In software engineering, the singleton pattern is a software design pattern that restricts the instantiation of a class to one object. This is useful when exactly one object is needed to coordinate actions across the system. The concept is sometimes generalized to systems that operate more effici...
JEP 181 Nest-Based Acess Control 这一提案是为了增强自Java 1.1即引入的嵌套类设计。 嵌套类主要有两个用处。 第一是因为其只使用于很短的代码块中,在Java8之前,这主要依靠实现一个匿名类来完成。Java8之后,这种用法可以被lambda表达取代。 另一种用法是因为需要访问另一个类的内部。嵌套类具有和成员变量以及成员...