Spring boot version: 3.2.2

Scenario: Even though my application.properties did have power.level property, but the bean is still created, which should not be the case, given the matchIfMissing being set to true. Is this a bug?

@AutoConfiguration
public class SuperHeroConfig {

    @Bean
    @ConditionalOnProperty(name = "power.level",matchIfMissing = true)
    public String powerLevel(){
        return "0";
    }
}

Below is application.properties

power.level=3

Comment From: wilkinsona

No, this is the expected behavior. You have not set havingValue so its default behavior applies:

The string representation of the expected value for the properties. If not specified, the property must not be equal to false

Combined with matchIfMissing = true this means that the condition will match if power.level is missing or it has a value other than false. In other words matchIfMissing = true applies in addition to havingValue not instead of it.

Comment From: hannah23280

Thanks for the resposne. Just to ensure my understanding of your response is correct Below configuration will create the powerLevel Bean, since power.level=0 is missing

@AutoConfiguration
public class SuperHeroConfig {


    @Bean
    @ConditionalOnProperty(prefix="power", name = "level",matchIfMissing = true, havingValue = "0")
    public String powerLevel(){
        return "0";
    }
}

Application.properties

power.level=1

Comment From: wilkinsona

It will not match because power.level has a value of 1 when it's required to be 0. It will also match if power.level hasn't been set at all as you have set matchIfMissing to true.

If you have any further questions, please follow up on Stack Overflow. As mentioned in the guidelines for contributing, we prefer to use GitHub issues only for bugs and enhancements.

Comment From: hannah23280

It will match because power.level has a value of 1 when it's required to be 0. It will also match if power.level hasn't been set at all as you have set matchIfMissing to true.

If you have any further questions, please follow up on Stack Overflow. As mentioned in the guidelines for contributing, we prefer to use GitHub issues only for bugs and enhancements.

Thanks. When i tested it out and observe the following:

If power.level is not set, it matches as per your explanation. If power.level is set to 1, it does not match , which is different from your explanation. So not sure if any possibility of bug?

Comment From: wilkinsona

Sorry. There was a typo in my comment which I have now corrected. It will not match because power.level has a value of 1 when it's required to be 0.

Comment From: hannah23280

Sorry. There was a typo in my comment which I have now corrected. It will not match because power.level has a value of 1 when it's required to be 0.

Thank you. Now i begin to understand what happen. 

@ConditionalOnProperty(prefix="power", name = "level",matchIfMissing = true, havingValue = "0")

This means it match if either of the below criteria is satisfied 1) power.level = 0, OR 2) power.level is missing