SpringBoot @ConditionalOnProperty 复杂场景应用

最近在开发 spring-boot-starter时涉及到多个条件进行 OR 逻辑运算，而ConditionalOnProperty默认是支持 “多个条件逻辑” AND运算；

例如：

@ConditionalOnProperty(name={"app.initialize.dictionary","app.initialize.all"}, havingValue="true")

这显然不符合我们的要求，我们需要“逻辑或”

解决方案有2个：

一种繁琐的做法，是自定义条件，继承AnyNestedCondition
还有一种比较灵活的方式是使用@ConditionalOnExpression写一个SpEL表达式

方案一

class DicOrAllCondition extends AnyNestedCondition {

    public DicOrAllCondition() {
        super(ConfigurationPhase.PARSE_CONFIGURATION);
    }

    @ConditionalOnProperty(name = "app.initialize.dictionary", value = "true")
    static class DicCondition {
    }

    @ConditionalOnProperty(name = "app.initialize.all", value = "true")
    static class AllCondition {
    }
}

用法：

@Order(1)
@Component
@Conditional(DicOrAllCondition.class)
public class DictionaryInitializer implements CommandLineRunner{

}

方案二

@Order(1)
@Component
@ConditionalOnExpression("${app.initialize.dictionary:false} || ${app.initialize.all:false}")
public class DictionaryInitializer implements CommandLineRunner{

}

application.properties如下：

app.initialize.all=true
app.initialize.dictionary=false

还有更灵活的配置方式：

@ConditionalOnExpression("${app.initialize.dictionary:${app.initialize.all:false}}")

TFdream / blog

SpringBoot @ConditionalOnProperty 复杂场景应用 #409