@ConfigurationProperties constructor binding not working in 2.2.0.RC1

[dldiehl77]

I created a very, very simple project to test out configuration properties constructor binding. It sure doesn't seem to work at all. I've attached a zip file with the little project.

I also created this on stackoverflow but didn't get much help there: https://stackoverflow.com/questions/58259065/configurationproperties-constructor-binding-not-working-in-2-2-0-rc1

In the attached project, if I remove the "final" keyword on the "stuff" field, uncomment the setter method, and comment out the single argument constructor, the project runs fine (the application starts and the framework calls the setter). I've also tried commenting out the @configuration annotation but that made no difference.

Anyway, when the application starts it fails with this error:

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of constructor in com.acme.AppConfig required a bean of type 'java.lang.String' that could not be found.


Action:

Consider defining a bean of type 'java.lang.String' in your configuration.

[dldiehl77]

spring-boot-acme.zip

Here is the sample project that fails to start.

[wilkinsona]

Thanks for the sample. To opt in to constructor binding of configuration properties, you should use @ImmutableConfigurationProperties as described in the documentation.

You should not use @Configuration on a configuration properties class. @Configuration should be used to indicate that the class provides bean definitions via @Bean. @ConfigurationProperties or @ImmutableConfigurationProperties is sufficient.

[wilkinsona]

I've opened #18545 to see if we can improve the failure analysis and the resulting error message.

[dldiehl77]

I see my primary mistake. I was reading old documentation: https://docs.spring.io/spring-boot/docs/2.2.0.M2/reference/html/spring-boot-features.html#boot-features-external-config-constructor-binding

The new RC1 documentation has been updated and has the ImmutableConfigurationProperties annotation on the example. One small suggestion though: since you have import statements on that example, include the import statement for the ImmutableConfigurationProperties as well.

[philwebb]

@dldiehl77 Thanks for raising that, I've opened #18547

[To-da]

I do believe it should be updated also for Kotlin example: https://docs.spring.io/spring-boot/docs/2.2.0.RC1/reference/htmlsingle/#boot-features-kotlin-configuration-properties

[wilkinsona]

Thank you, @To-da. I believe @sdeleuze has already taken care of that in #18573.

[perlun]

Old issue, but I'm running into some weird issues with Spring Boot v2.4.0. When following this approach (non-immutable @ConfigurationProperties), all works fine: https://docs.spring.io/spring-boot/docs/current/reference/html/features.html#features.external-config.typesafe-configuration-properties.java-bean-binding. I can look at the MyProperties instance in the debugger and I see that all values from application.yaml have been properly injected.

However, when I try the approach in https://docs.spring.io/spring-boot/docs/current/reference/html/features.html#features.external-config.typesafe-configuration-properties.constructor-binding, i.e. this definition of the MyProperties class instead:

@ConfigurationProperties("my.service")
public class MyProperties {

    // fields...

    private final boolean enabled;

    private final InetAddress remoteAddress;

    private final Security security;

    public MyProperties(boolean enabled, InetAddress remoteAddress, Security security) {
        this.enabled = enabled;
        this.remoteAddress = remoteAddress;
        this.security = security;
    }

    // getters...

    public boolean isEnabled() {
        return this.enabled;
    }

    public InetAddress getRemoteAddress() {
        return this.remoteAddress;
    }

    public Security getSecurity() {
        return this.security;
    }

    public static class Security {

        // fields...

        private final String username;

        private final String password;

        private final List<String> roles;

        public Security(String username, String password, @DefaultValue("USER") List<String> roles) {
            this.username = username;
            this.password = password;
            this.roles = roles;
        }

        // getters...

        public String getUsername() {
            return this.username;
        }

        public String getPassword() {
            return this.password;
        }

        public List<String> getRoles() {
            return this.roles;
        }

    }

}

...I get a NoSuchBeanDefinitionException like this:

org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'boolean' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1777) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1333) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:228) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1356) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1206) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:571) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1367) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:228) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1356) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1206) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:571) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.1.jar:5.3.1]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:925) ~[spring-context-5.3.1.jar:5.3.1]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588) ~[spring-context-5.3.1.jar:5.3.1]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.0.jar:2.4.0]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) ~[spring-boot-2.4.0.jar:2.4.0]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-2.4.0.jar:2.4.0]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) ~[spring-boot-2.4.0.jar:2.4.0]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) ~[spring-boot-2.4.0.jar:2.4.0]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1309) ~[spring-boot-2.4.0.jar:2.4.0]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1298) ~[spring-boot-2.4.0.jar:2.4.0]

The @ImmutableConfigurationProperties annotation seems to no longer exist in this version, likely because of #18563. I'll see if upgrading spring-boot to a later 2.x version might help...