A second advantage of static factory methods is that, unlike constructors, they are not required to create a new object each time they're invoked.
A second advantage of static factory methods is that, unlike constructors, they are not required to create a new object each time they're invoked.
第二个好处是，与构造函数不同，它们每次被调用的时候，不要求非得创建一个新的对象。