程序包 org.springframework.boot.autoconfigure.condition

批注接口 ConditionalOnSingleCandidate

@Target({TYPE,METHOD})
@Retention(RUNTIME)
@Documented
@Conditional(org.springframework.boot.autoconfigure.condition.OnBeanCondition.class)
public @interface ConditionalOnSingleCandidate

@Conditional that only matches when a bean of the specified class is already contained in the BeanFactory and a single candidate can be determined.

The condition will also match if multiple matching bean instances are already contained in the BeanFactory but a primary candidate has been defined; essentially, the condition match if auto-wiring a bean with the defined type will succeed.

The condition can only match the bean definitions that have been processed by the application context so far and, as such, it is strongly recommended to use this condition on auto-configuration classes only. If a candidate bean may be created by another auto-configuration, make sure that the one using this condition runs after.

从以下版本开始:

1.3.0

作者:

Stephane Nicoll

可选元素概要

可选元素

修饰符和类型	可选元素	说明
SearchStrategy	search	Strategy to decide if the application context hierarchy (parent contexts) should be considered.
String	type	The class type name of bean that should be checked.
Class<?>	value	The class type of bean that should be checked.

元素详细资料

value

Class<?> value

The class type of bean that should be checked. The condition matches if a bean of the class specified is contained in the BeanFactory and a primary candidate exists in case of multiple instances. Beans that are not autowire candidates, that are not default candidates, or that are fallback candidates are ignored.

This attribute may not be used in conjunction with type(), but it may be used instead of type().

返回:

the class type of the bean to check

另请参阅:

• Bean.autowireCandidate()
• BeanDefinition.isAutowireCandidate()
• Bean.defaultCandidate()
• AbstractBeanDefinition.isDefaultCandidate()

默认值:

java.lang.Object.class

type

String type

The class type name of bean that should be checked. The condition matches if a bean of the class specified is contained in the BeanFactory and a primary candidate exists in case of multiple instances. Beans that are not autowire candidates, that are not default candidates, or that are fallback candidates are ignored.

This attribute may not be used in conjunction with value(), but it may be used instead of value().

返回:

the class type name of the bean to check

另请参阅:

• Bean.autowireCandidate()
• BeanDefinition.isAutowireCandidate()
• Bean.defaultCandidate()
• AbstractBeanDefinition.isDefaultCandidate()

默认值:

""

search

SearchStrategy search

Strategy to decide if the application context hierarchy (parent contexts) should be considered.

返回:

the search strategy

默认值:

ALL