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设计模式-享元模式

news 2025/7/3 16:18:03

一、用到的类

一个接口
一个接口实现类
一个享元工厂：里面有一个用于存储实现类的map，key为我们随机指定的（我们自己是知道的，以后会用这个key去获取），还有一个获取对象方法，先去map中找，找不到就创建并塞入map，找到了就返回

二、实现代码

接口代码

public interface Shape {void draw();
}

接口实现代码

public class Circle implements Shape{private String color;public Circle(String color) {this.color = color;}@Overridepublic void draw() {System.out.println("画一个圆形:"+ color);}
}

享元工厂

public class FlyweighFactory {private static final Map<String,Shape> circleMap = new HashMap<>();public Shape getCircle(String color){Shape circle = circleMap.get(color);if(circle == null){circle = new Circle(color);circleMap.put(color, circle);System.out.println("创建了" + color + "的圆形");}return circle;}
}

调用类

@SpringBootApplication
public class FlyweighApplication {public static void main(String[] args) {FlyweighFactory flyweighFactory = new FlyweighFactory();Shape circle = flyweighFactory.getCircle("red");circle.draw();Shape circle1 = flyweighFactory.getCircle("yellow");circle1.draw();Shape circle2 = flyweighFactory.getCircle("blue");circle2.draw();}
}