ConditionalOnBean：当容器里有指定的bean的条件下
ConditionalOnClass：当类路径下有指定的类的条件下
ConditionalOnExpression: 基于SpEL表达式作为判断条件
ConditionalOnJava:基于java版本作为判断条件
ConditionalOnJndi：在JNDI存在的条件下查找指定的位置
ConditionalOnMissingBean :当容器里没有指定的bean的情况下
ConditionalOnMissingClass: 当容器没有指定的类的情况下
ConditionalOnNoWenApplication：当前项目不是web项目的条件下
ConditionalOnProperty:指定的属性是否有指定的值
ConditionalOnResource：类路径是否有指定的值
ConditionalOnSingleCandidate：当指定的bean在容器中只有一个，或者虽然有多个但是指定首选bean
ConditionalOnWebApplication：当前项目是web项目的条件下自动配置类必须在一定条件下才会生效。都通过@Conditional注解标签来配置实现。
我们可以通过启用配置属性debug=true，来使项目启动时，自动在控制台输出自动匹配报告。
Positive matches:（启用的自动配置类）
-----------------CodecsAutoConfiguration matched:- @ConditionalOnClass found required class 'org.springframework.http.codec.CodecConfigurer' (OnClassCondition)CodecsAutoConfiguration.JacksonCodecConfiguration matched:- @ConditionalOnClass found required class 'com.fasterxml.jackson.databind.ObjectMapper' (OnClassCondition)CodecsAutoConfiguration.JacksonCodecConfiguration#jacksonCodecCustomizer matched:- @ConditionalOnBean (types: com.fasterxml.jackson.databind.ObjectMapper; SearchStrategy: all) found bean 'jacksonObjectMapper' (OnBeanCondition)DispatcherServletAutoConfiguration matched:- @ConditionalOnClass found required class 'org.springframework.web.servlet.DispatcherServlet' (OnClassCondition)- found 'session' scope (OnWebApplicationCondition)
.....Negative matches:（没有启用的自动配置类）
-----------------ActiveMQAutoConfiguration:Did not match:- @ConditionalOnClass did not find required class 'javax.jms.ConnectionFactory' (OnClassCondition)AopAutoConfiguration:Did not match:- @ConditionalOnClass did not find required class 'org.aspectj.lang.annotation.Aspect' (OnClassCondition)ArtemisAutoConfiguration:Did not match:- @ConditionalOnClass did not find required class 'javax.jms.ConnectionFactory' (OnClassCondition)
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