Spring Boot Error related to

Question

Please help me in Spring Boot application,It does not work. I am so very nervous.

The folder list

Here is the codes:

1. App.java

import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication

@SpringBootApplication
public class App {

    public static void main(String[] args)
    {
        SpringApplication.run(App.class,args);
    }
}

2. MainController class:

   package Controllers;

   import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping;

   @Controller public class MainController {

   @RequestMapping("/")
   public String viewHome() {
       return "index";
   }
   

   }

And the error message:

/usr/lib/jvm/oracle-java8-jdk-amd64/bin/java -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=37934 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true -javaagent:/home/tozogabee/Downloads/idea-IU-171.4694.70/lib/idea_rt.jar=39375:/home/tozogabee/Downloads/idea-IU-171.4694.70/bin -Dfile.encoding=UTF-8 -classpath /usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/charsets.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/deploy.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/cldrdata.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/dnsns.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/jaccess.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/jfxrt.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/localedata.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/nashorn.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/sunec.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/sunjce_provider.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/sunpkcs11.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/ext/zipfs.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/javaws.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/jce.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/jfr.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/jfxswt.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/jsse.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/management-agent.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/plugin.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/resources.jar:/usr/lib/jvm/oracle-java8-jdk-amd64/jre/lib/rt.jar:/home/tozogabee/workspace/webapp/target/classes:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-starter/1.5.2.RELEASE/spring-boot-starter-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot/1.5.2.RELEASE/spring-boot-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/spring-context/4.3.7.RELEASE/spring-context-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/1.5.2.RELEASE/spring-boot-autoconfigure-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-starter-logging/1.5.2.RELEASE/spring-boot-starter-logging-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/ch/qos/logback/logback-classic/1.1.11/logback-classic-1.1.11.jar:/home/tozogabee/.m2/repository/ch/qos/logback/logback-core/1.1.11/logback-core-1.1.11.jar:/home/tozogabee/.m2/repository/org/slf4j/jcl-over-slf4j/1.7.24/jcl-over-slf4j-1.7.24.jar:/home/tozogabee/.m2/repository/org/slf4j/jul-to-slf4j/1.7.24/jul-to-slf4j-1.7.24.jar:/home/tozogabee/.m2/repository/org/slf4j/log4j-over-slf4j/1.7.24/log4j-over-slf4j-1.7.24.jar:/home/tozogabee/.m2/repository/org/springframework/spring-core/4.3.7.RELEASE/spring-core-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/yaml/snakeyaml/1.17/snakeyaml-1.17.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-starter-web/1.5.2.RELEASE/spring-boot-starter-web-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-starter-tomcat/1.5.2.RELEASE/spring-boot-starter-tomcat-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/8.5.11/tomcat-embed-core-8.5.11.jar:/home/tozogabee/.m2/repository/org/apache/tomcat/embed/tomcat-embed-el/8.5.11/tomcat-embed-el-8.5.11.jar:/home/tozogabee/.m2/repository/org/apache/tomcat/embed/tomcat-embed-websocket/8.5.11/tomcat-embed-websocket-8.5.11.jar:/home/tozogabee/.m2/repository/org/hibernate/hibernate-validator/5.3.4.Final/hibernate-validator-5.3.4.Final.jar:/home/tozogabee/.m2/repository/javax/validation/validation-api/1.1.0.Final/validation-api-1.1.0.Final.jar:/home/tozogabee/.m2/repository/org/jboss/logging/jboss-logging/3.3.0.Final/jboss-logging-3.3.0.Final.jar:/home/tozogabee/.m2/repository/com/fasterxml/classmate/1.3.3/classmate-1.3.3.jar:/home/tozogabee/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.8.7/jackson-databind-2.8.7.jar:/home/tozogabee/.m2/repository/com/fasterxml/jackson/core/jackson-annotations/2.8.0/jackson-annotations-2.8.0.jar:/home/tozogabee/.m2/repository/com/fasterxml/jackson/core/jackson-core/2.8.7/jackson-core-2.8.7.jar:/home/tozogabee/.m2/repository/org/springframework/spring-web/4.3.7.RELEASE/spring-web-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/spring-aop/4.3.7.RELEASE/spring-aop-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/spring-beans/4.3.7.RELEASE/spring-beans-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/spring-webmvc/4.3.7.RELEASE/spring-webmvc-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/spring-expression/4.3.7.RELEASE/spring-expression-4.3.7.RELEASE.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-starter-thymeleaf/1.5.2.RELEASE/spring-boot-starter-thymeleaf-1.5.2.RELEASE.jar:/home/tozogabee/.m2/repository/org/thymeleaf/thymeleaf-spring4/2.1.5.RELEASE/thymeleaf-spring4-2.1.5.RELEASE.jar:/home/tozogabee/.m2/repository/org/thymeleaf/thymeleaf/2.1.5.RELEASE/thymeleaf-2.1.5.RELEASE.jar:/home/tozogabee/.m2/repository/ognl/ognl/3.0.8/ognl-3.0.8.jar:/home/tozogabee/.m2/repository/org/javassist/javassist/3.21.0-GA/javassist-3.21.0-GA.jar:/home/tozogabee/.m2/repository/org/unbescape/unbescape/1.1.0.RELEASE/unbescape-1.1.0.RELEASE.jar:/home/tozogabee/.m2/repository/org/slf4j/slf4j-api/1.7.24/slf4j-api-1.7.24.jar:/home/tozogabee/.m2/repository/nz/net/ultraq/thymeleaf/thymeleaf-layout-dialect/1.4.0/thymeleaf-layout-dialect-1.4.0.jar:/home/tozogabee/.m2/repository/org/codehaus/groovy/groovy/2.4.9/groovy-2.4.9.jar:/home/tozogabee/.m2/repository/org/springframework/boot/spring-boot-devtools/1.5.2.RELEASE/spring-boot-devtools-1.5.2.RELEASE.jar App
19:32:22.912 [main] DEBUG org.springframework.boot.devtools.settings.DevToolsSettings - Included patterns for restart : []
19:32:22.916 [main] DEBUG org.springframework.boot.devtools.settings.DevToolsSettings - Excluded patterns for restart : [/spring-boot-starter/target/classes/, /spring-boot-autoconfigure/target/classes/, /spring-boot-starter-[\w-]+/, /spring-boot/target/classes/, /spring-boot-actuator/target/classes/, /spring-boot-devtools/target/classes/]
19:32:22.916 [main] DEBUG org.springframework.boot.devtools.restart.ChangeableUrls - Matching URLs for reloading : [file:/home/tozogabee/workspace/webapp/target/classes/]

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.2.RELEASE)

2017-08-27 19:32:23.201  INFO 20906 --- [  restartedMain] App                                      : Starting App on tozogabee-ThinkPad-T420 with PID 20906 (/home/tozogabee/workspace/webapp/target/classes started by tozogabee in /home/tozogabee/workspace/webapp)
2017-08-27 19:32:23.202  INFO 20906 --- [  restartedMain] App                                      : No active profile set, falling back to default profiles: default
2017-08-27 19:32:23.523  INFO 20906 --- [  restartedMain] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@68eaabd3: startup date [Sun Aug 27 19:32:23 CEST 2017]; root of context hierarchy
2017-08-27 19:32:23.557  WARN 20906 --- [  restartedMain] ionWarningsApplicationContextInitializer : 

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


2017-08-27 19:32:31.359  WARN 20906 --- [  restartedMain] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [App]; nested exception is java.io.FileNotFoundException: class path resource [org/springframework/social/config/annotation/SocialConfigurerAdapter.class] cannot be opened because it does not exist
2017-08-27 19:32:31.362 ERROR 20906 --- [  restartedMain] o.s.b.f.s.DefaultListableBeanFactory     : Destroy method on bean with name 'org.springframework.boot.autoconfigure.internalCachingMetadataReaderFactory' threw an exception

java.lang.IllegalStateException: ApplicationEventMulticaster not initialized - call 'refresh' before multicasting events via the context: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@68eaabd3: startup date [Sun Aug 27 19:32:23 CEST 2017]; root of context hierarchy
    at org.springframework.context.support.AbstractApplicationContext.getApplicationEventMulticaster(AbstractApplicationContext.java:404) [spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.ApplicationListenerDetector.postProcessBeforeDestruction(ApplicationListenerDetector.java:97) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DisposableBeanAdapter.destroy(DisposableBeanAdapter.java:253) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroyBean(DefaultSingletonBeanRegistry.java:578) [spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingleton(DefaultSingletonBeanRegistry.java:554) [spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingleton(DefaultListableBeanFactory.java:961) [spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingletons(DefaultSingletonBeanRegistry.java:523) [spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.destroySingletons(DefaultListableBeanFactory.java:968) [spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.destroyBeans(AbstractApplicationContext.java:1033) [spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:555) [spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at App.main(App.java:9) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.5.2.RELEASE.jar:1.5.2.RELEASE]

2017-08-27 19:32:31.371 ERROR 20906 --- [  restartedMain] o.s.boot.SpringApplication               : Application startup failed

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [App]; nested exception is java.io.FileNotFoundException: class path resource [org/springframework/social/config/annotation/SocialConfigurerAdapter.class] cannot be opened because it does not exist
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:180) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:308) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:228) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:270) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:686) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:524) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at App.main(App.java:9) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.5.2.RELEASE.jar:1.5.2.RELEASE]
Caused by: java.io.FileNotFoundException: class path resource [org/springframework/social/config/annotation/SocialConfigurerAdapter.class] cannot be opened because it does not exist
    at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:172) ~[spring-core-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:50) ~[spring-core-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:98) ~[spring-core-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.createMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:89) ~[spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.getMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:76) ~[spring-boot-1.5.2.RELEASE.jar:1.5.2.RELEASE]
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:93) ~[spring-core-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.asSourceClass(ConfigurationClassParser.java:681) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser$SourceClass.getSuperClass(ConfigurationClassParser.java:845) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:322) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:244) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:189) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:286) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:244) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:197) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:166) ~[spring-context-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    ... 18 common frames omitted

And in the resources/templates there is an index.htm file.

Please help,all tutorials are low cost. I did not find correct resolution,only saint talks.

My pom xml is

<?xml version="1.0" encoding="UTF-8"?>

http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4.0.0

<groupId>com.kw</groupId>
<artifactId>webapp</artifactId>
<version>1.0-SNAPSHOT</version>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.2.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
    </dependency>
</dependencies>

Answer 1

When @SpringBootApplication starts it will activate a @ComponentScan that occurs from the package of the class that declares it. Although your @SpringBootApplication is declared in a class that is located at the default package. This is the reason why the components that are inside of Controller package are not scanned by default.

This is the warning message that Spring Boot shows when it detects that @ComponentScan is performed at the default package

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

One possible solution is to move your App class inside of Controller package in order to perform the @ComponentScan at the Controller package and let Spring discover the rest of elements that are not present at the default package.

Consider to use the following approach in order to organize you app

1. use a main package like: com.myorg.package and inside of it put your main class where @SpringBootApplication is annotated.

2. inside of com.myorg.package add sub packages for example controller, domain, configuration and others.

3. Since your @SpringBootApplication is in a class located at the base package it will scan all the rest of components that are inside of it

Answer 2

Move both classes to the same package or add a @ComponentScan annotation and mention the packages need to be scanned.