讨论那些由java.lang定义的类和接口。正如你所知道的那样，java.lang被自动导入所有的程序。它所包含的类和接口对所有实际的Java程序都是必要的。它是Java最广泛使用的包。-Discuss those defined by the java.lang classes and interfaces. As you know it, java.lang is automatically imported all of the procedures. It contains classes and interfaces for all the actual Java programs are necessary. It is the most widely used Java packages.