org.hibernate.InstantiationException：无法实例化抽象类或接口+ google cloud sql

Question

我试图使用hibernate在具体类中保存抽象类的成员。

我的课程

@Entity
@Table(name = "utente2")
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn
(
 name="tipo_collocazione",
 discriminatorType=DiscriminatorType.STRING
)
public abstract class Utente2  implements Serializable{

    @Id
    private Long idUtente;
    @Column(name = "nome")
    private String nome;
    @Column(name = "cognome")
    private String cognome;
    @Column(name = "email")
    private String email;

    public Utente2() {}

    public Long getIdUtente() {
        return idUtente;
    }

    public void setIdUtente(Long idUtente) {
        this.idUtente = idUtente;
    }

    public String getNome() {
        return nome;
    }

    public void setNome(String nome) {
        this.nome = nome;
    }

    public String getCognome() {
        return cognome;
    }

    public void setCognome(String cognome) {
        this.cognome = cognome;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public abstract String getCollocazione();

}

    @Entity
@DiscriminatorValue("INTERNO")
public class UtenteInterno extends Utente2 {

    @Column(name = "collocazione")
    private String collocazione;

    public UtenteInterno(){
        super();
    }

    @Override
    public String getCollocazione() {
        return "Collocazione interna: " + getCollocazione();
    }

    public void setCollocazione(String collocazione) {
        this.collocazione = collocazione;
    }
}

@Entity
@DiscriminatorValue("ESTERNO")
public class UtenteEsterno extends Utente2 {

@Column(name = "collocazione")
private String collocazione;

public UtenteEsterno(){
    super();
}

@Override
public String getCollocazione() {
    return "Collocazione esterna - indirizzo: " + getCollocazione();
}

public void setCollocazione(String collocazione) {
    this.collocazione = collocazione;
}

}

最后的问题是

org.hibernate.InstantiationException: Cannot instantiate abstract class or interface:  : googleTest2.HelloGoogle3.entities.Utente2
at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:114)
at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:136)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.instantiate(AbstractEntityTuplizer.java:737)
at org.hibernate.persister.entity.AbstractEntityPersister.instantiate(AbstractEntityPersister.java:4761)
at org.hibernate.internal.SessionImpl.instantiate(SessionImpl.java:1427)
at org.hibernate.internal.SessionImpl.instantiate(SessionImpl.java:1415)
at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1619)
at org.hibernate.loader.Loader.getRow(Loader.java:1515)
at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:726)
at org.hibernate.loader.Loader.processResultSet(Loader.java:953)
at org.hibernate.loader.Loader.doQuery(Loader.java:921)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:355)
at org.hibernate.loader.Loader.doList(Loader.java:2554)
at org.hibernate.loader.Loader.doList(Loader.java:2540)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2370)
at org.hibernate.loader.Loader.list(Loader.java:2365)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:497)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:387)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:236)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1300)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:103)
at org.hibernate.jpa.internal.QueryImpl.list(QueryImpl.java:573)
at org.hibernate.jpa.internal.QueryImpl.getSingleResult(QueryImpl.java:495)
at org.hibernate.jpa.criteria.compile.CriteriaQueryTypeQueryAdapter.getSingleResult(CriteriaQueryTypeQueryAdapter.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:130)
at org.springframework.orm.jpa.SharedEntityManagerCreator$DeferredQueryInvocationHandler.invoke(SharedEntityManagerCreator.java:362)
at com.sun.proxy.$Proxy38.getSingleResult(Unknown Source)
at org.springframework.data.jpa.repository.query.JpaQueryExecution$SingleEntityExecution.doExecute(JpaQueryExecution.java:202)
at org.springframework.data.jpa.repository.query.JpaQueryExecution.execute(JpaQueryExecution.java:74)
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.doExecute(AbstractJpaQuery.java:97)
at org.springframework.data.jpa.repository.query.AbstractJpaQuery.execute(AbstractJpaQuery.java:88)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:395)
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:373)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodIntercceptor.invoke(CrudMethodMetadataPostProcessor.java:122)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
at com.sun.proxy.$Proxy30.findByNome(Unknown Source)
at googleTest2.HelloGoogle3.controller.HomeController.testDBjpa1_repo(HomeController.java:245)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:130)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:967)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:858)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:843)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:127)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:98)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:502)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

在db中我有表utente2有2条记录。一个带有鉴别器列“INTERNO”，另一个带有消旋器列“ESTERNO”。 例如，如果我使用tomcat运行应用程序，此配置很有效，但现在我想用谷歌应用程序引擎运行它... 在控制器中，我发出了像

这样的请求

Utente2 utente = utenteRepo.findByNome("NameUtente"); 

我有上一个错误......

当我在google app engine + google cloy sql（mysql db）上运行应用程序时，它是否会改变这种hibernate配置？

感谢

Answer 1

问题是我错过了在persistence.xml中映射类和子类。