java - 当我尝试使用 Spring Boot 为 SessionFactory 创建 bean 时，出现无法解析的循环引用

Question

我试图将应用程序与我的数据库连接，但当我尝试运行它时，出现此错误:

Error creating bean with name 'barcodeIngDao': Unsatisfied dependency expressed through method setSessionFactory' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sessionFactory' defined in server.Application: Unsatisfied dependency expressed through method 'sessionFactory' parameter 0; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'sessionFactory': Requested bean is currently in creation: Is there an unresolvable circular reference?

barcodeIngDao 只是一个带有 @Repository 的类，它扩展了 GenericDaoHibernate:

package server.util;

import java.io.Serializable;
import java.lang.reflect.ParameterizedType;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;

import server.exceptions.InstanceNotFoundException;

public class GenericDaoHibernate<E, PK extends Serializable> implements
GenericDao<E, PK> {

    private SessionFactory sessionFactory;

    private Class<E> entityClass;

    @SuppressWarnings("unchecked")
    public GenericDaoHibernate() {
        this.entityClass = (Class<E>) ((ParameterizedType) getClass()
                .getGenericSuperclass()).getActualTypeArguments()[0];
    }

    @Autowired
    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    protected Session getSession() {
        return sessionFactory.getCurrentSession();
    }

    public void save(E entity) {
        getSession().saveOrUpdate(entity);
    }

    public E find(PK id) throws InstanceNotFoundException {
        E entity = (E) getSession().get(entityClass, id);
        if (entity == null) {
            throw new InstanceNotFoundException(id, entityClass.getName());
        }
        return entity;
    }

    public void remove(PK id) throws InstanceNotFoundException {
        getSession().delete(find(id));
    }

}

这是我的Application.java:

package server;

import javax.persistence.EntityManagerFactory;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.orm.jpa.vendor.HibernateJpaSessionFactoryBean;

@SpringBootApplication(exclude=HibernateJpaAutoConfiguration.class)
public class Application {

    @Bean
    public HibernateJpaSessionFactoryBean sessionFactory(EntityManagerFactory emf) {
        HibernateJpaSessionFactoryBean fact = new HibernateJpaSessionFactoryBean();
        fact.setEntityManagerFactory(emf);
        return fact;
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

这是我的 application.properties:

spring.datasource.url=jdbc:postgresql://localhost:5432/AppRecipe?useSSL=false
spring.datasource.username=uibRT
spring.datasource.password=uibRT
spring.datasource.driver-class-name=org.postgresql.Driver
spring.jpa.properties.hibernate.current_session_context_class=org.springframework.orm.hibernate5.SpringSessionContext

我知道我的Application.java在@SpringBootApplication中带有@ComponentScan，它试图为barcodeIngDao创建bean，因为@Repository，并且barcodeIngDao扩展了GenericDaoHibernate，所以它尝试在应用程序时为SessionFactory创建bean .java 仍处于扫描步骤，因此尚未为 SessionFactory 创建 bean。

问题是我不知道在扫描所有类之前是否有办法为 SessionFactory 创建 bean，或者我是否做错了什么并且这不是我之前所说的

编辑如果我尝试这样做:

package server.barcodeing;

import javax.persistence.EntityManagerFactory;

import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import server.util.GenericDaoHibernate;

@Repository("barcodeIngDao")
public class BarcodeIngDaoHibernate extends
        GenericDaoHibernate<BarcodeIng, Long> implements BarcodeIngDao {

    @Autowired 
    private EntityManagerFactory entityManagerFactory;

    public SessionFactory getSessionFactory(){
        return this.entityManagerFactory.unwrap(SessionFactory.class);
    }

}

我收到此错误:

Error creating bean with name 'barcodeIngDao': Unsatisfied dependency expressed through method 'setSessionFactory' parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'org.hibernate.SessionFactory' available: expected at least 1 bean which qualifies as autowire candidate.

编辑2

如果我删除 Application.java 中的 except=HibernateJpaAutoConfiguration.class，我会收到此错误:

Error creating bean with name 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'javax.sql.DataSource' available: expected at least 1 bean which qualifies as autowire candidate.

编辑3

如果我为此替换 Application.java 中的 SessionFactory 方法:

@Bean
public SessionFactory sessionFactory(@Qualifier("entityManagerFactory") EntityManagerFactory emf) {
     return emf.unwrap(SessionFactory.class);
}

我收到此错误:

Error creating bean with name 'barcodeIngDao': Unsatisfied dependency expressed through method 'setSessionFactory' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sessionFactory' defined in server.Application: Unsatisfied dependency expressed through method 'sessionFactory' parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'javax.persistence.EntityManagerFactory' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Qualifier (value=entityManagerFactory)}

编辑4

通过编辑和 edit2 将此依赖项放入 pom 后，我可以运行服务器:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

现在的问题是当我尝试执行请求时出现此错误:

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause java.lang.NullPointerException at server.util.GenericDaoHibernate.getSession(GenericDaoHibernate.java:33)

完整错误:

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause java.lang.NullPointerException
    at server.util.GenericDaoHibernate.getSession(GenericDaoHibernate.java:33)
    at server.util.GenericDaoHibernate.find(GenericDaoHibernate.java:41)
        at server.util.GenericDaoHibernate$$FastClassBySpringCGLIB$$eda6dc96.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:721)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:656)
        at server.recipe.RecipeDaoHibernate$$EnhancerBySpringCGLIB$$1857692b.find(<generated>)
        at server.recipeservice.RecipeServiceImpl.findRecipeById(RecipeServiceImpl.java:26)
        at server.recipeservice.RecipeServiceImpl$$FastClassBySpringCGLIB$$1b7b075.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:721)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:656)
        at server.recipeservice.RecipeServiceImpl$$EnhancerBySpringCGLIB$$14ef69a4.findRecipeById(<generated>)
        at server.controllers.RecipeController.recipeId(RecipeController.java:33)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:745)

Answer 1

您可以尝试在每个 DAO 类中展开 SessionFactory。

这对我来说是工作..

@Autowired private EntityManagerFactory entityManagerFactory;

public SessionFactory getSessionFactory(){
    return this.entityManagerFactory.unwrap(SessionFactory.class);
}

您试图在 setSessionFactory 方法中创建 @autowired 并抛出

通过'setSessionFactory'方法表达的依赖关系不满足

删除它并注释 SessionFactory Bean 定义。

我发现您没有使用 Jpa 自动配置

@SpringBootApplication(exclude=HibernateJpaAutoConfiguration.class)

也删除排除参数。

编辑2:将其添加到您的 MainClass

@PropertySource({"classpath:application.properties"})

可能它没有读取 application.properties 文件。