Error running Spring boot quickstart project

Question

I am configuring a basic spring boot program as mentioned on its website, but I am getting the following error :

C:\Users\destin\OneDrive\Documents\jdk-11.0.10\bin\java.exe "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.2.3\lib\idea_rt.jar=52872:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.2.3\bin" -Dfile.encoding=UTF-8 -classpath C:\D-drive\codage-aider\student\destin\enterprise\target\classes;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-starter-web\2.6.1\spring-boot-starter-web-2.6.1.jar;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-starter\2.6.1\spring-boot-starter-2.6.1.jar;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot\2.6.1\spring-boot-2.6.1.jar;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.6.1\spring-boot-autoconfigure-2.6.1.jar;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-starter-logging\2.6.1\spring-boot-starter-logging-2.6.1.jar;C:\Users\destin\.m2\repository\ch\qos\logback\logback-classic\1.2.7\logback-classic-1.2.7.jar;C:\Users\destin\.m2\repository\ch\qos\logback\logback-core\1.2.7\logback-core-1.2.7.jar;C:\Users\destin\.m2\repository\org\apache\logging\log4j\log4j-to-slf4j\2.14.1\log4j-to-slf4j-2.14.1.jar;C:\Users\destin\.m2\repository\org\apache\logging\log4j\log4j-api\2.14.1\log4j-api-2.14.1.jar;C:\Users\destin\.m2\repository\org\slf4j\jul-to-slf4j\1.7.32\jul-to-slf4j-1.7.32.jar;C:\Users\destin\.m2\repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;C:\Users\destin\.m2\repository\org\yaml\snakeyaml\1.29\snakeyaml-1.29.jar;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-starter-json\2.6.1\spring-boot-starter-json-2.6.1.jar;C:\Users\destin\.m2\repository\com\fasterxml\jackson\core\jackson-databind\2.13.0\jackson-databind-2.13.0.jar;C:\Users\destin\.m2\repository\com\fasterxml\jackson\core\jackson-annotations\2.13.0\jackson-annotations-2.13.0.jar;C:\Users\destin\.m2\repository\com\fasterxml\jackson\core\jackson-core\2.13.0\jackson-core-2.13.0.jar;C:\Users\destin\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.13.0\jackson-datatype-jdk8-2.13.0.jar;C:\Users\destin\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.13.0\jackson-datatype-jsr310-2.13.0.jar;C:\Users\destin\.m2\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.13.0\jackson-module-parameter-names-2.13.0.jar;C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-starter-tomcat\2.6.1\spring-boot-starter-tomcat-2.6.1.jar;C:\Users\destin\.m2\repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.55\tomcat-embed-core-9.0.55.jar;C:\Users\destin\.m2\repository\org\apache\tomcat\embed\tomcat-embed-el\9.0.55\tomcat-embed-el-9.0.55.jar;C:\Users\destin\.m2\repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.55\tomcat-embed-websocket-9.0.55.jar;C:\Users\destin\.m2\repository\org\springframework\spring-web\5.3.13\spring-web-5.3.13.jar;C:\Users\destin\.m2\repository\org\springframework\spring-beans\5.3.13\spring-beans-5.3.13.jar;C:\Users\destin\.m2\repository\org\springframework\spring-webmvc\5.3.13\spring-webmvc-5.3.13.jar;C:\Users\destin\.m2\repository\org\springframework\spring-aop\5.3.13\spring-aop-5.3.13.jar;C:\Users\destin\.m2\repository\org\springframework\spring-context\5.3.13\spring-context-5.3.13.jar;C:\Users\destin\.m2\repository\org\springframework\spring-expression\5.3.13\spring-expression-5.3.13.jar;C:\Users\destin\.m2\repository\org\slf4j\slf4j-api\1.7.32\slf4j-api-1.7.32.jar;C:\Users\destin\.m2\repository\org\springframework\spring-core\5.3.13\spring-core-5.3.13.jar;C:\Users\destin\.m2\repository\org\springframework\spring-jcl\5.3.13\spring-jcl-5.3.13.jar DemoApplication

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.6.1)

2021-12-10 22:51:06.592  INFO 24260 --- [           main] DemoApplication                          : Starting DemoApplication using Java 11.0.10 on DESKTOP-NHT8PTC with PID 24260 (C:\D-drive\codage-aider\student\destin\enterprise\target\classes started by destin in C:\D-drive\codage-aider\student\destin\enterprise)
2021-12-10 22:51:06.595  INFO 24260 --- [           main] DemoApplication                          : No active profile set, falling back to default profiles: default
2021-12-10 22:51:06.669  WARN 24260 --- [           main] ionWarningsApplicationContextInitializer : 

** WARNING **: Your ApplicationContext is unlikely to start due to a @ComponentScan of the default package.


2021-12-10 22:51:07.265  WARN 24260 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: URL [jar:file:C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.6.1\spring-boot-autoconfigure-2.6.1.jar!/org/springframework/boot/autoconfigure/r2dbc/ConnectionFactoryConfigurations$PoolConfiguration.class]; nested exception is java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$PoolConfiguration due to io/r2dbc/spi/ValidationDepth not found. Make sure your own configuration does not rely on that class. This can also happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
2021-12-10 22:51:07.272  INFO 24260 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-12-10 22:51:07.301 ERROR 24260 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: URL [jar:file:C:\Users\destin\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.6.1\spring-boot-autoconfigure-2.6.1.jar!/org/springframework/boot/autoconfigure/r2dbc/ConnectionFactoryConfigurations$PoolConfiguration.class]; nested exception is java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$PoolConfiguration due to io/r2dbc/spi/ValidationDepth not found. Make sure your own configuration does not rely on that class. This can also happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.scanCandidateComponents(ClassPathScanningCandidateComponentProvider.java:457) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:316) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ClassPathBeanDefinitionScanner.doScan(ClassPathBeanDefinitionScanner.java:276) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ComponentScanAnnotationParser.parse(ComponentScanAnnotationParser.java:128) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:296) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:250) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:207) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:175) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:331) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:247) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:311) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:112) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:746) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:564) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:730) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) ~[spring-boot-2.6.1.jar:2.6.1]
    at DemoApplication.main(DemoApplication.java:13) ~[classes/:na]
Caused by: java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$PoolConfiguration due to io/r2dbc/spi/ValidationDepth not found. Make sure your own configuration does not rely on that class. This can also happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
    at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:54) ~[spring-boot-autoconfigure-2.6.1.jar:2.6.1]
    at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:108) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:88) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:71) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.isConditionMatch(ClassPathScanningCandidateComponentProvider.java:512) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.isCandidateComponent(ClassPathScanningCandidateComponentProvider.java:495) ~[spring-context-5.3.13.jar:5.3.13]
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.scanCandidateComponents(ClassPathScanningCandidateComponentProvider.java:430) ~[spring-context-5.3.13.jar:5.3.13]
    ... 20 common frames omitted
Caused by: java.lang.NoClassDefFoundError: io/r2dbc/spi/ValidationDepth
    at java.base/java.lang.Class.getDeclaredMethods0(Native Method) ~[na:na]
    at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3166) ~[na:na]
    at java.base/java.lang.Class.getDeclaredMethods(Class.java:2309) ~[na:na]
    at org.springframework.boot.context.properties.bind.JavaBeanBinder$Bean.getSorted(JavaBeanBinder.java:140) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.JavaBeanBinder$Bean.addProperties(JavaBeanBinder.java:132) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.JavaBeanBinder$Bean.<init>(JavaBeanBinder.java:127) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.JavaBeanBinder$Bean.get(JavaBeanBinder.java:225) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:54) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.lambda$bindDataObject$5(Binder.java:473) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:587) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder$Context.withDataObject(Binder.java:573) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder$Context.access$300(Binder.java:534) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.bindDataObject(Binder.java:471) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:411) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:340) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:329) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:259) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:220) ~[spring-boot-2.6.1.jar:2.6.1]
    at org.springframework.boot.autoconfigure.r2dbc.ConnectionFactoryConfigurations$PooledConnectionFactoryCondition.getMatchOutcome(ConnectionFactoryConfigurations.java:138) ~[spring-boot-autoconfigure-2.6.1.jar:2.6.1]
    at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:47) ~[spring-boot-autoconfigure-2.6.1.jar:2.6.1]
    ... 26 common frames omitted
Caused by: java.lang.ClassNotFoundException: io.r2dbc.spi.ValidationDepth
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) ~[na:na]
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522) ~[na:na]
    ... 46 common frames omitted


Process finished with exit code 1

This is the pom.xml I am using :

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.3.4.RELEASE</version>
            </plugin>
        </plugins>
    </build>

</project>

and I have just put one file DemoApplication mentioned here - https://spring.io/quickstart
What could be the reason for this? Ideally, this should run as a starter project and shouldn't require anything else on my part. What could be the issue here?

Answer 1

Sometime this can happen when your application Where you have put the @SpringBootApplication annotation is in the default package under src/main/java folder. Try moving the class where you put @SpringBootApplication annotation is in a different package, say: sr/main/java/com/example/

Answer 2

try building the application under a different package, or adding @componentscan annotation on the application class to specify the package to scan

If you're new to spring boot... I get a little confused using Spring boot's documentation. But spring's documentaion is easier for me to follow. Additionally, there's a YT with decent spring info.

https://spring.io/guides/gs/spring-boot/

https://www.youtube.com/watch?v=9SGDpanrc8U&t=4039s