tracer.java

接着上次传入一些Java学习中的实验

 interface Shape{
	void draw();
	void erase();
	}
 class Square implements Shape{
	public void draw(){
	System.out.println("Square.draw()");
			}
	public void erase(){
	System.out.println("Square.erase()");
	}
}
 class Circle implements Shape{
	public void draw(){
	System.out.println("Circle.draw()");
		         }
	public void erase(){
	System.out.println("Circle.erase()");
		    }
    } 	
public class ArtTrace{
	public static Shape factory(String which)throws BadShapeException{
		if(which.equalsIgnoreCase("Circl")){	
			return new Circle();
		}else if(which.equalsIgnoreCasse("")){
		return new Square();
		}else if(which.equalsIgnoreCase("")){
		return new Triangle();
		}else{
		throw new BadShapeException(which);
     		 }
	         }
	}
 class Triangle implements Shape{
	public void draw(){
	System.out.println("Triange.draw()");
	}
	public void erase(){
	System.out.println("Triangle.erase()");
	
  }
 class BadShapeException extends Exception{
	public BadShapeException(String msg){
	super(msg);
	}
}
}
class use_implements{
public void use(){
	try{
	ArtTracer art=new ArtTracer();
	art.factory("Circle");	
	art.factory("Squale");
	art.factory("Triangle");
	art.factory("Diamond");
     }catch(BadShapeException e){
System.out.println("did not exist the shape what you want draw");
}
}
public static void main(String args[]){

    use_implements user=new use_implements();
	user.use();
	}
}