Spring Boot 애플리케이션의 auto-configuration 정보를 확인하거나 DEBUG 레벨의 로그를 확인하려면 아래와 같이 --debug나 -Ddebug 옵션을 주면 됩니다.

$ java -jar myapp.jar --debug

그리고 문서에서는 확인이 안되지만 applicaton.properties 파일에, 값 없이 debug 키를 선언해도 됩니다(debug: 혹은 debug=).

debug:
spring.datasource.url: jdbc:hsqldb:file:D:/tmp/hsqldb/scratchdb
spring.jpa.show-sql: true
spring.jpa.generate-ddl: true
spring.jpa.hibernate.ddl-auto: create

이렇게 debug 옵션을 주면 auto-configuration 정보와 사용 중인 framework, library 등의 DEBUG 레벨 로그를 확인할 수 있습니다.

아래는 --debug 옵션과 함께 Spring Data JPA 앱의 테스트케이스를 실행했을 때의 콘솔 로그입니다.

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::  (v1.3.0.BUILD-SNAPSHOT)

2015-04-17 13:17:28.927  INFO 5124 --- [           main] c.i.rt.execution.junit.JUnitStarter      : Starting JUnitStarter on envy-i7 with PID 5124 (started by kyutae.park in D:\dev\repos\spring-boot-data-jpa-javaworld)
2015-04-17 13:17:28.928 DEBUG 5124 --- [           main] o.s.boot.SpringApplication               : Loading source class sample.data.jpa.SampleDataJpaApplication
2015-04-17 13:17:29.243 DEBUG 5124 --- [           main] o.s.b.c.c.ConfigFileApplicationListener  : Skipped config file 'file:./config/application.yaml' resource not found

    ..............
    .... 중략 ....
    ..............

Hibernate: alter table tb_person_02837_cars add constraint FK_enugsq5f3484moat7h2ggrf1a foreign key (tb_person_02837_id) references tb_person_02837
2015-04-17 13:17:43.191  INFO 5124 --- [           main] org.hibernate.tool.hbm2ddl.SchemaExport  : HHH000230: Schema export complete
2015-04-17 13:17:45.352 DEBUG 5124 --- [           main] utoConfigurationReportLoggingInitializer : 


=========================
AUTO-CONFIGURATION REPORT
=========================


Positive matches:
-----------------

   AopAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.context.annotation.EnableAspectJAutoProxy,org.aspectj.lang.annotation.Aspect,org.aspectj.lang.reflect.Advice (OnClassCondition)
      - matched (OnPropertyCondition)

   AopAutoConfiguration.JdkDynamicAutoProxyConfiguration
      - matched (OnPropertyCondition)

   DataSourceAutoConfiguration
      - @ConditionalOnClass classes found: javax.sql.DataSource,org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType (OnClassCondition)

   DataSourceAutoConfiguration.DataSourceInitializerConfiguration
      - @ConditionalOnMissingBean (types: org.springframework.boot.autoconfigure.jdbc.DataSourceInitializer; SearchStrategy: all) found no beans (OnBeanCondition)

   DataSourceAutoConfiguration.JdbcTemplateConfiguration
      - existing auto database detected (DataSourceAutoConfiguration.DataSourceAvailableCondition)

   DataSourceAutoConfiguration.JdbcTemplateConfiguration#jdbcTemplate
      - @ConditionalOnMissingBean (types: org.springframework.jdbc.core.JdbcOperations; SearchStrategy: all) found no beans (OnBeanCondition)

   DataSourceAutoConfiguration.JdbcTemplateConfiguration#namedParameterJdbcTemplate
      - @ConditionalOnMissingBean (types: org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations; SearchStrategy: all) found no beans (OnBeanCondition)

   DataSourceAutoConfiguration.NonEmbeddedConfiguration
      - supported DataSource class found (DataSourceAutoConfiguration.NonEmbeddedDataSourceCondition)
      - @ConditionalOnMissingBean (types: javax.sql.DataSource,javax.sql.XADataSource; SearchStrategy: all) found no beans (OnBeanCondition)

   DataSourcePoolMetadataProvidersConfiguration.TomcatDataSourcePoolMetadataProviderConfiguration
      - @ConditionalOnClass classes found: org.apache.tomcat.jdbc.pool.DataSource (OnClassCondition)

   DataSourceTransactionManagerAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.jdbc.core.JdbcTemplate,org.springframework.transaction.PlatformTransactionManager (OnClassCondition)

   DataSourceTransactionManagerAutoConfiguration.TransactionManagementConfiguration
      - @ConditionalOnMissingBean (types: org.springframework.transaction.annotation.AbstractTransactionManagementConfiguration; SearchStrategy: all) found no beans (OnBeanCondition)

   GenericCacheConfiguration
      - Automatic cache type (CacheCondition)

   HibernateJpaAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean,org.springframework.transaction.annotation.EnableTransactionManagement,javax.persistence.EntityManager (OnClassCondition)
      - found HibernateEntityManager class (HibernateJpaAutoConfiguration.HibernateEntityManagerCondition)

   HttpEncodingAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.web.filter.CharacterEncodingFilter (OnClassCondition)
      - matched (OnPropertyCondition)

   HttpEncodingAutoConfiguration#characterEncodingFilter
      - @ConditionalOnMissingBean (types: org.springframework.web.filter.CharacterEncodingFilter; SearchStrategy: all) found no beans (OnBeanCondition)

   HttpMessageConvertersAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.http.converter.HttpMessageConverter (OnClassCondition)

   HttpMessageConvertersAutoConfiguration#messageConverters
      - @ConditionalOnMissingBean (types: org.springframework.boot.autoconfigure.web.HttpMessageConverters; SearchStrategy: all) found no beans (OnBeanCondition)

   HttpMessageConvertersAutoConfiguration.StringHttpMessageConverterConfiguration
      - @ConditionalOnClass classes found: org.springframework.http.converter.StringHttpMessageConverter (OnClassCondition)

   HttpMessageConvertersAutoConfiguration.StringHttpMessageConverterConfiguration#stringHttpMessageConverter
      - @ConditionalOnMissingBean (types: org.springframework.http.converter.StringHttpMessageConverter; SearchStrategy: all) found no beans (OnBeanCondition)

   JacksonAutoConfiguration
      - @ConditionalOnClass classes found: com.fasterxml.jackson.databind.ObjectMapper (OnClassCondition)

   JacksonAutoConfiguration.JacksonObjectMapperBuilderConfiguration
      - @ConditionalOnClass classes found: com.fasterxml.jackson.databind.ObjectMapper,org.springframework.http.converter.json.Jackson2ObjectMapperBuilder (OnClassCondition)

   JacksonAutoConfiguration.JacksonObjectMapperBuilderConfiguration#jacksonObjectMapperBuilder
      - @ConditionalOnMissingBean (types: org.springframework.http.converter.json.Jackson2ObjectMapperBuilder; SearchStrategy: all) found no beans (OnBeanCondition)

   JacksonAutoConfiguration.JacksonObjectMapperConfiguration
      - @ConditionalOnClass classes found: com.fasterxml.jackson.databind.ObjectMapper,org.springframework.http.converter.json.Jackson2ObjectMapperBuilder (OnClassCondition)

   JacksonAutoConfiguration.JacksonObjectMapperConfiguration#jacksonObjectMapper
      - @ConditionalOnMissingBean (types: com.fasterxml.jackson.databind.ObjectMapper; SearchStrategy: all) found no beans (OnBeanCondition)

   JacksonHttpMessageConvertersConfiguration.MappingJackson2HttpMessageConverterConfiguration
      - @ConditionalOnClass classes found: com.fasterxml.jackson.databind.ObjectMapper (OnClassCondition)
      - matched (OnPropertyCondition)
      - @ConditionalOnBean (types: com.fasterxml.jackson.databind.ObjectMapper; SearchStrategy: all) found the following [jacksonObjectMapper] (OnBeanCondition)

   JacksonHttpMessageConvertersConfiguration.MappingJackson2HttpMessageConverterConfiguration#mappingJackson2HttpMessageConverter
      - @ConditionalOnMissingBean (types: org.springframework.http.converter.json.MappingJackson2HttpMessageConverter; SearchStrategy: all) found no beans (OnBeanCondition)

   JpaBaseConfiguration#entityManagerFactory
      - @ConditionalOnMissingBean (types: org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean; SearchStrategy: all) found no beans (OnBeanCondition)

   JpaBaseConfiguration#entityManagerFactoryBuilder
      - @ConditionalOnMissingBean (types: org.springframework.boot.autoconfigure.orm.jpa.EntityManagerFactoryBuilder; SearchStrategy: all) found no beans (OnBeanCondition)

   JpaBaseConfiguration#jpaVendorAdapter
      - @ConditionalOnMissingBean (types: org.springframework.orm.jpa.JpaVendorAdapter; SearchStrategy: all) found no beans (OnBeanCondition)

   JpaBaseConfiguration#transactionManager
      - @ConditionalOnMissingBean (types: org.springframework.transaction.PlatformTransactionManager; SearchStrategy: all) found no beans (OnBeanCondition)

   JtaAutoConfiguration
      - @ConditionalOnClass classes found: javax.transaction.Transaction (OnClassCondition)
      - matched (OnPropertyCondition)

   MultipartAutoConfiguration
      - @ConditionalOnClass classes found: javax.servlet.Servlet,org.springframework.web.multipart.support.StandardServletMultipartResolver,javax.servlet.MultipartConfigElement (OnClassCondition)
      - matched (OnPropertyCondition)

   MultipartAutoConfiguration#multipartConfigElement
      - @ConditionalOnMissingBean (types: javax.servlet.MultipartConfigElement; SearchStrategy: all) found no beans (OnBeanCondition)

   MultipartAutoConfiguration#multipartResolver
      - @ConditionalOnMissingBean (types: org.springframework.web.multipart.MultipartResolver; SearchStrategy: all) found no beans (OnBeanCondition)

   NoOpCacheConfiguration
      - Automatic cache type (CacheCondition)

   PersistenceExceptionTranslationAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor (OnClassCondition)

   PersistenceExceptionTranslationAutoConfiguration#persistenceExceptionTranslationPostProcessor
      - @ConditionalOnMissingBean (types: org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor; SearchStrategy: all) found no beans (OnBeanCondition)
      - matched (OnPropertyCondition)

   PropertyPlaceholderAutoConfiguration#propertySourcesPlaceholderConfigurer
      - @ConditionalOnMissingBean (types: org.springframework.context.support.PropertySourcesPlaceholderConfigurer; SearchStrategy: current) found no beans (OnBeanCondition)

   RedisCacheConfiguration
      - Automatic cache type (CacheCondition)

   SimpleCacheConfiguration
      - Automatic cache type (CacheCondition)

   TransactionAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.transaction.support.TransactionTemplate,org.springframework.transaction.PlatformTransactionManager (OnClassCondition)
      - @ConditionalOnSingleCandidate (types: org.springframework.transaction.PlatformTransactionManager; SearchStrategy: all) found a primary candidate amongst the following [transactionManager] (OnBeanCondition)

   TransactionAutoConfiguration#transactionTemplate
      - @ConditionalOnMissingBean (types: org.springframework.transaction.support.TransactionTemplate; SearchStrategy: all) found no beans (OnBeanCondition)

   WebSocketAutoConfiguration
      - @ConditionalOnClass classes found: javax.servlet.Servlet,javax.websocket.server.ServerContainer (OnClassCondition)

   WebSocketAutoConfiguration.TomcatWebSocketConfiguration
      - @ConditionalOnClass classes found: org.apache.catalina.startup.Tomcat,org.apache.tomcat.websocket.server.WsSci (OnClassCondition)

   WebSocketAutoConfiguration.TomcatWebSocketConfiguration#websocketContainerCustomizer
      - @ConditionalOnMissingBean (names: websocketContainerCustomizer; SearchStrategy: all) found no beans (OnBeanCondition)


Negative matches:
-----------------

   ActiveMQAutoConfiguration
      - required @ConditionalOnClass classes not found: javax.jms.ConnectionFactory,org.apache.activemq.ActiveMQConnectionFactory (OnClassCondition)

   AopAutoConfiguration.CglibAutoProxyConfiguration
      - @ConditionalOnProperty missing required properties spring.aop.proxy-target-class  (OnPropertyCondition)

   AtomikosJtaConfiguration
      - required @ConditionalOnClass classes not found: com.atomikos.icatch.jta.UserTransactionManager (OnClassCondition)

   BatchAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.batch.core.launch.JobLauncher (OnClassCondition)

   BitronixJtaConfiguration
      - required @ConditionalOnClass classes not found: bitronix.tm.jndi.BitronixContext (OnClassCondition)

   CacheAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.cache.CacheManager (OnClassCondition)
      - @ConditionalOnBean (types: org.springframework.cache.interceptor.CacheAspectSupport; SearchStrategy: all) found no beans (OnBeanCondition)

   CloudAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.cloud.config.java.CloudScanConfiguration (OnClassCondition)

   DataSourceAutoConfiguration.EmbeddedConfiguration
      - existing non-embedded database detected (DataSourceAutoConfiguration.EmbeddedDataSourceCondition)

   DataSourceAutoConfiguration.TomcatDataSourceJmxConfiguration
      - @ConditionalOnClass classes found: org.apache.tomcat.jdbc.pool.DataSourceProxy (OnClassCondition)
      - existing auto database detected (DataSourceAutoConfiguration.DataSourceAvailableCondition)
      - @ConditionalOnProperty missing required properties spring.datasource.jmx-enabled  (OnPropertyCondition)

   DataSourcePoolMetadataProvidersConfiguration.CommonsDbcpPoolDataSourceMetadataProviderConfiguration
      - required @ConditionalOnClass classes not found: org.apache.commons.dbcp.BasicDataSource (OnClassCondition)

   DataSourcePoolMetadataProvidersConfiguration.HikariPoolDataSourceMetadataProviderConfiguration
      - required @ConditionalOnClass classes not found: com.zaxxer.hikari.HikariDataSource (OnClassCondition)

   DataSourceTransactionManagerAutoConfiguration#transactionManager
      - @ConditionalOnMissingBean (names: transactionManager; SearchStrategy: all) found the following [transactionManager] (OnBeanCondition)

   DeviceDelegatingViewResolverAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.mobile.device.view.LiteDeviceDelegatingViewResolver (OnClassCondition)

   DeviceResolverAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.mobile.device.DeviceResolverHandlerInterceptor,org.springframework.mobile.device.DeviceHandlerMethodArgumentResolver (OnClassCondition)

   DispatcherServletAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.web.servlet.DispatcherServlet (OnClassCondition)
      - not a web application (OnWebApplicationCondition)

   EhCacheCacheConfiguration
      - required @ConditionalOnClass classes not found: net.sf.ehcache.Cache,org.springframework.cache.ehcache.EhCacheCacheManager (OnClassCondition)

   ElasticsearchAutoConfiguration
      - required @ConditionalOnClass classes not found: org.elasticsearch.client.Client,org.springframework.data.elasticsearch.client.TransportClientFactoryBean,org.springframework.data.elasticsearch.client.NodeClientFactoryBean (OnClassCondition)

   ElasticsearchDataAutoConfiguration
      - required @ConditionalOnClass classes not found: org.elasticsearch.client.Client,org.springframework.data.elasticsearch.core.ElasticsearchTemplate (OnClassCondition)

   ElasticsearchRepositoriesAutoConfiguration
      - required @ConditionalOnClass classes not found: org.elasticsearch.client.Client,org.springframework.data.elasticsearch.repository.ElasticsearchRepository (OnClassCondition)

   EmbeddedServletContainerAutoConfiguration
      - not a web application (OnWebApplicationCondition)

   ErrorMvcAutoConfiguration
      - @ConditionalOnClass classes found: javax.servlet.Servlet,org.springframework.web.servlet.DispatcherServlet (OnClassCondition)
      - not a web application (OnWebApplicationCondition)

   FacebookAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.social.config.annotation.SocialConfigurerAdapter,org.springframework.social.facebook.connect.FacebookConnectionFactory (OnClassCondition)

   FallbackWebSecurityAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.security.config.annotation.web.configuration.EnableWebSecurity (OnClassCondition)

   FlywayAutoConfiguration
      - required @ConditionalOnClass classes not found: org.flywaydb.core.Flyway (OnClassCondition)

   FreeMarkerAutoConfiguration
      - required @ConditionalOnClass classes not found: freemarker.template.Configuration,org.springframework.ui.freemarker.FreeMarkerConfigurationFactory (OnClassCondition)

   GroovyTemplateAutoConfiguration
      - required @ConditionalOnClass classes not found: groovy.text.markup.MarkupTemplateEngine (OnClassCondition)

   GsonAutoConfiguration
      - required @ConditionalOnClass classes not found: com.google.gson.Gson (OnClassCondition)

   GsonHttpMessageConvertersConfiguration
      - required @ConditionalOnClass classes not found: com.google.gson.Gson (OnClassCondition)

   GuavaCacheConfiguration
      - required @ConditionalOnClass classes not found: com.google.common.cache.CacheBuilder,org.springframework.cache.guava.GuavaCacheManager (OnClassCondition)

   GzipFilterAutoConfiguration
      - required @ConditionalOnClass classes not found: org.eclipse.jetty.servlets.GzipFilter (OnClassCondition)

   HazelcastCacheConfiguration
      - required @ConditionalOnClass classes not found: com.hazelcast.core.HazelcastInstance,com.hazelcast.spring.cache.HazelcastCacheManager (OnClassCondition)

   HornetQAutoConfiguration
      - required @ConditionalOnClass classes not found: javax.jms.ConnectionFactory,org.hornetq.api.jms.HornetQJMSClient (OnClassCondition)

   HypermediaAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.hateoas.Resource,org.springframework.plugin.core.Plugin (OnClassCondition)

   IntegrationAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.integration.config.EnableIntegration (OnClassCondition)

   JCacheCacheConfiguration
      - required @ConditionalOnClass classes not found: javax.cache.Caching,org.springframework.cache.jcache.JCacheCacheManager (OnClassCondition)

   JacksonAutoConfiguration.JodaDateTimeJacksonConfiguration
      - required @ConditionalOnClass classes not found: org.joda.time.DateTime,com.fasterxml.jackson.datatype.joda.ser.DateTimeSerializer,com.fasterxml.jackson.datatype.joda.cfg.JacksonJodaDateFormat (OnClassCondition)

   JacksonHttpMessageConvertersConfiguration.MappingJackson2XmlHttpMessageConverterConfiguration
      - required @ConditionalOnClass classes not found: com.fasterxml.jackson.dataformat.xml.XmlMapper (OnClassCondition)

   JerseyAutoConfiguration
      - required @ConditionalOnClass classes not found: org.glassfish.jersey.server.spring.SpringComponentProvider (OnClassCondition)

   JmsAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.jms.core.JmsTemplate (OnClassCondition)

   JmxAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.jmx.export.MBeanExporter (OnClassCondition)
      - @ConditionalOnProperty expected 'true' for properties spring.jmx.enabled (OnPropertyCondition)

   JndiConnectionFactoryAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.jms.core.JmsTemplate (OnClassCondition)

   JndiDataSourceAutoConfiguration
      - @ConditionalOnClass classes found: javax.sql.DataSource,org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType (OnClassCondition)
      - @ConditionalOnProperty missing required properties spring.datasource.jndi-name  (OnPropertyCondition)

   JndiJtaConfiguration
      - @ConditionalOnClass classes found: org.springframework.transaction.jta.JtaTransactionManager (OnClassCondition)
      - JNDI environment is not available (OnJndiCondition)

   JpaBaseConfiguration.JpaWebConfiguration
      - @ConditionalOnClass classes found: org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter (OnClassCondition)
      - not a web application (OnWebApplicationCondition)

   JpaRepositoriesAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.data.jpa.repository.JpaRepository (OnClassCondition)
      - matched (OnPropertyCondition)
      - @ConditionalOnMissingBean (types: org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean,org.springframework.data.jpa.repository.config.JpaRepositoryConfigExtension; SearchStrategy: all) found the following [&personRepository, &reviewRepository, &cityRepository, &hotelRepository, &carRepository, org.springframework.data.jpa.repository.config.JpaRepositoryConfigExtension#0] (OnBeanCondition)

   LinkedInAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.social.config.annotation.SocialConfigurerAdapter,org.springframework.social.linkedin.connect.LinkedInConnectionFactory (OnClassCondition)

   LiquibaseAutoConfiguration
      - required @ConditionalOnClass classes not found: liquibase.integration.spring.SpringLiquibase (OnClassCondition)

   MailSenderAutoConfiguration
      - required @ConditionalOnClass classes not found: javax.mail.internet.MimeMessage (OnClassCondition)

   MessageSourceAutoConfiguration
      - No bundle found for spring.messages.basename: messages (MessageSourceAutoConfiguration.ResourceBundleCondition)

   MongoAutoConfiguration
      - required @ConditionalOnClass classes not found: com.mongodb.Mongo (OnClassCondition)

   MongoDataAutoConfiguration
      - required @ConditionalOnClass classes not found: com.mongodb.Mongo,org.springframework.data.mongodb.core.MongoTemplate (OnClassCondition)

   MongoRepositoriesAutoConfiguration
      - required @ConditionalOnClass classes not found: com.mongodb.Mongo,org.springframework.data.mongodb.repository.MongoRepository (OnClassCondition)

   MustacheAutoConfiguration
      - required @ConditionalOnClass classes not found: com.samskivert.mustache.Mustache (OnClassCondition)

   RabbitAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.amqp.rabbit.core.RabbitTemplate,com.rabbitmq.client.Channel (OnClassCondition)

   ReactorAutoConfiguration
      - required @ConditionalOnClass classes not found: reactor.spring.context.config.EnableReactor,reactor.core.Environment (OnClassCondition)

   RedisAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.data.redis.connection.jedis.JedisConnection,org.springframework.data.redis.core.RedisOperations,redis.clients.jedis.Jedis (OnClassCondition)

   RepositoryRestMvcAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.data.rest.webmvc.config.RepositoryRestMvcConfiguration (OnClassCondition)

   SecurityAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.security.authentication.AuthenticationManager,org.springframework.security.config.annotation.authentication.configurers.GlobalAuthenticationConfigurerAdapter (OnClassCondition)

   SendGridAutoConfiguration
      - required @ConditionalOnClass classes not found: com.sendgrid.SendGrid (OnClassCondition)

   ServerPropertiesAutoConfiguration
      - not a web application (OnWebApplicationCondition)

   SitePreferenceAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.mobile.device.site.SitePreferenceHandlerInterceptor,org.springframework.mobile.device.site.SitePreferenceHandlerMethodArgumentResolver (OnClassCondition)

   SocialWebAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.social.connect.web.ConnectController,org.springframework.social.config.annotation.SocialConfigurerAdapter (OnClassCondition)

   SolrAutoConfiguration
      - required @ConditionalOnClass classes not found: org.apache.solr.client.solrj.impl.HttpSolrServer,org.apache.solr.client.solrj.impl.CloudSolrServer (OnClassCondition)

   SolrRepositoriesAutoConfiguration
      - required @ConditionalOnClass classes not found: org.apache.solr.client.solrj.SolrServer,org.springframework.data.solr.repository.SolrRepository (OnClassCondition)

   SpringDataWebAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.data.web.PageableHandlerMethodArgumentResolver,org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter (OnClassCondition)
      - not a web application (OnWebApplicationCondition)

   ThymeleafAutoConfiguration
      - required @ConditionalOnClass classes not found: org.thymeleaf.spring4.SpringTemplateEngine (OnClassCondition)

   TwitterAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.social.config.annotation.SocialConfigurerAdapter,org.springframework.social.twitter.connect.TwitterConnectionFactory (OnClassCondition)

   VelocityAutoConfiguration
      - required @ConditionalOnClass classes not found: org.apache.velocity.app.VelocityEngine,org.springframework.ui.velocity.VelocityEngineFactory (OnClassCondition)

   WebMvcAutoConfiguration
      - @ConditionalOnClass classes found: javax.servlet.Servlet,org.springframework.web.servlet.DispatcherServlet,org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter (OnClassCondition)
      - not a web application (OnWebApplicationCondition)

   WebSocketAutoConfiguration.JettyWebSocketConfiguration
      - required @ConditionalOnClass classes not found: org.eclipse.jetty.websocket.jsr356.server.deploy.WebSocketServerContainerInitializer (OnClassCondition)

   WebSocketAutoConfiguration.UndertowWebSocketConfiguration
      - required @ConditionalOnClass classes not found: io.undertow.websockets.jsr.Bootstrap (OnClassCondition)

   XADataSourceAutoConfiguration
      - @ConditionalOnClass classes found: javax.sql.DataSource,javax.transaction.TransactionManager,org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType (OnClassCondition)
      - @ConditionalOnBean (types: org.springframework.boot.jta.XADataSourceWrapper; SearchStrategy: all) found no beans (OnBeanCondition)


Exclusions:
-----------

    None



2015-04-17 13:17:45.388  INFO 5124 --- [           main] c.i.rt.execution.junit.JUnitStarter      : Started JUnitStarter in 23.914 seconds (JVM running for 45.382)
2015-04-17 13:17:45.461 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select count(city0_.id) as col_0_0_ from city city0_
Hibernate: select count(city0_.id) as col_0_0_ from city city0_
2015-04-17 13:17:45.468 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select city0_.id as id1_0_, city0_.country as country2_0_, city0_.map as map3_0_, city0_.name as name4_0_, city0_.state as state5_0_ from city city0_ order by city0_.name asc limit ?
Hibernate: select city0_.id as id1_0_, city0_.country as country2_0_, city0_.map as map3_0_, city0_.name as name4_0_, city0_.state as state5_0_ from city city0_ order by city0_.name asc limit ?
2015-04-17 13:17:45.490 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select count(hotel0_.id) as col_0_0_ from hotel hotel0_ left outer join review reviews1_ on hotel0_.id=reviews1_.hotel_id where hotel0_.city_id=? group by hotel0_.id
Hibernate: select count(hotel0_.id) as col_0_0_ from hotel hotel0_ left outer join review reviews1_ on hotel0_.id=reviews1_.hotel_id where hotel0_.city_id=? group by hotel0_.id
2015-04-17 13:17:45.502 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select hotel0_.city_id as col_0_0_, hotel0_.name as col_1_0_, avg(cast(reviews1_.rating as double)) as col_2_0_ from hotel hotel0_ left outer join review reviews1_ on hotel0_.id=reviews1_.hotel_id inner join city city2_ on hotel0_.city_id=city2_.id where hotel0_.city_id=? group by hotel0_.id order by hotel0_.name asc limit ?
Hibernate: select hotel0_.city_id as col_0_0_, hotel0_.name as col_1_0_, avg(cast(reviews1_.rating as double)) as col_2_0_ from hotel hotel0_ left outer join review reviews1_ on hotel0_.id=reviews1_.hotel_id inner join city city2_ on hotel0_.city_id=city2_.id where hotel0_.city_id=? group by hotel0_.id order by hotel0_.name asc limit ?
2015-04-17 13:17:45.515 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select city0_.id as id1_0_0_, city0_.country as country2_0_0_, city0_.map as map3_0_0_, city0_.name as name4_0_0_, city0_.state as state5_0_0_ from city city0_ where city0_.id=?
Hibernate: select city0_.id as id1_0_0_, city0_.country as country2_0_0_, city0_.map as map3_0_0_, city0_.name as name4_0_0_, city0_.state as state5_0_0_ from city city0_ where city0_.id=?
2015-04-17 13:17:45.520  WARN 5124 --- [           main] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Warning Code: -1003, SQLState: 01003
2015-04-17 13:17:45.520  WARN 5124 --- [           main] o.h.engine.jdbc.spi.SqlExceptionHelper   : warning: null value eliminated in set function
2015-04-17 13:17:45.528 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select hotel0_.id as id1_1_, hotel0_.address as address2_1_, hotel0_.city_id as city_id5_1_, hotel0_.name as name3_1_, hotel0_.zip as zip4_1_ from hotel hotel0_ where hotel0_.city_id=? and hotel0_.name=?
Hibernate: select hotel0_.id as id1_1_, hotel0_.address as address2_1_, hotel0_.city_id as city_id5_1_, hotel0_.name as name3_1_, hotel0_.zip as zip4_1_ from hotel hotel0_ where hotel0_.city_id=? and hotel0_.name=?
2015-04-17 13:17:45.530 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select city0_.id as id1_0_0_, city0_.country as country2_0_0_, city0_.map as map3_0_0_, city0_.name as name4_0_0_, city0_.state as state5_0_0_ from city city0_ where city0_.id=?
Hibernate: select city0_.id as id1_0_0_, city0_.country as country2_0_0_, city0_.map as map3_0_0_, city0_.name as name4_0_0_, city0_.state as state5_0_0_ from city city0_ where city0_.id=?
2015-04-17 13:17:45.537 DEBUG 5124 --- [           main] org.hibernate.SQL                        : select review0_.rating as col_0_0_, count(review0_.id) as col_1_0_ from review review0_ where review0_.hotel_id=? group by review0_.rating order by review0_.rating DESC
Hibernate: select review0_.rating as col_0_0_, count(review0_.id) as col_1_0_ from review review0_ where review0_.hotel_id=? group by review0_.rating order by review0_.rating DESC
2015-04-17 13:17:45.543  INFO 5124 --- [       Thread-1] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@7050ad86: startup date [Fri Apr 17 13:17:29 GMT+09:00 2015]; root of context hierarchy
2015-04-17 13:17:45.548  INFO 5124 --- [       Thread-1] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'

Process finished with exit code 0

조금 길지만 auto-configuration에 관한 내용을 찬찬히 읽어 보면 어떻게 앱이 자동 설정되었는지 확인할 수 있습니다.

EOF

개요

요즘 Spring Boot 저장소에 있는 Spring Data JPA 샘플 프로젝트를 살펴 보고 있습니다.

테스트 코드를 작성하면서 하나하나 파악하고 있는데, OneToMany로 엮인 다른 엔티티의 목록을 가져오려고 하면 아래와 같은 오류가 발생합니다.

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: kr.co.javaworld.jpa.domain.Person.cars, could not initialize proxy - no Session
    at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:575)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:214)
    at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:155)
    at org.hibernate.collection.internal.PersistentBag.size(PersistentBag.java:278)
    at org.hamcrest.collection.IsCollectionWithSize.featureValueOf(IsCollectionWithSize.java:21)
    at org.hamcrest.collection.IsCollectionWithSize.featureValueOf(IsCollectionWithSize.java:14)
    at org.hamcrest.FeatureMatcher.matchesSafely(FeatureMatcher.java:40)
    at org.hamcrest.TypeSafeDiagnosingMatcher.matches(TypeSafeDiagnosingMatcher.java:55)
    at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:12)
    at org.junit.Assert.assertThat(Assert.java:956)
    at org.junit.Assert.assertThat(Assert.java:923)
    at kr.co.javaworld.jpa.service.PersonRepositoryIntegrationTests.testFindCars(PersonRepositoryIntegrationTests.java:46)
    ..............
    .... 중략 ....
    ..............
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)

늦은 초기화(Lazy initialization)에 관련된 예외 상황인데, 이에 대한 해결 방법을 정리해 봅니다.

예외가 발생하는 코드

아래의 테스트 코드를 실행하던 중 예외가 발생했습니다. testFindCars 메소드는 Person 객체를 하나 찾은 후, 다시 그 Person이 가진 Car 목록을 조회하는 테스트 코드입니다.

Person.getCars() 호출 후 목록(cars)의 크기를 얻으려고 하니까(assertThat(cars, hasSize(4))) 오류가 발생했습니다.

package kr.co.javaworld.jpa.service;

import kr.co.javaworld.jpa.domain.Car;
import kr.co.javaworld.jpa.domain.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import sample.data.jpa.SampleDataJpaApplication;

import javax.transaction.Transactional;
import java.util.List;

import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = SampleDataJpaApplication.class)
public class PersonRepositoryIntegrationTests {

    @Autowired
    PersonRepository repository;

    ..............
    .... 중략 ....
    ..............

    @Test
    public void testFindCars() {
        Person person = repository.findOne(1L);
        List<Car> cars = person.getCars();

        assertThat(cars, hasSize(4));
        assertThat(cars.get(0).getName(), is("Mercedes"));
    }
}

Person 엔티티의 코드입니다.
cars는 @OneToMany annotation이 붙어있을 뿐 특별한 점은 없습니다.

package kr.co.javaworld.jpa.domain;

import javax.persistence.*;
import java.util.List;

@Entity
@Table(name = "TB_PERSON_02837")
public class Person {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "PERSON_NAME", length = 100, unique = true, nullable = false)
    private String name;

    @OneToMany
    private List<Car> cars;

    ..............
    .... 중략 ....
    ..............

}

해결 방법

@OneToMany로 엮을 경우 JPA는 늦은 초기화를 통해 Person의 cars 목록을 가져오는게 기본 설정입니다. 즉, 위 코드의 @OneToMany annotation 선언은 @OneToMany(fetch = FetchType.LAZY)로 대체해도 동일합니다.

따라서 해결 방법은 간단합니다. 패치 타입을 FetchType.EAGER로 변경하여 늦은 초기화 대신 이른 초기화(Eager initialization)를 사용하면 됩니다.

아래 코드와 같이 @OneToMany(fetch = FetchType.EAGER)로 annotation 선언을 변경해 주면 오류가 사라집니다.

package kr.co.javaworld.jpa.domain;

import javax.persistence.*;
import java.util.List;

@Entity
@Table(name = "TB_PERSON_02837")
public class Person {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "PERSON_NAME", length = 100, unique = true, nullable = false)
    private String name;

    @OneToMany(fetch = FetchType.EAGER)
    private List<Car> cars;

    ..............
    .... 중략 ....
    ..............

}

다른 해결 방법

앞서의 해결 방법은 People 엔티티를 얻어 올 때는 언제나 Car 목록도 함께 가져오도록 강제합니다. 따라서 가끔씩만 Car 목록이 필요하다면 불필요한 메모리 낭비나 서버 성능 저하 등의 문제가 발생할 수 있습니다.

늦은 초기화를 사용하면서도 문제를 해결하려면 아래와 같이 트랜잭션을 Person.getCar() 호출 후 관련 동작을 완료할 때까지 유지하면 됩니다.

아래에서는 testFindCars 메소드에 @Transactional annotation을 붙여서 메소드 전체를 하나의 트랜잭션으로 감쌌습니다.

실무에서는 서비스 클래스의 메소드 단위로 트랜잭션을 잡아 주거나, 뷰 단의 서블릿 필터에서 UserTransaction을 이용하여 요청 단위로 트랜잭션을 처리하는 방법을 사용하면 됩니다.

package kr.co.javaworld.jpa.service;

import kr.co.javaworld.jpa.domain.Car;
import kr.co.javaworld.jpa.domain.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import sample.data.jpa.SampleDataJpaApplication;

import javax.transaction.Transactional;
import java.util.List;

import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = SampleDataJpaApplication.class)
public class PersonRepositoryIntegrationTests {

    @Autowired
    PersonRepository repository;

    ..............
    .... 중략 ....
    ..............

    @Test
    @Transactional
    public void testFindCars() {
        Person person = repository.findOne(1L);
        List<Car> cars = person.getCars();

        assertThat(cars, hasSize(4));
        assertThat(cars.get(0).getName(), is("Mercedes"));
    }
}

EOF

개요

HelloWorldCommands 클래스를 통해서 Spring Shell 커맨드 구현 방법을 살펴 보겠습니다.

Marker interface

HelloWorldCommands는 org.springframework.shell.core.CommandMarker 인터페이스를 구현하고 있습니다.

@Component
public class HelloWorldCommands implements CommandMarker {

}

CommandMarker는 마커 인터페이스라서 커맨드 구현체라는 것을 알려주기 위해서 implements 할 뿐입니다. 따라서 구현할 메소드는 없습니다.
@Component annotation은 component-scan을 통해 bean으로 등록되라고 붙여 줬습니다.

CLI Annotation

HelloWorldCommands는 모두 3개의 annotation을 사용하여 쉘에서의 동작을 제어합니다.

CliAvailabilityIndicator

어떤 커맨드가 쉘에서 사용 가능한지를 알려주기 위해서 사용합니다. 이 annotation은 boolean 값을 반환하는 메소드에 붙이며, 이 메소드는 annotation에 명시한 커맨드의 사용 가능 여부를 반환합니다.
HelloWorldCommands에서는 hw simple, hw complex, hw enum 커맨드의 사용 가능 여부를 알려 주기 위해서 사용하였습니다.

    private boolean simpleCommandExecuted = false;

    @CliAvailabilityIndicator({"hw simple"})
    public boolean isSimpleAvailable() {
        //always available
        return true;
    }

    @CliAvailabilityIndicator({"hw complex", "hw enum"})
    public boolean isComplexAvailable() {
        if (simpleCommandExecuted) {
            return true;
        } else {
            return false;
        }
    }

위에서 isSimpleAvailable() 메소드는 언제나 true를 반환하여, hw simple 커맨드가 언제나 사용 가능하다고 알려주고 있습니다.
또 isComplexAvailable 메소드는 simpleCommandExecuted 변수의 상태에 따라서 hw complex, hw enum 커맨드의 사용 가능 여부를 알려줍니다.

소개

스프링 프로그래밍 모델을 기반으로 손쉽게 커맨드라인 애플리케이션(interactive shell)을 만들 수 있도록 도와주는 프로젝트입니다.

홈페이지(GitHub)

https://github.com/spring-projects/spring-shell

샘플 애플리케이션

Spring Shell은 샘플 애플리케이션을 제공합니다. HelloWorld 애플리케이션은 부트스트랩(Bootstrap)/커맨드(Command)/베너(Banner)/프롬프트(Prompt)의 기본 구현 방법을 보여줍니다.
샘플을 통해 Spring Shell을 이해하는게 효과적이기 때문에 이를 통해 Spring Shell 사용 방법을 하나하나 설명토록 하겠습니다.

Clone

먼저 Spring Shell 프로젝트를 Clone합니다.

~$ git clone git@github.com:spring-projects/spring-shell.git

빌드 및 실행

Clone이 완료되면, samples/helloworld 디렉토리로 이동한 후 ./gradlew installApp 명령으로 HelloWorld 샘플을 빌드합니다.

~$ cd spring-shell/samples/helloworld
~/spring-shell/samples/helloworld$ ./gradlew installApp
:compileJava
:processResources
:classes
:jar
:startScripts
:installApp

BUILD SUCCESSFUL

./gradlew -q run 명령 혹은 build/install/helloworld/bin/helloworld 스크립트를 실행하면 HelloWorld 샘플을 실행할 수 있습니다.
build/install/helloworld 디렉토리에는 실행 스크립트(bin/helloworld)와 의존 라이브러리(lib/*.jar)가 모두 들어 있기 때문에 이 디렉토리만 배포하면 누구든 이 애플리케이션을 사용할 수 있게 됩니다.
사실 실행만 원한다면 빌드 없이 ./gradlew -q run 명령만 사용해도 됩니다.

~$ cd spring-shell/samples/helloworld
~/spring-shell/samples/helloworld$ ./gradlew -q run
=======================================
*                                     *
*            HelloWorld               *
*                                     *
=======================================
Version:1.2.3
Welcome to HelloWorld CLI
hw-shell>

구현 상세

HelloWorld는 아래 5개의 클래스로 구현되어 있었습니다.

• org.springframework.shell.samples.helloworld.Main
• org.springframework.shell.samples.helloworld.commands.HelloWorldCommands
• org.springframework.shell.samples.helloworld.commands.MyBannerProvider
• org.springframework.shell.samples.helloworld.commands.MyHistoryFileNameProvider
• org.springframework.shell.samples.helloworld.commands.MyPromptProvider

Main 클래스는 org.springframework.shell.Bootstrap 클래스의 main 메소드를 호출하여 애플리케이션을 실행합니다.

    /**
     * Main class that delegates to Spring Shell's Bootstrap class in order to simplify debugging inside an IDE
     * @param args
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {
        Bootstrap.main(args);
    }

이 때 "/META-INF/spring/spring-shell-plugin.xml" 파일을 이용해 ApplicationContext를 생성합니다. spring-shell-plugin.xml 파일은 다음과 같이 단촐합니다.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="org.springframework.shell.samples.helloworld.commands" />

</beans>

component-scan을 통해 bean을 찾기 때문에 Main 이외의 모든 클래스는 Component annotation을 달고 있습니다.

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class MyPromptProvider extends DefaultPromptProvider {

    @Override
    public String getPrompt() {
        return "hw-shell>";
    }


    @Override
    public String getProviderName() {
        return "My prompt provider";
    }

}

위의 MyPromptProvider 클래스는 Order annotation 또한 달고 있는데, 이는 혹 클래스 패스에 다른 plugin이 Provider(Banner/Prompt/HistoryFileName) 구현체를 가지고 있더라도 내가 구현한 Provider를 우선하도록(Ordered.HIGHEST_PRECEDENCE) 합니다. Provider에 대해서는 곧 설명합니다.

Provider는 Spring Shell이 쉘을 커스터마이징 할 수 있도록 제공하는 확장 포인트로 모두 org.springframework.shell.plugin.NamedProvider 인터페이스를 상속한 인터페이스입니다.

HelloWorld가 사용하는 구현 클래스는 모두 Spring Shell이 제공하는 각 Provider의 기본 구현체(DefaultXXXProvider)를 상속하고 있습니다. HelloWorld는 총 3개의 Provider 구현 클래스를 가지고 있습니다.

• MyBannerProvider는 이름이 알려주듯이 배너 정보를 담고 있는데, 이외에 버전정보(getVersion()), 환영 메시지(getWelcomeMessage()) 또한 제공합니다.
• MyPromptProvider는 프롬프트 모양을 정의(getPrompt())합니다.
• MyHistoryFileNameProvider는 쉘의 동작 히스토리를 담을 로그파일 이름(my.log)을 정의합니다.

MyHistoryFileNameProvider의 코드는 다음과 같습니다.

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class MyHistoryFileNameProvider extends DefaultHistoryFileNameProvider {

    public String getHistoryFileName() {
        return "my.log";
    }

    @Override
    public String getProviderName() {
        return "My history file name provider";
    }

}

MyBannerProvider의 코드는 다음과 같습니다.

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class MyBannerProvider extends DefaultBannerProvider  {

    public String getBanner() {
        StringBuffer buf = new StringBuffer();
        buf.append("=======================================" + OsUtils.LINE_SEPARATOR);
        buf.append("*                                     *"+ OsUtils.LINE_SEPARATOR);
        buf.append("*            HelloWorld               *" +OsUtils.LINE_SEPARATOR);
        buf.append("*                                     *"+ OsUtils.LINE_SEPARATOR);
        buf.append("=======================================" + OsUtils.LINE_SEPARATOR);
        buf.append("Version:" + this.getVersion());
        return buf.toString();
    }

    public String getVersion() {
        return "1.2.3";
    }

    public String getWelcomeMessage() {
        return "Welcome to HelloWorld CLI";
    }

    @Override
    public String getProviderName() {
        return "Hello World Banner";
    }
}

HelloWorld를 실행하면 배너와 버전 정보, 환영 메시지가 출력된 후 hw-shell> 프롬프트 옆에서 커서가 깜빡입니다.
앞에서 설명했듯이 이 때 출력되는 모든 정보는 MyBannerProvider가 제공하며, hw-shell> 프롬프트는 MyPromptProvider에서 정의하고 있습니다.
그리고 HelloWorld를 실행한 디렉토리를 탐색해 보면 MyHistoryFileNameProvider에서 정의한 my.log 파일이 생성된 것을 확인할 수 있습니다.

=======================================
*                                     *
*            HelloWorld               *
*                                     *
=======================================
Version:1.2.3
Welcome to HelloWorld CLI
hw-shell>

지금까지 Spring Shell에 대한 기본적인 내용과 Provider에 대해 알아봤습니다.
가장 중요한 커맨드 클래스에 대해서는 따로 글을 올리겠습니다.