求更简洁的代码

package Chapter5;
import java.util.Scanner;
abstract class Shape1{
	public abstract void Sum();	
	public abstract void Area();
	} 
class Rectang extends Shape1{	 
     double width;	  
     double length;	  
 public Rectang(){		 
  	  }	
 public Rectang(double width,double length){	
 	  this.width=width;	
 	  this.length=length;	 
 	   }	   
 public  void Sum(){	    	
       double sum=2*(width+length);	    
       System.out.println("长方形周长为："+sum);	
           }		
 public  void Area(){			
       double sum=width*length;			
       System.out.println("长方形面积为："+sum);		
       } 
   } 
class Circle extends Shape1{	 
      double radius;	 
      public Circle(){		  
      	  }	 
      public Circle(double radius){	
      	  this.radius=radius;		  
      	  }	   
      public  void Sum(){	   
       	double sum=Math.PI*2*radius;	    
        System.out.println("圆的周长为："+sum);	  
          }		
      public  void Area(){		
     	double sum=Math.PI*radius*radius;		
        System.out.println("圆的面积为："+sum);		
        }
        }
    public class Shape_1 {	
         public static void main(String[] args) {		
         // TODO Auto-generated method stub		
         boolean dd=true;       
         Scanner in=new Scanner(System.in);      
          while(dd){       
           System.out.println("请选择你要计算的图形：1--长方形,2--圆:");    
           int s=in.nextInt();      
           if(s==1){    	   
           System.out.println("请输入长方形的宽：");    	
           int aa=in.nextInt();    	   
           System.out.println("请输入长方形的长：");    	  
           int ss=in.nextInt();    	  
           Shape1 sh;    	  
           sh=new Rectang(aa,ss);    	 
             sh.Sum();    	   
             sh.Area();    	   
             dd=false;       
             }
           else if(s==2){    	  
           System.out.println("请输入圆的半径：");    
           int aa=in.nextInt();    	   
           Shape1 sh;    	   
           sh=new Circle(aa);    	   
           sh.Sum();    	   
           sh.Area();    	   
           dd=false;       
           }else{    	  
           System.out.println("你输入的有误请重新输入");     	  
           dd=true;       
           }       
          }	
         }
     }