Kotlin + Spring Boot, cannot find beans

Question

I've just started to learn Kotlin and Spring Boot and I've done my implementation based on the online tutorial. But it failed to run and printed something like this:

Description:

Parameter 0 of constructor in com.jacksonhu.slientshare.controller.ForumController required a bean of type 'com.jacksonhu.slientshare.repository.ArticleRepo' that could not be found.


Action:

Consider defining a bean of type 'com.jacksonhu.slientshare.repository.ArticleRepo' in your configuration.

So I googled around and found some workaround topics. So I added a line of annotation @EnableJpaRepositories(basePackages = ["com.jacksonhu.slientshare.repository"]) below the @SpringBootApplication. Then a new exception thrown:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'forumController' defined in file [/Users/hu/Projects/SlientShare/out/production/classes/com/jacksonhu/slientshare/controller/ForumController.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'articleRepo': Post-processing of merged bean definition failed; nested exception is java.lang.NoClassDefFoundError: javax/persistence/SynchronizationType
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:729) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:192) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1270) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1127) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:541) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.1.RELEASE.jar:2.0.1.RELEASE]
    at com.jacksonhu.slientshare.SlientshareApplicationKt.main(SlientshareApplication.kt:19) [classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'articleRepo': Post-processing of merged bean definition failed; nested exception is java.lang.NoClassDefFoundError: javax/persistence/SynchronizationType
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:501) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:815) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:721) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    ... 18 common frames omitted
Caused by: java.lang.NoClassDefFoundError: javax/persistence/SynchronizationType
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.<init>(PersistenceAnnotationBeanPostProcessor.java:653) ~[spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.lambda$buildPersistenceMetadata$1(PersistenceAnnotationBeanPostProcessor.java:435) ~[spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.util.ReflectionUtils.doWithLocalMethods(ReflectionUtils.java:522) ~[spring-core-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.buildPersistenceMetadata(PersistenceAnnotationBeanPostProcessor.java:420) ~[spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.findPersistenceMetadata(PersistenceAnnotationBeanPostProcessor.java:394) ~[spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(PersistenceAnnotationBeanPostProcessor.java:332) ~[spring-orm-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:1016) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
    ... 28 common frames omitted
Caused by: java.lang.ClassNotFoundException: javax.persistence.SynchronizationType
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_161]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_161]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338) ~[na:1.8.0_161]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_161]
    ... 36 common frames omitted

So I just wondering if I have misunderstood something? Or my configuration was wrong?

My gradle configuration is here:

buildscript {
    ext {
        kotlinVersion = '1.2.40'
        springBootVersion = '2.0.1.RELEASE'
    }
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}")
        classpath("org.jetbrains.kotlin:kotlin-allopen:${kotlinVersion}")
    }
}

apply plugin: 'kotlin'
apply plugin: 'kotlin-spring'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'

group = 'com.jacksonhu'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
compileKotlin {
    kotlinOptions {
        freeCompilerArgs = ["-Xjsr305=strict"]
        jvmTarget = "1.8"
    }
}
compileTestKotlin {
    kotlinOptions {
        freeCompilerArgs = ["-Xjsr305=strict"]
        jvmTarget = "1.8"
    }
}

repositories {
    mavenCentral()
}


dependencies {
    compile('org.springframework.boot:spring-boot-starter-security')
    compile("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
    compile("org.jetbrains.kotlin:kotlin-reflect")
    compile group: 'javax.persistence', name: 'persistence-api', version: '1.0'
    compile group: 'org.springframework.data', name: 'spring-data-jpa', version: '2.0.6.RELEASE'
    compile group: 'javax.validation', name: 'validation-api', version: '2.0.1.Final'
    runtime('mysql:mysql-connector-java')
    testCompile('org.springframework.boot:spring-boot-starter-test')
    testCompile('org.springframework.security:spring-security-test')
}

...and my main class:

package com.jacksonhu.slientshare

import org.springframework.boot.SpringApplication

import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
import org.springframework.context.annotation.ComponentScan
import org.springframework.data.jpa.repository.config.EnableJpaRepositories

@SpringBootApplication
@ComponentScan(basePackages = ["com.jacksonhu.slientshare"])
@EnableJpaRepositories(basePackages = ["com.jacksonhu.slientshare.repository"])
class SlientshareApplication

fun main(args: Array<String>) {
    runApplication<SlientshareApplication>(*args)
}

...and the whole package structure:

In case someone need to review my code, here it is: https://github.com/huming2207/SlientShare

Answer 1

You missed some dependencies:

dependencies {
    compile('org.springframework.boot:spring-boot-starter-web')
    compile('org.springframework.boot:spring-boot-starter-security')
    compile('org.springframework.boot:spring-boot-starter-data-jpa')

    compile("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
    compile("org.jetbrains.kotlin:kotlin-reflect")

    compile group: 'javax.xml.bind', name: 'jaxb-api', version: '2.3.0'
    compile group: 'org.hibernate.javax.persistence', name: 'hibernate-jpa-2.1-api', version: '1.0.2.Final'
    compile group: 'javax.validation', name: 'validation-api', version: '2.0.1.Final'
    runtime('mysql:mysql-connector-java')
    testCompile('org.springframework.boot:spring-boot-starter-test')
    testCompile('org.springframework.security:spring-security-test')
}

; I cloned your code from GitHub, after adding this dependency, it works.