Spring - Mindestens ein JPA Metamodell muss vorhanden sein

Question

Ich versuche eine Spring Data Anwendung zu erstellen.

Problem: Ausführen des Spring Anwendung ich die Frage bekommen:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: At least one JPA metamodel must be present! 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) 
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) 
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:753) 
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) 
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) 
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:666) 
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:632) 
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:680) 
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:551) 
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:492) 
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136) 
    at javax.servlet.GenericServlet.init(GenericServlet.java:158) 
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1238) 
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1151) 
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:828) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) 
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670) 
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) 
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 
    at java.lang.Thread.run(Unknown Source) 
Caused by: java.lang.IllegalArgumentException: At least one JPA metamodel must be present! 
    at org.springframework.util.Assert.notEmpty(Assert.java:276) 
    at org.springframework.data.jpa.mapping.JpaMetamodelMappingContext.<init>(JpaMetamodelMappingContext.java:52) 
    at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.createInstance(JpaMetamodelMappingContextFactoryBean.java:71) 
    at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.createInstance(JpaMetamodelMappingContextFactoryBean.java:26) 
    at org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet(AbstractFactoryBean.java:134) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574) 

ich für dieses Thema erforscht. Leider habe ich nur eine post gefunden, die mir nicht geholfen hat.

Frage: Warum sollte das jpa-Modell nicht vorhanden sein?

Meine repository Schnittstelle

public interface MachineRepository extends CrudRepository<MachineAnno, Integer>{ 

    List<MachineAnno> findByName(String name); 

} 

Erstellen Bohne des interface's implementation in Dispatcher Servlet-Datei:

<bean id="entityManager" class="com.something.dao.MachineRepositoryImpl"/> 

Meine controller Klasse

@RestController 
public class HomeController { 

    @Autowired 
    private MaschineDAO maschineDAO; 

    @Autowired 
    private final MachineRepository machineRepository; 

    @Autowired 
    HomeController(MachineRepository machineRepository) { 
     this.machineRepository = machineRepository; 
    } 

    @RequestMapping(value = "/machineAnno", method = RequestMethod.GET) 
    Iterable<MachineAnno> readMachines(@PathVariable String userId) { 

     return this.machineRepository.findAll(); 
    } 

} 

Answer 1

Haben u die Folowing Linien in Ihrem Servlet hinzufügen Datei?

<beans:property name="annotatedClasses"> 
    <beans:list> 
     <beans:value>com.something.(packageName of ur entity).MachineAnno</beans:value><!-- Models --> 
    </beans:list> 
</beans:property> 

Hier ist das Beispiel für das Servlet ist,

<?xml version="1.0" encoding="UTF-8"?> 
<beans:beans xmlns="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd 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"> 
<beans:bean 
class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 
<beans:property name="prefix" value="/WEB-INF/views/" /> 
<beans:property name="suffix" value=".jsp" /> 
</beans:bean> 

<context:component-scan base-package="com.app" /> 

<beans:bean id="dataSource" 
class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 
<beans:property name="driverClassName" value="com.mysql.jdbc.Driver" /> 
<beans:property name="url" value="jdbc:mysql://localhost:3306/test" /> 
<beans:property name="username" value="xxx" /> 
<beans:property name="password" value="xxx" /> 
</beans:bean> 

<beans:bean id="sessionFactory" 
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"> 
<beans:property name="dataSource" ref="dataSource" /> 
<beans:property name="annotatedClasses"> 
    <beans:list> 
     <beans:value>com.app.Book</beans:value><!-- Models --> 
<!-- <beans:value>com.com.app.Author 
     </beans:value> --> 
    </beans:list> 
</beans:property> 
<beans:property name="hibernateProperties"> 
    <beans:props> 
     <beans:prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect 
     </beans:prop> 
     <beans:prop key="hibernate.hbm2ddl.auto">update</beans:prop> 
     <beans:prop key="hibernate.show_sql">${hibernate.show_sql}</beans:prop> 
    </beans:props> 
</beans:property> 
</beans:bean> 

<beans:bean id="txManager" 
class="org.springframework.orm.hibernate4.HibernateTransactionManager"> 
<beans:property name="sessionFactory" ref="sessionFactory" /> 
</beans:bean> 

<beans:bean id="persistenceExceptionTranslationPostProcessor" 
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" /> 

<context:component-scan base-package="com.app.books" /> 

<beans:bean id="bookDaoImpl" class="com.app.BookDaoImpl" /><!--daoImpl classes --> 
<beans:bean id="bookServiceImpl" class="com.app.BookServiceImpl" /><!--serviceImpl classes