尝试执行 DAO 时出现 NullPointerException ... 无法初始化类 ..JavaReflectionManager
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【中文标题】尝试执行 DAO 时出现 NullPointerException ... 无法初始化类 ..JavaReflectionManager【英文标题】：NullPointerException when trying to execute DAO... Could not initialize class ..JavaReflectionManager 【发布时间】：2017-08-02 12:11:58 【问题描述】：当我尝试在我的 LoginController 中执行 checkCredentials 函数时，我得到了一个 NullPointerException。我认为问题不在于我的服务实现，而在于 DAO 实现。但我无法找到导致问题的原因。我不确定问题是否出在
@Autowired
private LoginDAO loginDAO;
或者
@Repository("loginDAO")
当我提交登录凭据时，我得到以下信息
DEBUG - Returning handler method [public java.lang.String com.accademics.web.controllers.LoginController.checkCredentials(com.accademics.web.models.LoginModel,org.springframework.validation.BindingResult)]
DEBUG - Returning cached instance of singleton bean 'loginController'
inside controller checkCredentials
LoginModel [username=admin, password=password]
service checking login of admin and password
DEBUG - Resolving exception from handler [public java.lang.String com.accademics.web.controllers.LoginController.checkCredentials(com.accademics.web.models.LoginModel,org.springframework.validation.BindingResult)]: java.lang.NullPointerException
DEBUG - Resolving exception from handler [public java.lang.String com.accademics.web.controllers.LoginController.checkCredentials(com.accademics.web.models.LoginModel,org.springframework.validation.BindingResult)]: java.lang.NullPointerException
DEBUG - Resolving exception from handler [public java.lang.String com.accademics.web.controllers.LoginController.checkCredentials(com.accademics.web.models.LoginModel,org.springframework.validation.BindingResult)]: java.lang.NullPointerException
DEBUG - Could not complete request
java.lang.NullPointerException
at com.accademics.data.services.LoginServiceImpl.checkCredentials(LoginServiceImpl.java:18)
at com.accademics.web.controllers.LoginController.checkCredentials(LoginController.java:39)
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 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.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
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)
所以这里是根，applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd">
<bean id="loginService" class="com.accademics.data.services.LoginServiceImpl"/>
</beans>
dispatcher-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
<mvc:annotation-driven />
<context:component-scan base-package="com.accademics.web.controllers"></context:component-scan>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
<bean id="messageSource"
class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="messages"></property>
</bean>
<mvc:resources location="/resources/" mapping="/resources/**"></mvc:resources>
</beans>
student_login.jsp 实际内容部分
<form action='<spring:url value="/student/login"></spring:url>' method="post" autocomplete="on">
<h1>Log in</h1>
<p>
<label for></label>
</p>
<p>
<label for="username" class="uname" > Username </label>
<input id="username" name="username" required="required" type="text" placeholder="Username"/>
</p>
<p>
<label for="password" class="passwd"> Password </label>
<input id="password" name="password" required="required" type="password" placeholder="Password" />
</p>
<p class="keeplogin">
<input type="checkbox" name="saveLogin" id="saveLogin" value="saveLogin" />
<label for="saveLogin">Keep me logged in</label>
</p>
<p class="login button">
<input type="submit" value="Login" />
</p>
</form>
LoginController.java
package com.accademics.web.controllers;
import javax.validation.Valid;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import com.accademics.data.services.LoginService;
import com.accademics.web.models.LoginModel;
@Controller
@RequestMapping("/student")
public class LoginController
@Autowired
public LoginService loginService;
@Autowired
MessageSource messagesource;
@RequestMapping(value="/login", method=RequestMethod.GET)
public String displayLogin(Model model)
return "student_login";
@RequestMapping(value="/login", method=RequestMethod.POST)
public String checkCredentials(@Valid @ModelAttribute LoginModel loginModel, BindingResult result)
System.out.println("inside controller checkCredentials");
if(result.hasErrors())
return "student_login";
System.out.println(loginModel);
boolean userExists = loginService.checkCredentials(loginModel.getUsername(), loginModel.getPassword());
if(userExists)
System.out.println("valid");
return "dashboard";
else
System.out.println("invalid");
result.rejectValue("userName", "NotNull.login.invalidUser");
return "student_login";
LoginServiceImpl.java
package com.accademics.data.services;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.accademics.web.DAO.LoginDAO;
@Service("loginService")
public class LoginServiceImpl implements LoginService
@Autowired
private LoginDAO loginDAO;
@Override
public boolean checkCredentials(String username, String password)
// TODO Auto-generated method stub
System.out.println("service checking login of "+username+" and "+password);
return loginDAO.checkCredentials(username, password);
LoginDAO.java
package com.accademics.web.DAO;
public interface LoginDAO
public boolean checkCredentials(String username, String password);
LoginDAOImpl.java
package com.accademics.web.DAO;
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Repository;
@Repository("loginDAO")
public class LoginDAOImpl implements LoginDAO
@Autowired
private SessionFactory sessionFactory;
protected Session getSession()
return sessionFactory.getCurrentSession();
@Override
public boolean checkCredentials(String username, String password)
System.out.println("Checking login");
//HQL
String hquery = "from student_credentials where student_credentials.username=? and student_credentials.password=?";
boolean userFound = false;
Session session = getSession();
Query query = session.createSQLQuery(hquery);
query.setParameter(0, username);
query.setParameter(1, password);
List list = query.list();
if(!list.isEmpty())
userFound = true;
session.close();
return userFound;
messages.properties 中的相关条目
NotNull.login.invalidUser = Invalid Username/Password
请帮我解决这个问题。
我对我的 dispatcher-servlet 进行了以下更改，并从 applicationContext.xml 中删除了 bean 标记，
<?xml version="1.0" encoding="UTF-8"?>
http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
<mvc:annotation-driven />
<context:component-scan base-package="com.accademics.web" />
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
<bean id="messageSource"
class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="messages"></property>
</bean>
<mvc:resources location="/resources/" mapping="/resources/**"></mvc:resources>
它创建了这个新异常。
ERROR - Context initialization failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'loginController': Unsatisfied dependency expressed through field 'loginService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'loginService': Unsatisfied dependency expressed through field 'loginDAO'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'loginDAO': Unsatisfied dependency expressed through field 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in com.accademics.web.configuration.HibernateConfiguration: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
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:761)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634)
at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682)
at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553)
at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:138)
at javax.servlet.GenericServlet.init(GenericServlet.java:158)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1183)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1099)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:779)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:133)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:108)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'loginService': Unsatisfied dependency expressed through field 'loginDAO'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'loginDAO': Unsatisfied dependency expressed through field 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in com.accademics.web.configuration.HibernateConfiguration: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
... 39 more
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'loginDAO': Unsatisfied dependency expressed through field 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in com.accademics.web.configuration.HibernateConfiguration: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
... 52 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in com.accademics.web.configuration.HibernateConfiguration: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
... 65 more
Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager
at org.hibernate.cfg.Configuration.createReflectionManager(Configuration.java:2547)
at org.hibernate.cfg.Configuration.createReflectionManager(Configuration.java:2543)
at org.hibernate.cfg.Configuration.reset(Configuration.java:298)
at org.hibernate.cfg.Configuration.<init>(Configuration.java:289)
at org.hibernate.cfg.Configuration.<init>(Configuration.java:293)
at org.springframework.orm.hibernate4.LocalSessionFactoryBuilder.<init>(LocalSessionFactoryBuilder.java:140)
at org.springframework.orm.hibernate4.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:343)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)
... 75 more
我真的不明白我的代码有什么问题。
我现在有了解决方案，如下面的答案所述。第二个问题其实和依赖有关。
【问题讨论】：
您的服务 bean 是一部分或根上下文，您没有使用 启用注释，并且您没有配置组件扫描。因此上下文包含一个 bean：xml 文件中定义的服务。 @JBNizet 我已经在我的 dispatcher-servlet.xml 中指定了它们，它是前端控制器。正如您在我的服务器日志中看到的那样，服务 bean 被调用。问题可能出在 DAO 上，但我无法理解。 dispatcher-servlet.xml 定义了子 Web 上下文。它仅扫描 com.accademics.web.controllers 中的组件。因此它只包含包中的控制器，并委托给根上下文以查找其他控制器。但是根上下文只包含服务。 您在 XML 配置中明确定义服务。所以这个服务存在，在spring上下文中注册，因此可以被注入到控制器中。但这是根上下文中定义的唯一 bean，因为没有设置注释配置，没有配置组件扫描，并且 XML 中没有定义其他 bean。 阅读错误信息。它说：没有可用的 'org.hibernate.SessionFactory' 类型的合格 bean。您没有在任何地方定义任何 Sessionfactory 类型的 bean，但 DAO 依赖于它。 docs.spring.io/spring/docs/current/spring-framework-reference/… 【参考方案1】：我找到了第二个问题的解决方案（感谢@JBNizet 解决了第一个问题）
这实际上是关于 pom.xml 中添加的依赖项，我没有将其包含在此处。我所做的是我实际上将我的休眠版本升级到了 5.1.0，然后添加了 hibernate-commons-annotations 5.0.1.Final。所以我的依赖项现在如下所示。
特定的 Hibernate 核心将具有 hibernate-common-annotation 并且缺少类
Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager
【讨论】：
我正在相应地编辑我的帖子，以便遇到类似问题的其他人可能会发现这很有用以上是关于尝试执行 DAO 时出现 NullPointerException ... 无法初始化类 ..JavaReflectionManager的主要内容，如果未能解决你的问题，请参考以下文章
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