org.springframework.beans.factory.annotation

## 注释类型 Qualifier

-     @Target(value={FIELD,METHOD,PARAMETER,TYPE,ANNOTATION_TYPE})
       @Retention(value=RUNTIME)
       @Inherited
       @Documented
      public @interface Qualifier

  This annotation may be used on a field or parameter as a qualifier for candidate beans when autowiring. It may also be used to annotate other custom annotations that can then in turn be used as qualifiers.
  从以下版本开始:
    2.5
  作者:
    Mark Fisher, Juergen Hoeller
  另请参阅:
    `Autowired`

- - ### 可选元素概要

    可选元素
    限定符和类型 | 可选元素和说明
    --- | ---
    `String` | `value`

- - ### 元素详细资料

    - #### value

          public abstract String value

      默认值:
        ""