为什么添加@EnableAutoConfiguration导致spring-boot失败并显示"无法找到要扫描的JPA包"

为什么添加@EnableAutoConfiguration到以下spring-boot应用程序会导致它无法创建entityManagerFactory？如果我删除@EnableAutoConfiguration一切正常.任何人都可以阐明这种行为吗？

package test.builder;

import javax.sql.DataSource;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.JpaVendorAdapter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.Database;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;

import test.builder.jpa.entity.Builder;
import test.builder.jpa.repository.BuilderRepository;

@Configuration
// @EnableAutoConfiguration
@EnableJpaRepositories("test.builder")
@PropertySource("classpath:application.properties")
public class BootApp implements CommandLineRunner {

    private static Logger logger = LoggerFactory.getLogger(BootApp.class);

    @Value("${spring.datasource.driverClassName}")
    private String databaseDriverClassName;

    @Value("${spring.datasource.url}")
    private String datasourceUrl;

    @Value("${spring.datasource.username}")
    private String databaseUsername;

    @Value("${spring.datasource.password}")
    private String databasePassword;

    @Bean
    public static PropertySourcesPlaceholderConfigurer placeHolderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean
    public DataSource dataSource() {

        org.apache.tomcat.jdbc.pool.DataSource ds = new org.apache.tomcat.jdbc.pool.DataSource();
        ds.setDriverClassName(databaseDriverClassName);
        ds.setUrl(datasourceUrl);
        ds.setUsername(databaseUsername);
        ds.setPassword(databasePassword);

        return ds;
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource,
            JpaVendorAdapter jpaVendorAdapter) {
        LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
        lef.setDataSource(dataSource);
        lef.setJpaVendorAdapter(jpaVendorAdapter);
        lef.setPackagesToScan("test.builder");

        return lef;
    }

    @Bean
    public JpaVendorAdapter jpaVendorAdapter() {
        HibernateJpaVendorAdapter hibernateJpaVendorAdapter = new HibernateJpaVendorAdapter();
        hibernateJpaVendorAdapter.setShowSql(true);
        hibernateJpaVendorAdapter.setGenerateDdl(false);
        hibernateJpaVendorAdapter.setDatabase(Database.SQL_SERVER);
        return hibernateJpaVendorAdapter;
    }

    @Bean
    public PlatformTransactionManager transactionManager() {
        return new JpaTransactionManager();
    }

    @Override
    public void run(String... args) {

        AbstractApplicationContext context = new AnnotationConfigApplicationContext(BootApp.class);
        BuilderRepository repository = context.getBean(BuilderRepository.class);
        Builder builder = repository.findOne(10);

        logger.info("Retrieved ", builder.toString());

        context.close();
    }

    public static void main(String[] args) {

        SpringApplication.run(BootApp.class, args);

    }

}

潜在的错误是

Unable to find JPA packages to scan, please define a @ComponentScan annotation or disable JpaAutoConfiguration

完整输出(包括堆栈跟踪)是 -

14:53:50,842 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback.groovy]
14:53:50,843 |-INFO in ch.qos.logback.classic.LoggerContext[default] - Could NOT find resource [logback-test.xml]
14:53:50,991 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
14:53:50,997 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
14:53:51,017 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
14:53:51,114 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to INFO
14:53:51,114 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT]
14:53:51,115 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration.
14:53:51,117 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@5ece2187 - Registering current configuration as safe fallback point

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::             (v0.5.0.M6)

14:53:51,849 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - About to instantiate appender of type [ch.qos.logback.core.ConsoleAppender]
14:53:51,854 |-INFO in ch.qos.logback.core.joran.action.AppenderAction - Naming appender as [STDOUT]
14:53:51,854 |-INFO in ch.qos.logback.core.joran.action.NestedComplexPropertyIA - Assuming default type [ch.qos.logback.classic.encoder.PatternLayoutEncoder] for [encoder] property
14:53:51,855 |-INFO in ch.qos.logback.classic.joran.action.RootLoggerAction - Setting level of ROOT logger to INFO
14:53:51,856 |-INFO in ch.qos.logback.core.joran.action.AppenderRefAction - Attaching appender named [STDOUT] to Logger[ROOT]
14:53:51,856 |-INFO in ch.qos.logback.classic.joran.action.ConfigurationAction - End of configuration.
14:53:51,856 |-INFO in ch.qos.logback.classic.joran.JoranConfigurator@722b9406 - Registering current configuration as safe fallback point
14:53:51.945 INFO  o.s.c.a.AnnotationConfigApplicationContext - Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@6490832e: startup date [Thu Dec 19 14:53:51 GMT 2013]; root of context hierarchy
14:53:52.829 INFO  o.s.b.f.s.DefaultListableBeanFactory - Overriding bean definition for bean 'transactionManager': replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=bootApp; factoryMethodName=transactionManager; initMethodName=null; destroyMethodName=(inferred); defined in class test.builder.BootApp] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration; factoryMethodName=transactionManager; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]]
14:53:52.830 INFO  o.s.b.f.s.DefaultListableBeanFactory - Overriding bean definition for bean 'entityManagerFactory': replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=bootApp; factoryMethodName=entityManagerFactory; initMethodName=null; destroyMethodName=(inferred); defined in class test.builder.BootApp] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration; factoryMethodName=entityManagerFactory; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]]
14:53:52.830 INFO  o.s.b.f.s.DefaultListableBeanFactory - Overriding bean definition for bean 'jpaVendorAdapter': replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=bootApp; factoryMethodName=jpaVendorAdapter; initMethodName=null; destroyMethodName=(inferred); defined in class test.builder.BootApp] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration; factoryMethodName=jpaVendorAdapter; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]]
Exception in thread "main" 14:53:53.382 INFO  o.s.b.a.AutoConfigurationReportLoggingInitializer$AutoConfigurationReportLogger - 


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


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

   MessageSourceAutoConfiguration
      - @ConditionalOnMissingBean (types: org.springframework.context.MessageSource; SearchStrategy: all) found no beans (OnBeanCondition)

   AopAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.context.annotation.EnableAspectJAutoProxy,org.aspectj.lang.annotation.Aspect,org.aspectj.lang.reflect.Advice (OnClassCondition)
      - SpEL expression on org.springframework.boot.autoconfigure.aop.AopAutoConfiguration: #{true} (OnExpressionCondition)
      - @ConditionalOnClass classes found: org.springframework.context.annotation.EnableAspectJAutoProxy,org.aspectj.lang.annotation.Aspect,org.aspectj.lang.reflect.Advice (OnClassCondition)
      - SpEL expression on org.springframework.boot.autoconfigure.aop.AopAutoConfiguration: #{true} (OnExpressionCondition)

   AopAutoConfiguration.JdkDynamicAutoProxyConfiguration
      - SpEL expression on org.springframework.boot.autoconfigure.aop.AopAutoConfiguration$JdkDynamicAutoProxyConfiguration: #{!false} (OnExpressionCondition)
      - SpEL expression on org.springframework.boot.autoconfigure.aop.AopAutoConfiguration$JdkDynamicAutoProxyConfiguration: #{!false} (OnExpressionCondition)

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

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

   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)

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

   HibernateJpaAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean,org.springframework.transaction.annotation.EnableTransactionManagement,javax.persistence.EntityManager,org.hibernate.ejb.HibernateEntityManager (OnClassCondition)
      - @ConditionalOnClass classes found: org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean,org.springframework.transaction.annotation.EnableTransactionManagement,javax.persistence.EntityManager,org.hibernate.ejb.HibernateEntityManager (OnClassCondition)
      - @ConditionalOnBean (types: javax.sql.DataSource; SearchStrategy: all) found the following [dataSource] (OnBeanCondition)

   ServerPropertiesAutoConfiguration#serverProperties
      - @ConditionalOnMissingBean (types: org.springframework.boot.context.embedded.properties.ServerProperties; SearchStrategy: all) found no beans (OnBeanCondition)


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

   PropertyPlaceholderAutoConfiguration#propertySourcesPlaceholderConfigurer
      - @ConditionalOnMissingBean (types: org.springframework.context.support.PropertySourcesPlaceholderConfigurer; SearchStrategy: current) found the following [placeHolderConfigurer] (OnBeanCondition)

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

   AopAutoConfiguration.CglibAutoProxyConfiguration
      - SpEL expression on org.springframework.boot.autoconfigure.aop.AopAutoConfiguration$CglibAutoProxyConfiguration: #{false} (OnExpressionCondition)

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

   JpaRepositoriesAutoConfiguration
      - @ConditionalOnClass classes found: org.springframework.data.jpa.repository.JpaRepository (OnClassCondition)
      - @ConditionalOnMissingBean (types: org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean; SearchStrategy: all) found the following [&builderRepository] (OnBeanCondition)

   JpaRepositoriesAutoConfiguration.JpaWebConfiguration
      - web application classes not found (OnWebApplicationCondition)

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

   DataSourceAutoConfiguration.DbcpConfiguration
      - tomcat DataSource (DataSourceAutoConfiguration.BasicDatabaseCondition)

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

   DataSourceAutoConfiguration.TomcatConfiguration
      - found database driver com.microsoft.sqlserver.jdbc.SQLServerDriver (DataSourceAutoConfiguration.TomcatDatabaseCondition)
      - found database driver com.microsoft.sqlserver.jdbc.SQLServerDriver (DataSourceAutoConfiguration.TomcatDatabaseCondition)
      - @ConditionalOnMissingBean (types: javax.sql.DataSource; SearchStrategy: all) found the following [dataSource] (OnBeanCondition)

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

   JmsTemplateAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.jms.core.JmsTemplate,javax.jms.ConnectionFactory (OnClassCondition)

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

   JpaBaseConfiguration.JpaWebConfiguration
      - web application classes not found (OnWebApplicationCondition)

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

   ThymeleafAutoConfiguration
      - required @ConditionalOnClass classes not found: org.thymeleaf.spring3.SpringTemplateEngine (OnClassCondition)

   DispatcherServletAutoConfiguration
      - web application classes not found (OnWebApplicationCondition)

   EmbeddedServletContainerAutoConfiguration
      - web application classes not found (OnWebApplicationCondition)

   MultipartAutoConfiguration
      - required @ConditionalOnClass classes not found: javax.servlet.Servlet,org.springframework.web.multipart.support.StandardServletMultipartResolver (OnClassCondition)

   WebMvcAutoConfiguration
      - web application classes not found (OnWebApplicationCondition)

   WebSocketAutoConfiguration
      - required @ConditionalOnClass classes not found: org.springframework.web.socket.WebSocketHandler (OnClassCondition)



org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.entityManagerFactory()] threw exception; nested exception is java.lang.IllegalArgumentException: Unable to find JPA packages to scan, please define a @ComponentScan annotation or disable JpaAutoConfiguration
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:584)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1089)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:984)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:300)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:296)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:973)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:750)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:552)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:293)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:749)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:738)
    at test.builder.BootApp.main(BootApp.java:104)
Caused by: org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.entityManagerFactory()] threw exception; nested exception is java.lang.IllegalArgumentException: Unable to find JPA packages to scan, please define a @ComponentScan annotation or disable JpaAutoConfiguration
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:188)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:573)
    ... 16 more
Caused by: java.lang.IllegalArgumentException: Unable to find JPA packages to scan, please define a @ComponentScan annotation or disable JpaAutoConfiguration
    at org.springframework.util.Assert.notEmpty(Assert.java:268)
    at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.getPackagesToScan(JpaBaseConfiguration.java:109)
    at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.entityManagerFactory(JpaBaseConfiguration.java:76)
    at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerByCGLIB$$7973d544.CGLIB$entityManagerFactory$4()
    at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerByCGLIB$$7973d544$$FastClassByCGLIB$$360fed5a.invoke()
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:334)
    at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration$$EnhancerByCGLIB$$7973d544.entityManagerFactory()
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:166)
    ... 17 more

Pom提取物 -

    org.springframework.boot
    spring-boot-starter-parent
    0.5.0.M6



    
        org.springframework.boot
        spring-boot-starter-data-jpa
    
    
        org.apache.tomcat
        tomcat-jdbc
    
    
        com.microsoft.sqlserver
        sqljdbc4
        4.0
    
    
        ch.qos.logback
        logback-core
        1.0.13
    
    
        ch.qos.logback
        logback-classic
    
    
        org.slf4j
        slf4j-api
    

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