[转载]简单工厂创建不同几何图形（Java代码实例）

使用简单工厂模式设计一个可以创建不同几何图形（Shape），如Circle，Rectangle，Triangle等绘图工具类，每个几何图形均具有绘制Draw()和擦除Erase()两个方法；要求在绘制不支持的几何图形时，抛出一个UnsuppShapeException异常，绘制类图并使用Java语言实现。

/** * Description: 抽象产品角色 */ 
public abstract class Shape { public abstract void draw(); public abstract void erase(); 
}/** * Description: 具体产品角色 */
public class Round extends Shape { @Override public void draw() { System.out.println("绘制圆形"); } @Override public void erase() { System.out.println("擦除圆形"); } 
} 
public class Square extends Shape { @Override public void draw() { System.out.println("绘制方形"); } @Override public void erase() { System.out.println("擦除方形"); } 
} 
public class Triangle extends Shape { @Override public void draw() { System.out.println("绘制三角形"); } @Override public void erase() { System.out.println("擦除三角形"); } 
}/** * Description: 工厂角色 */ 
public class ShapeFactory { // 声明创建形状的静态工厂方法 public static Shape createShape(String type) throws UnSupportedShapeException { Shape shape; if ("圆形".equals(type)) { shape = new Round(); } else if ("方形".equals(type)) {shape = new Square(); } else if ("三角形".equals(type)) { shape = new Triangle(); } else { throw new UnSupportedShapeException("UnSupportedShapeException"); } return shape;} 
} /** * Description: 自定义异常 */ 
public class UnSupportedShapeException extends Exception { public UnSupportedShapeException(String message) { super(message); } 
}/** * Description: 客户端 */ 
public class DrawingTool { public static void main(String[] args) { Shape s1, s2, s3, s4; try { s1 = ShapeFactory.createShape("圆形"); s2 = ShapeFactory.createShape("方形"); s3 = ShapeFactory.createShape("三角形"); s1.draw(); s1.erase(); s2.draw(); s2.erase(); s3.draw(); s3.erase(); // s4.draw(); // s4.erase(); } catch (Exception e) { System.out.println(e.getMessage()); } } 
}