程序包 cn.taketoday.context.annotation

Annotation Interface Conditional

@Documented @Retention(RUNTIME) @Target({TYPE,METHOD}) public @interface Conditional
Indicates that a component is only eligible for registration when all specified conditions match.

A condition is any state that can be determined programmatically before the bean definition is due to be registered (see Condition for details).

The @Conditional annotation may be used in any of the following ways:

  • as a type-level annotation on any class directly or indirectly annotated with @Component, including @Configuration classes
  • as a meta-annotation, for the purpose of composing custom stereotype annotations
  • as a method-level annotation on any @Bean method

If a @Configuration class is marked with @Conditional, all of the @Bean methods, @Import annotations, and @ComponentScan annotations associated with that class will be subject to the conditions.

NOTE: Inheritance of @Conditional annotations is not supported; any conditions from superclasses or from overridden methods will not be considered. In order to enforce these semantics, @Conditional itself is not declared as @Inherited; furthermore, any custom composed annotation that is meta-annotated with @Conditional must not be declared as @Inherited.

从以下版本开始:
2018-11-14 18:50
作者:
Phillip Webb, Sam Brannen, TODAY
另请参阅:

  • 必需元素概要

    所需元素
    修饰符和类型
    必需的元素
    说明
    Class<? extends Condition>[]
    value
    All Conditions that must match in order for the component to be registered.