point(p0.x+d,p0.y+d);Point p5 = new Point(p0.x,p0.y+d);Point p6 = new Point(p0.x+dx+d,p0.y+d-dy);Point[] ps = new Point[7];ps[0] = p0;ps[1] = p1;ps[2] = p2;ps[3] = p3;ps[4] = p4;ps[5] = p5;ps[6] = p6;return ps;}int count = 0;//递归次数public void draw(Graphics g,Point p0,Point p1,Point p2,Point p3,Point p4,Point p5,Point p6) {if(count<20) {pn[count] = p0;}count++;//三原色
//      int c1 = new java.util.Random().nextInt(255);
//      int c2 = new java.util.Random().nextInt(255);
//      int c3 = new java.util.Random().nextInt(255);Graphics2D gD = (Graphics2D) g;//填充面的颜色Polygon pon1 = new Polygon();//填充第一个可见面pon1.addPoint(p0.x, p0.y);pon1.addPoint(p1.x, p1.y);pon1.addPoint(p2.x, p2.y);pon1.addPoint(p3.x, p3.y);gD.setColor(new Color(230,0,0));gD.fillPolygon(pon1);//填充第二个可见面Polygon pon2 = new Polygon();pon2.addPoint(p0.x, p0.y);pon2.addPoint(p3.x, p3.y);pon2.addPoint(p4.x, p4.y);pon2.addPoint(p5.x, p5.y);gD.setColor(new Color(255,0,0));gD.fillPolygon(pon2);//填充第三个可见面Polygon pon3 = new Polygon();pon3.addPoint(p2.x, p2.y);pon3.addPoint(p3.x, p3.y);pon3.addPoint(p4.x, p4.y);pon3.addPoint(p6.x, p6.y);gD.setColor(new Color(200,0,0));gD.fillPolygon(pon3);}public void drawBottomLevel(Graphics g, Point p0, int d, int dx, int dy) {Point[] ps1 = getPointByP0(p0,d,dx,dy);Point[] ps2 = getPointByP0(ps1[3],d,dx,dy);Point[] ps3 = getPointByP0(ps2[3],d,dx,dy);Point[] ps4 = getPointByP0(ps3[1],d,dx,dy);Point[] ps5 = getPointByP0(ps4[1],d,dx,dy);Point[] ps6 = getPointByP0(ps1[1],d,dx,dy);Point[] ps7 = getPointByP0(ps6[1],d,dx,dy);Point[] ps8 = getPointByP0(ps7[3],d,dx,dy);draw(g,ps7[0],ps7[1],ps7[2],ps7[3],ps7[4],ps7[5],ps7[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps8[0],ps8[1],ps8[2],ps8[3],ps8[4],ps8[5],ps8[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps5[0],ps5[1],ps5[2],ps5[3],ps5[4],ps5[5],ps5[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps4[0],ps4[1],ps4[2],ps4[3],ps4[4],ps4[5],ps4[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps6[0],ps6[1],ps6[2],ps6[3],ps6[4],ps6[5],ps6[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps1[0],ps1[1],ps1[2],ps1[3],ps1[4],ps1[5],ps1[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps2[0],ps2[1],ps2[2],ps2[3],ps2[4],ps2[5],ps2[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}draw(g,ps3[0],ps3[1],ps3[2],ps3[3],ps3[4],ps3[5],ps3[6]);try {Thread.sleep(100);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public void drawMidLevel(Graphics g, Point p0, int d, int dx, int dy) {Point[] ps1 = getPointByP0(p0,d,dx,dy);Point[] ps2 = getPointByP0(ps1[3],d,dx,dy);Point[] ps3 = getPointByP0(ps2[3],d,dx,dy);Point[] ps4 = getPointByP0(ps3[1],d,dx,dy);Point[] ps5 = getPointByP0(ps4[1],d,dx,dy);Point[] ps6 = getPointByP0(ps1[1],d,dx,dy);Point[] ps7 = getPointByP0(ps6[1],d,dx,dy);Point[] ps8 = getPointByP0(ps7[3],d,dx,dy);draw(g,ps7[0],ps7[1],ps7[2],ps7[3],ps7[4],ps7[5],ps7[6]);draw(g,ps5[0],ps5[1],ps5[2],ps5[3],ps5[4],ps5[5],ps5[6]);draw(g,ps1[0],ps1[1],ps1[2],ps1[3],ps1[4],ps1[5],ps1[6]);draw(g,ps3[0],ps3[1],ps3[2],ps3[3],ps3[4],ps3[5],ps3[6]);}public void drawTopLevel(Graphics g, Point p0, int d, int dx, int dy) {Point[] ps1 = getPointByP0(p0,d,dx,dy);Point[] ps2 = getPointByP0(ps1[3],d,dx,dy);Point[] ps3 = getPointByP0(ps2[3],d,dx,dy);Point[] ps4 = getPointByP0(ps3[1],d,dx,dy);Point[] ps5 = getPointByP0(ps4[1],d,dx,dy);Point[] ps6 = getPointByP0(ps1[1],d,dx,dy);Point[] ps7 = getPointByP0(ps6[1],d,dx,dy);Point[] ps8 = getPointByP0(ps7[3],d,dx,dy);draw(g,ps7[0],ps7[1],ps7[2],ps7[3],ps7[4],ps7[5],ps7[6]);draw(g,ps8[0],ps8[1],ps8[2],ps8[3],ps8[4],ps8[5],ps8[6]);draw(g,ps5[0],ps5[1],ps5[2],ps5[3],ps5[4],ps5[5],ps5[6]);draw(g,ps4[0],ps4[1],ps4[2],ps4[3],ps4[4],ps4[5],ps4[6]);draw(g,ps6[0],ps6[1],ps6[2],ps6[3],ps6[4],ps6[5],ps6[6]);draw(g,ps1[0],ps1[1],ps1[2],ps1[3],ps1[4],ps1[5],ps1[6]);draw(g,ps2[0],ps2[1],ps2[2],ps2[3],ps2[4],ps2[5],ps2[6]);draw(g,ps3[0],ps3[1],ps3[2],ps3[3],ps3[4],ps3[5],ps3[6]);}public void initUI() {this.setTitle("门格海绵");this.setSize(1000, 800);this.setDefaultCloseOperation(3);this.setResizable(false);this.setLocationRelativeTo(null);this.setVisible(true);}@Overridepublic void run() {// TODO Auto-generated method stub}
}