spring - Spring Boot @Autowired 自定义 application.properties

Question

我正在尝试让我的 custon application.properties 字段在 kotlin spring boot 应用程序中工作。

我当前的设置：

应用程序属性.kt：

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

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

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

应用程序属性：

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

还有一个我想使用我的应用程序的类：InitApp.kt

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

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

可悲的是，这不起作用，因为我得到：

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

我遵循了 Sébastien Deleuze 和 Josh Long @ Spring I/O 2018 编写的 Bootiful Kotlin “指南” ，我正在使用这些版本：

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

apply plugin: 'kotlin-kapt'在我的 build.gradle 中，但这不应该与@Autowired因为据我所知，它是为了在我的 application.properties 中自动完成。

更新1：

我看了一下：使用 Spring Boot 和 Kotlin 构建 Web 应用程序并添加了@EnableConfigurationProperties应用程序级别。这也不起作用

更新 2：

完整的堆栈跟踪：

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

更新 3：

我刚刚发现，当我从 InitApp 中删除特定的 bean 时：

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

我收到另一条错误消息：

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)}

所以看起来这是这个bean的问题！

标签： springspring-bootkotlin

Answer 1

我设法让它工作：

注释

@Service
@Configuration
@EnableConfigurationProperties
@EnableTransactionManagement
class AppConfig {

应用程序属性：

@ConfigurationProperties("mt")
class ApplicationProperties {

应用类：

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

豆子

我需要从 AppConfig 中删除以下 Bean：

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