title: What is correct workaround when updating entities in jhipster?
body: <p>I have a modelio UML class model. I have been updating it all the time and after that I run jhipster-uml .xmi to regenerate entities. I always ended up to error messages. I tried to delete from -jhipster files the entity.json files but it doesn't help. So could you tell me what is correct workaround to update entities during the development? I tried to run maven:diff task as well, but no luck.</p>
  
  <p><strong>EDIT:</strong> </p>
  
  <p>I created a new jhipster app and created entities from modelio UML class model. Everything is working fine. Then I just added one attribute to my model and regenerate the entity from xmi-file and everything os broken again.</p>
  
  <p>My workflow was:
  1) save uml model as xmi-file
  2) Run jhipster-uml ac2.xmi -paginate
  3) Compile my app in intellijIdea
  4) run maven task:  mvn compile liquibase:diff to create a new changelog
  5) run application
  6) Watch the error messages:</p>
  
  <pre><code>1 change sets check sum
        classpath:config/liquibase/changelog/20150828220237_added_entity_Employee.xml::20150828220237::jhipster is now: 7:dd10f74a01a95b4e48c592e796a1d352
  </code></pre>
  
  <hr>
  
  <p>Part of the error:</p>
  
  <pre><code>[DEBUG] com.acontrol.config.DatabaseConfiguration - Configuring Datasource
  [DEBUG] com.acontrol.config.DatabaseConfiguration - Configuring Liquibase
  [ERROR] org.springframework.boot.context.embedded.tomcat.TomcatStarter - Error starting Tomcat context: org.springframework.beans.factory.BeanCreationException
  [WARN] org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext - Exception encountered during context initialization - cancelling refresh attempt
  org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:133) [spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:474) ~[spring-context-4.1.7.RELEASE.jar:4.1.7.RELEASE]
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) [spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686) [spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:320) [spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at com.acontrol.Application.main(Application.java:72) [classes/:na]
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_05]
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_05]
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_05]
      at java.lang.reflect.Method.invoke(Method.java:483) ~[na:1.8.0_05]
      at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140) [idea_rt.jar:na]
  Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:98) ~[spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.&lt;init&gt;(TomcatEmbeddedServletContainer.java:75) ~[spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:378) ~[spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:155) ~[spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:157) [spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:130) [spring-boot-1.2.5.RELEASE.jar:1.2.5.RELEASE]
      ... 10 common frames omitted
  Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire method: public void org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration.setFilterChainProxySecurityConfigurer(org.springframework.security.config.annotation.ObjectPostProcessor,java.util.List) throws java.lang.Exception; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'securityConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.security.core.userdetails.UserDetailsService com.acontrol.config.SecurityConfiguration.userDetailsService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDetailsService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.acontrol.repository.UserRepository com.acontrol.security.UserDetailsService.userRepository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userRepository': Cannot create inner bean '(inner bean)#5550ca83' of type [org.springframework.orm.jpa.SharedEntityManagerCreator] while setting bean property 'entityManager'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5550ca83': Cannot resolve reference to bean 'entityManagerFactory' while setting constructor argument; nested exception is 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 javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory
      at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.1.7.RELEASE.jar:4.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1210) ~[spring-beans-4.1.7.RELEASE.jar:4.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) ~[spring-beans-4.1.7.RELEASE.jar:4.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) ~[spring-beans-4.1.7.RELEASE.jar:4.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303) ~[spring-beans-4.1.7.RELEASE.jar:4.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[s
  </code></pre>