title: AttributeConverter class registered multiple times when using Eclipse
body: <p>I have an application that used to work fine using both STS and maven command line. 
  After a change in the code, where  a new AttributeConverter was added, it is not working anymore. I'm still able to build and run it using maven command line, but it doesn't run on eclipse. It keep raising the same error:</p>
  
  <pre><code>org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AssertionFailure: AttributeConverter class [class com.mycompany.communication.model.EncryptionConverter] registered multiple times
          at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1080) ~[spring-context-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857) ~[spring-context-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
          at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
          at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
          at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
          at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:134) [spring-boot-1.5.9.RELEASE.jar:1.5.9.RELEASE]
          at com.mycompany.service.RestApplication.main(RestApplication.java:126) [classes/:?]
      Caused by: org.hibernate.AssertionFailure: AttributeConverter class [class com.mycompany.communication.model.EncryptionConverter] registered multiple times
          at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.addAttributeConverter(InFlightMetadataCollectorImpl.java:353) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.addAttributeConverter(InFlightMetadataCollectorImpl.java:386) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl$AttributeConverterManager.addAttributeConverter(AnnotationMetadataSourceProcessorImpl.java:321) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.categorizeAnnotatedClass(AnnotationMetadataSourceProcessorImpl.java:117) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.&lt;init&gt;(AnnotationMetadataSourceProcessorImpl.java:104) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.&lt;init&gt;(MetadataBuildingProcess.java:147) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:141) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
          at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
          at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:360) ~[spring-orm-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:382) ~[spring-orm-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:371) ~[spring-orm-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:336) ~[spring-orm-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
          ...
  </code></pre>
  
  <p>The new AtrributeConverter (EncryptionConverter) is only used in one class. Does someone have an idea what could be wrong here?
  why does it work using the command line (mvn spring-boot:run), but not using eclipse?</p>