本章内容：
1、源码
InterfaceStability 类包含三个注解，用于说明被他们注解的类型的稳定性。
/**
* Annotation to inform users of how much to rely on a particular package,
* class or method not changing over time.
*/
public class InterfaceStability {
/**
* Stable APIs that retain source and binary compatibility within a major release.
* These interfaces can change from one major release to another major release
* (e.g. from 1.0 to 2.0).
*/
@Documented
public @interface Stable {};
/**
* APIs that are meant to evolve towards becoming stable APIs, but are not stable APIs yet.
* Evolving interfaces can change from one feature release to another release (i.e. 2.1 to 2.2).
*/
@Documented
public @interface Evolving {};
/**
* Unstable APIs, with no guarantee on stability.
* Classes that are unannotated are considered Unstable.
*/
@Documented
public @interface Unstable {};
}
2、总结
InterfaceStability 类包含三个注解，用于说明被他们注解的类型的稳定性。
@InterfaceStability.Stable： 说明主版本是稳定的，不同主版本之间可能不兼容。
@InterfaceStability.Evolving： 说明是不停在变化的，不同小版本之间也可能不兼容。
@InterfaceStability.Unstable： 说明稳定性没有任何保证。