public abstract class Graphics_List {
public abstract void print(int cod);
public abstract void add();
public abstract void delete();
public abstract int getCount();
}
GraphicsListIn文件: //简单工程方法,将图形列表类包含的图形可以 扩展
public interface GraphicsListIn{
public String draw();
}
class Round implements GraphicsListIn{
public String draw(){
return "我是一个园";
}
}
class Triangle implements GraphicsListIn{
public String draw()
{
return "我是一个三角形";
}
}
class Rectangular implements GraphicsListIn{
public String draw()
{
return "我是一个矩形";
}
}
class Drawer{
public static GraphicsListIn drawGraphics(String s) throws Exception{
if(s.equalsIgnoreCase("Round"))
{
return new Round();
}
else if(s.equalsIgnoreCase("Triangle"))
{
return new Triangle();
}
else if(s.equalsIgnoreCase("Rectangular"))
{
return new Rectangular();
}
else throw new Exception();
}
}