Question

当我尝试在LoginController中执行checkCredentials函数时，我得到NullPointerException。我认为问题不在于我的服务实现，而在于DAO实施。但我无法找到导致问题的原因。我不确定问题是否与

有关

@Autowired
private LoginDAO loginDAO;

或

@Repository("loginDAO")

当我提交登录凭据时，我得到以下内容

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)

所以这是root，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;

    }

}

以及messages.properties中的相关条目

NotNull.login.invalidUser = Invalid Username/Password

请帮我解决此问题。

我对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>

创建了这个新例外。

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，这在下面的答案中有所描述。第二个问题实际上与依赖关系有关。

Answer 1

我找到了第二个问题的解决方案（首先由@JBNizet解决）

实际上是关于pom.xml中添加的依赖项，我在这里已经包含了这些依赖项。我做的是我实际上将我的hibernate版本升级到5.1.0然后添加了hibernate-commons-annotations 5.0.1.Final。所以我的依赖关系如下所示。

具体的Hibernate核心将有hibernate-common-annotation，这个缺少类

Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.hibernate.annotations.common.reflection.java.JavaReflectionManager

尝试执行DAO时出现NullPointerException ...无法初始化类..JavaReflectionManager

1 个答案: