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Spring Boot-具有Hibernate的通用DAO层，自动装配DAO实现存在问题

• 问答

我正在尝试通过遵循本教程https://www.baeldung.com/simplifying-the-data-access-layer-with-spring-and-java-generics来实现一种使用postgresql对不同实体实施CRUD操作的通用方法。

以下是DAO层的类：

public interface IGenericDao<T extends Serializable> {

    T findOne(final long id);

    List<T> findAll();

    T create(final T entity);

    T update(final T entity);

    void delete(final T entity);

    void deleteById(final long entityId);
}

public abstract class AbstractHibernateDao<T extends Serializable>
        implements IGenericDao<T> {
    private Class<T> persistentClass;

    private SessionFactory sessionFactory;

    @Autowired
    public AbstractHibernateDao(EntityManagerFactory factory) {
        if (factory.unwrap(SessionFactory.class) == null) {
            throw new NullPointerException("factory is not a hibernate factory");
        }

        sessionFactory = factory.unwrap(SessionFactory.class);

        try {
            persistentClass = ((Class<T>) ((ParameterizedType) getclass()
                    .getGenericSuperclass()).getactualTypeArguments()[0]);
        } catch (Exception e) {

        }
    }

    public T findOne(long id) {

        return (T) getcurrentSession().
                get(persistentClass,id);
    }

    public List findAll() {

        return getcurrentSession().
                createQuery("from " + persistentClass.getName())
                .list();
    }

    public T create(T entity) {
        getcurrentSession().saveOrupdate(entity);

        return entity;
    }

    public T update(T entity) {
        return (T) getcurrentSession().merge(entity);
    }

    public void delete(T entity) {
        getcurrentSession().delete(entity);
    }

    public void deleteById(long entityId) {
        T entity = findOne(entityId);

        delete(entity);
    }

    protected Session getcurrentSession() {
        return sessionFactory.getcurrentSession();
    }
}

@Repository
@Scope(BeanDefinition.SCOPE_PROTOTYPE)
public class GenericHibernateDao<T extends Serializable>
        extends AbstractHibernateDao<T>{

    @Autowired
    public GenericHibernateDao(EntityManagerFactory factory) {
        super(factory);
    }
}

当我尝试从AbstractHibernateDao中的会话工厂获取当前会话时，就会出现问题。 AbstractHibernateDao的两个内部字段均为null（“ persistentClass”和“ sessionFactory”）。为什么会这样？

以下是异常的完整堆栈跟踪：

org.hibernate.hibernateexception: No CurrentSessionContext configured!
    at org.hibernate.internal.SessionFactoryImpl.getcurrentSession(SessionFactoryImpl.java:495) ~[hibernate-core-5.3.12.Final.jar:5.3.12.Final]
    at com.slupov.dao.AbstractHibernateDao.getcurrentSession(AbstractHibernateDao.java:73) ~[classes/:na]
    at com.slupov.dao.AbstractHibernateDao.findAll(AbstractHibernateDao.java:47) ~[classes/:na]
    at com.slupov.dao.AbstractHibernateDao$$FastClassBySpringCGLIB$$11991ea4.invoke(<generated>) ~[classes/:na]
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodinvocation.invokeJoinpoint(CglibAopProxy.java:750) ~[spring-aop-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodinvocation.proceed(ReflectiveMethodinvocation.java:163) ~[spring-aop-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodinvocation.proceed(ReflectiveMethodinvocation.java:186) ~[spring-aop-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) ~[spring-aop-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at com.slupov.dao.GenericHibernateDao$$EnhancerBySpringCGLIB$$f7c8fc19.findAll(<generated>) ~[classes/:na]
    at com.slupov.controllers.FileDownloadController.downloadPDFResource(FileDownloadController.java:41) ~[classes/:na]
    at sun.reflect.NativeMethodaccessorImpl.invoke0(Native Method) ~[na:1.8.0_201]
    at sun.reflect.NativeMethodaccessorImpl.invoke(NativeMethodaccessorImpl.java:62) ~[na:1.8.0_201]
    at sun.reflect.DelegatingMethodaccessorImpl.invoke(DelegatingMethodaccessorImpl.java:43) ~[na:1.8.0_201]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_201]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:798) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:94) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.10.RELEASE.jar:5.1.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_201]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_201]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.26.jar:9.0.26]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_201]

似乎找不到上下文，但是我已经在application.properties中明确指出了该上下文：

spring.datasource.driver-class-name=org.postgresql.Driver

spring.datasource.url=jdbc:postgresql://localhost:5432/SlupovPersonal?useSSL=false
spring.datasource.username=postgres
spring.datasource.password=Sigma255!
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQL9Dialect
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true
spring.jpa.properties.show_sql=true

spring.jpa.properties.current_session_context_class=thread

spring.jpa.properties.hbm2ddl.auto=update

spring.datasource.dbcp2.initial-size=5
spring.datasource.dbcp2.maxTotal=20
spring.datasource.dbcp2.maxIdle=10
spring.datasource.dbcp2.minIdle=5
spring.datasource.dbcp2.maxWaitMillis=-1

spring.datasource.validation-query=SELECT 1

这是我的项目的https://github.com/Slupov/SlupovPersonal/tree/dev/HibernateConnection的github存储库。 请注意，问题出在dev / HibernateConnection分支上！

如何解决此问题？

qq820066128 回答：Spring Boot-具有Hibernate的通用DAO层，自动装配DAO实现存在问题
暂时没有好的解决方案，如果你有好的解决方案，请发邮件至：iooj@foxmail.com
hibernatejavaspringspring-boot
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