描述：蝇量模式，共享对象支持大量的细粒度对象，内/外部状态，共享/非共享
优点：减少对象创建，降低内存
缺点：外部状态不随内部改变，提高复杂性
应用：缓冲池，连接池，相似对象
classDiagram
class Flyweight {
<>
+doOperation(extrinsicState string)* void
}
class ConcreteFlyweight{
-intrinsicState : string
constructor(intrinsicState : string)
+doOperation(extrinsicState : string) void
}
class flyweightObject{
<>
[key : string] : Flyweight
}
class FlyweightFactory {
-flyweights : flyweightObject
constructor()
+getFlyweight(intrinsicState : string) Flyweight
}
Flyweight <|-- ConcreteFlyweight:继承
flyweightObject --o FlyweightFactory :聚合
Flyweight --o FlyweightFactory :聚合
- 抽象类，定义对象的内部，外部状态的接口
- 享元工厂，返回具体实现的产品类
- 实例话一个工厂，通过工厂获取抽象类的实现，并缓存这些实例，调用实例的方法，即类的公有方法
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| abstract class Flyweight {
public abstract doOperation(extrinsicState : string) : void;
}
class ConcreteFlyweight extends Flyweight {
private intrinsicState : string;
constructor(intrinsicState : string) {
super();
this.intrinsicState = intrinsicState;
}
public doOperation(extrinsicState : string) : void {
console.log(`这是具体享元角色，内部状态为${this.intrinsicState},外部状态为${extrinsicState}`);
}
}
interface flyweightObject {
[key : string] : Flyweight
}
class FlyweightFactory {
private flyweights : flyweightObject;
constructor() {
this.flyweights = {};
}
public getFlyweight(intrinsicState : string) : Flyweight {
if (!this.flyweights[intrinsicState]) {
const flyweight : Flyweight = new ConcreteFlyweight(intrinsicState);
this.flyweights[intrinsicState] = flyweight;
}
return this.flyweights[intrinsicState];
}
}
function main() {
const factory : FlyweightFactory = new FlyweightFactory();
const flyweight1 : Flyweight = factory.getFlyweight("aa");
const flyweight2 : Flyweight = factory.getFlyweight("aa");
flyweight1.doOperation('x');
flyweight2.doOperation('y');
}
main()
|
