Spark 公共篇-InterfaceStability

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。

参考文献：

• hadoop 基本注解： InterfaceAudience InterfaceStability

• hadoop 注解之 interfaceAudience interfaceStability