Spring Boot @Autowired custom application.properties

Question

i am trying to get my custon application.properties fields working within a kotlin spring boot application.

My Current Setup:

ApplicationProperties.kt:

@Configuration
@ConfigurationProperties("mt")
class ApplicationProperties {

    var initDatabase: Boolean? = null
    val kafka = Kafka()

    class Kafka {
        lateinit var host: String
        lateinit var port: String
    }
}

application.properties:

mt.kafka.host=localhost
mt.kafka.port=9092
mt.init-database=true

And a class where i want to use my application: InitApp.kt

@Component
@EnableTransactionManagement
@EnableConfigurationProperties(ApplicationProperties::class)
class InitApp {
    @Autowired
    lateinit var conf: ApplicationProperties

    @Bean
    fun createKafkaConsumer() {
        log.info("${conf.kafka.host}")
    }
}

Sadly this doesn't work because i get a:

Caused by: kotlin.UninitializedPropertyAccessException: lateinit property conf has not been initialized

I followed this "guide" Bootiful Kotlin by Sébastien Deleuze and Josh Long @ Spring I/O 2018 and i am using these versions:

    kotlinVersion = '1.2.51'
    springBootVersion = '2.0.5.RELEASE'

apply plugin: 'kotlin-kapt' is in my build.gradle, but this should not mess with the @Autowired since, as far as i understood, it is for autocompletion in my application.properties.

Update 1:

I had a look at: Building web applications with Spring Boot and Kotlin and added the @EnableConfigurationProperties at Application level. This didn't work either

Update 2:

Full stacktrace:

2018-10-10 16:17:53.058 ERROR 23619 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'producerFactory' defined in class path resource [de/mikatiming/de/test/InitApp.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.kafka.core.ProducerFactory]: Factory method 'producerFactory' threw exception; nested exception is kotlin.UninitializedPropertyAccessException: lateinit property applicationProperties has not been initialized
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:590) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1247) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1096) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:535) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:759) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:780) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:333) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1277) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1265) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at de.mikatiming.de.test.TestApplicationKt.main(TestApplication.kt:15) [main/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_172]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_172]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_172]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_172]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.0.5.RELEASE.jar:2.0.5.RELEASE]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.kafka.core.ProducerFactory]: Factory method 'producerFactory' threw exception; nested exception is kotlin.UninitializedPropertyAccessException: lateinit property applicationProperties has not been initialized
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:582) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
... 23 common frames omitted
Caused by: kotlin.UninitializedPropertyAccessException: lateinit property applicationProperties has not been initialized
at de.mikatiming.de.test.InitApp.getApplicationProperties(InitApp.kt:36) ~[main/:na]
at de.mikatiming.de.test.InitApp.producerFactory(InitApp.kt:58) ~[main/:na]
at de.mikatiming.de.test.InitApp$$EnhancerBySpringCGLIB$$c3b698bb.CGLIB$producerFactory$10(<generated>) ~[main/:na]
at de.mikatiming.de.test.InitApp$$EnhancerBySpringCGLIB$$c3b698bb$$FastClassBySpringCGLIB$$b315799f.invoke(<generated>) ~[main/:na]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:365) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at de.mikatiming.de.test.InitApp$$EnhancerBySpringCGLIB$$c3b698bb.producerFactory(<generated>) ~[main/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_172]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_172]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_172]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_172]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.0.9.RELEASE.jar:5.0.9.RELEASE]
... 24 common frames omitted

Update 3:

I just found out that when i remove a specific bean from my InitApp:

@Bean
fun placeHolderConfigurer(): PropertySourcesPlaceholderConfigurer {
    return PropertySourcesPlaceholderConfigurer()
}

i get an other error message:

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'de.mikatiming.messageengine.configuration.ApplicationProperties' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

So it looks like it is an issue with this bean!

Answer 1

I managed to get it working:

Annotations

@Service
@Configuration
@EnableConfigurationProperties
@EnableTransactionManagement
class AppConfig {

ApplicationProperties:

@ConfigurationProperties("mt")
class ApplicationProperties {

ApplicationClass:

@SpringBootApplication
@EnableConfigurationProperties(ApplicationProperties::class)
abstract class MessageengineApplication

Beans

i needed to remove the following Bean from AppConfig:

@Bean
fun placeHolderConfigurer(): PropertySourcesPlaceholderConfigurer {
    return PropertySourcesPlaceholderConfigurer()
}