题目： 实现一个画板，根据选择，画出不同形状的图形。

自己写的: 1.Shape:

    package demo.panel;public abstract class Shape {	protected abstract void draw();}

2.圆，正方形

    package demo.panel;public class Circle extends Shape{	@Override	protected void draw() {		System.out.println("now draw a circle!");	}}package demo.panel;public class Rectangle extends Shape {	@Override	protected void draw() {		System.out.println("now draw a rectangle");	}}

实现： 我的：

     package demo.panel;import java.io.BufferedReader;import java.io.InputStreamReader;public class Panel {	public void selectShape(int shape){		Shape sh=null;		switch (shape) {		case 0:			sh = new Circle();			break;		case 1:			sh = new Rectangle();		default:			break;		}		if(sh==null){			System.out.println("your input shaple is not find!");		}else{			sh.draw();		}	}	public static void main(String[] args) throws Exception {		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));		int shapeType =  Integer.parseInt(br.readLine());    	    Panel panel  = new Panel();    	    panel.selectShape(shapeType);    	}    }

别人的写法： 把selectShape里面独立一个工厂模式，产生图形：

    package demo.panel;import java.util.HashMap;import java.util.Map;public class ShapeFactory {	public static final int SHAPE_CIRCLE = 0;	public static final int SHAPE_RECTANGLE = 1;	public static Map
    
      shapeMap = new HashMap
     
      (); 	static{		shapeMap.put(new Integer(SHAPE_CIRCLE), "Circle");		shapeMap.put(new Integer(SHAPE_RECTANGLE), "Rectangle");	}	public static Shape getShape(int shapeType){		String className = shapeMap.get(new Integer(shapeType));		if(className==null) return null;		try {			return (Shape)Class.forName(className).newInstance();		} catch (Exception e) {			return null;		} 	}}package demo.panel;import java.io.BufferedReader;import java.io.InputStreamReader;public class Panel {	public void selectShape(int shape){		Shape sh=ShapeFactory.getShape(shape);		if(sh==null){			System.out.println("your input shaple is not find!");		}else{			sh.draw();		}	}	public static void main(String[] args) throws Exception {		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));		int shapeType =  Integer.parseInt(br.readLine());	    Panel panel  = new Panel();	    panel.selectShape(shapeType);	}}耦合性最好的：把图形放到配置文件中配置文件：0=Circle             1=Rectangle