public interface Color{
    
    public void display();

}

public Class Red implements Color{
    
    @Override
    public void display(){
       "我是紅色"; 
    }
}

public Class Blue implements Color{
    
    @Override
    public void display(){
       "我是藍色"; 
    }

}

public class SampleFactory {
    public static Color makeColor(String type){
        if("Red".equals(type)){
            Color color= new Red();
            return color;
        }else if("Blue".equals(type)){
            Color color= new Red();
            return color;
        }else{
            
            return null;
        }            
    }
}