spring - Spring 存储库中 EntityManager 注入(inject)时出现 java.lang.NullPointerException-6ren

spring - Spring 存储库中 EntityManager 注入(inject)时出现 java.lang.NullPointerException

转载作者：行者123 更新时间：2023-12-02 05:45:47

我是 Spring MVC 的新手。我几天来一直在寻找解决问题的方法，但没有成功。

这是我的堆栈:

jBoss 4.2.3GA 服务器
- 我知道这是一个非常旧的版本，但这就是我现在所限制的。 jBoss 7.1 将在接下来的几个月内被批准在我的组织中使用，但我想让我的研发应用程序在 4.2.3GA 服务器上运行。这意味着我已在/lib 文件夹中添加了所有必需的 jar。
Spring MVC 4.0.2
EJB3.0/JPA 用于持久性
数据库管理系统是 PostgreSQL 9.0.3
我没有使用任何构建/依赖管理工具，例如 Maven 或 Gradle。 Gradle 正在审批过程中，所以这只是时间问题。我现在需要自己管理所有依赖项。

我的项目结构:

源代码
- 基础项目
  - 型号
    - 安全
      - 用户.java
      - 角色.java
      - ...其他与安全相关的实体 bean
  - 存储库
    - 安全
      - UserRepository.java
      - UserRepositoryImpl.java
      - RoleRepository.java
      - RoleRepositoryImpl.java
      - ...其他与安全相关的存储库
  - 服务
    - SecurityService.java
    - SecurityServiceImpl.java
  - 网络
    - Controller
      - UserController.java(典型的 Controller )
    - 配置
      - WebConfig.java(主要 servlet 配置)
      - PersistenceConfig.java(与持久性相关的所有内容。我认为这就是我的问题所在......没有 persistence.xml)

持久化配置.java

package baseproject.web.configuration;

import java.util.Properties;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.lookup.JndiDataSourceLookup;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.Database;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
public class PersistenceConfig {

    @Bean
    public EntityManagerFactory entityManagerFactory() {

        final LocalContainerEntityManagerFactoryBean localContainerEntityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();

        localContainerEntityManagerFactoryBean.setJpaVendorAdapter(jpaVendorAdapter());
        localContainerEntityManagerFactoryBean.setDataSource(dataSource());
        localContainerEntityManagerFactoryBean.setPackagesToScan("baseproject");

        final Properties props = new Properties();
        props.setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
        props.setProperty("hibernate.hbm2ddl.auto", "validate");
        props.setProperty("hibernate.show_sql", "false");
        props.setProperty("hibernate.validator.apply_to_ddl", "false");
        props.setProperty("hibernate.validator.autoregister_listeners", "false");

        localContainerEntityManagerFactoryBean.setJpaProperties(props);

        return localContainerEntityManagerFactoryBean.getObject();
    }

    @Bean
    public HibernateJpaVendorAdapter jpaVendorAdapter() {

        HibernateJpaVendorAdapter hibernateJpaVendorAdapter = new HibernateJpaVendorAdapter();

        hibernateJpaVendorAdapter.setDatabase(Database.POSTGRESQL);
        hibernateJpaVendorAdapter.setDatabasePlatform("org.hibernate.dialect.PostgreSQLDialect");

        return hibernateJpaVendorAdapter;
    }

    @Bean
    public DataSource dataSource() {

        final JndiDataSourceLookup dsLookup = new JndiDataSourceLookup();
        dsLookup.setResourceRef(true);
        DataSource dataSource = dsLookup.getDataSource("java:/dsBaseProject");

        return dataSource;
    }

}

UserRepository.java

package baseproject.repository.security;

import java.util.List;

import baseproject.model.security.User;

public interface UserRepository {

    public User findUserByPk(Integer intUserId);
    public List<User> lstUsers(Integer intSortBy);
    public void addUser(User user);
    public void updateUser(User user);
    public void deleteUser(User user);

}

UserRepositoryImpl.java

package baseproject.repository.security;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import org.springframework.stereotype.Repository;

import baseproject.model.security.User;

@Repository
public class UserRepositoryImpl implements UserRepository {

    @PersistenceContext
    protected EntityManager em;

    public User findUserByPk(Integer intId) {

        User user = null;

        if (intId != null) {
            user = em.find(User.class, intId);
        }

        return user;
    }

public java.util.List<User> lstUsers(Integer intSortBy) {

        List<User> usersList = new ArrayList<User>();

        Query q = em.createNamedQuery("User.lstUsers");

        return usersList;
    }

    public void addUser(User user) {

        user.setIntId(null);
        em.persist(user);
    }

    public void updateUser(User user) {

        User userBd = em.find(User.class, user.getIntId());

        userBd.setStrLastName(user.getStrLastName());
        userBd.setStrFirstName(user.getStrFirstName());
        userBd.setStrUserId(user.getStrUserId());
    }

    public void deleteUser(User user) {

        User userBd = em.find(User.class, user.getIntId());
        em.remove(userBd);
    }
}

SecurityService.java

package baseproject.service;

import java.util.List;

import baseproject.model.security.Method;
import baseproject.model.security.Node;
import baseproject.model.security.Role;
import baseproject.model.security.User;

public interface SecurityService {

    // USERS
    public User findUserByPk(Integer intUserId);
    public User findUserByUserId(String strUserId);

    public void addUser(User user);
    public void updateUser(User user);
    public void deleteUser(User user);

    public List<User> lstUsers(Integer intSortBy);

    public boolean validateUser(User user, String strMethod);

    // ROLES
    public Role findRoleByPk(Integer intRoleId);    

    public List<Role> lstRoles(String strLanguage);

    public void addRole(Role role);
    public void updRole(Role role);
    public void delRole(Role role);


    // NODES
    public List<Node> lstParentNodes();


    // METHODS
    public Method findMethodByPk(Integer intMethodId);
    public Method findMethodByName(String strName);
    public List<String> lstUserAllowedMethods(List<Role> lstRolesAllowed, String strLang, String strRemoteUser);
    public List<Method> lstAllMethods();

}

SecurityServiceImpl.java

package baseproject.service;

import java.util.List;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import baseproject.model.security.Method;
import baseproject.model.security.Node;
import baseproject.model.security.Role;
import baseproject.model.security.User;
import baseproject.repository.security.MethodRepository;
import baseproject.repository.security.NodeRepository;
import baseproject.repository.security.RoleRepository;
import baseproject.repository.security.UserRepository;

@Service
public class SecurityServiceImpl implements SecurityService {

    UserRepository userRepository;
    RoleRepository roleRepository;
    MethodRepository methodRepository;
    NodeRepository nodeRepository;

    @Override
    @Transactional(readOnly = true)
    public User findUserByPk(Integer intUserId) {
        return userRepository.findUserByPk(intUserId);
    }

    @Override
    @Transactional(readOnly = true)
    public User findUserByUserId(String strUserId) {
        return userRepository.findUserByUserId(strUserId);
    }

    @Override
    @Transactional
    public void addUser(User user) {
        userRepository.addUser(user);
    }

    @Override
    @Transactional
    public void updateUser(User user) {
        userRepository.updateUser(user);
    }

    @Override
    @Transactional
    public void deleteUser(User user) {
        userRepository.deleteUser(user);
    }

    @Override
    @Transactional(readOnly = true)
    public List<User> lstUsers(Integer intSortBy) {
        return null;
    }

    @Override
    @Transactional(readOnly = true)
    public boolean validateUser(User user, String strMethod) {
        return false;
    }

    @Override
    @Transactional(readOnly = true)
    public Role findRoleByPk(Integer intRoleId) {
        return null;
    }

    @Override
    @Transactional(readOnly = true)
    public List<Role> lstRoles(String strLanguage) {
        return roleRepository.lstRoles(strLanguage);
    }

    @Override
    @Transactional
    public void addRole(Role role) {
        roleRepository.addRole(role);
    }

    @Override
    @Transactional
    public void updRole(Role role) {

    }

    @Override
    @Transactional
    public void delRole(Role role) {

    }

    @Override
    @Transactional
    public List<Node> lstParentNodes() {
        return nodeRepository.lstParentNodes();
    }

    @Override
    @Transactional
    public Method findMethodByPk(Integer intMethodId) {
        return methodRepository.findMethodByPk(intMethodId);
    }

    @Override
    @Transactional
    public Method findMethodByName(String strName) {
        return methodRepository.findMethodByName(strName);
    }

    @Override
    @Transactional
    public List<String> lstUserAllowedMethods(List<Role> arlRolesAllowed,
            String strLanguage, String strRemoteUser) {
        return methodRepository.lstUserAllowedMethods(arlRolesAllowed, strLanguage, strRemoteUser);
    }

    @Override
    @Transactional
    public List<Method> lstAllMethods() {
        return methodRepository.lstAllMethods();
    }

}

我的结构基于 Spring petclinic 应用程序，该应用程序使用存储库服务设计模式。该问题是在部署时出现的。由于 @Repository 注释，当第一个 Spring 存储库被处理时，我得到了以下堆栈跟踪:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userRepositoryImpl': Injection of persistence dependencies failed; nested exception is java.lang.NullPointerException
        at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessPropertyValues(PersistenceAnnotationBeanPostProcessor.java:356)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
        at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
        at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
        at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3856)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4361)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:790)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:770)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:553)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:296)
        at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:164)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.apache.catalina.core.StandardContext.init(StandardContext.java:5312)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:296)
        at org.jboss.mx.server.RawDynamicInvoker.invoke(RawDynamicInvoker.java:164)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.web.tomcat.service.TomcatDeployer.performDeployInternal(TomcatDeployer.java:301)
        at org.jboss.web.tomcat.service.TomcatDeployer.performDeploy(TomcatDeployer.java:104)
        at org.jboss.web.AbstractWebDeployer.start(AbstractWebDeployer.java:375)
        at org.jboss.web.WebModule.startModule(WebModule.java:83)
        at org.jboss.web.WebModule.startService(WebModule.java:61)
        at org.jboss.system.ServiceMBeanSupport.jbossInternalStart(ServiceMBeanSupport.java:289)
        at org.jboss.system.ServiceMBeanSupport.jbossInternalLifecycle(ServiceMBeanSupport.java:245)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:86)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.system.ServiceController$ServiceProxy.invoke(ServiceController.java:978)
        at $Proxy0.start(Unknown Source)
        at org.jboss.system.ServiceController.start(ServiceController.java:417)
        at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:86)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at $Proxy42.start(Unknown Source)
        at org.jboss.web.AbstractWebContainer.start(AbstractWebContainer.java:466)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
        at org.jboss.mx.interceptor.DynamicInterceptor.invoke(DynamicInterceptor.java:97)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at $Proxy43.start(Unknown Source)
        at org.jboss.deployment.MainDeployer.start(MainDeployer.java:1025)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:819)
        at org.jboss.deployment.MainDeployer.deploy(MainDeployer.java:782)
        at sun.reflect.GeneratedMethodAccessor46.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:155)
        at org.jboss.mx.server.Invocation.dispatch(Invocation.java:94)
        at org.jboss.mx.interceptor.AbstractInterceptor.invoke(AbstractInterceptor.java:133)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.interceptor.ModelMBeanOperationInterceptor.invoke(ModelMBeanOperationInterceptor.java:142)
        at org.jboss.mx.server.Invocation.invoke(Invocation.java:88)
        at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264)
        at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
        at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
        at $Proxy9.deploy(Unknown Source)
        at org.jboss.deployment.scanner.URLDeploymentScanner.deploy(URLDeploymentScanner.java:421)
        at org.jboss.deployment.scanner.URLDeploymentScanner.scan(URLDeploymentScanner.java:610)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.doScan(AbstractDeploymentScanner.java:263)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.loop(AbstractDeploymentScanner.java:274)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.run(AbstractDeploymentScanner.java:225)
    Caused by: java.lang.NullPointerException
        at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.initProxyClassLoader(SharedEntityManagerCreator.java:171)
        at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.<init>(SharedEntityManagerCreator.java:163)
        at org.springframework.orm.jpa.SharedEntityManagerCreator.createSharedEntityManager(SharedEntityManagerCreator.java:135)
        at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.resolveEntityManager(PersistenceAnnotationBeanPostProcessor.java:694)
        at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor$PersistenceElement.getResourceToInject(PersistenceAnnotationBeanPostProcessor.java:655)
        at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:155)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
        at org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor.postProcessPropertyValues(PersistenceAnnotationBeanPostProcessor.java:353)
        ... 99 more

spring-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/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd 
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

    <!-- Auto-balayage de classes dans le contexte / Auto-scan classes within the context -->
    <context:annotation-config />

</beans>

WebConfig.java

package baseproject.web.configuration;

import java.util.Locale;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = { "baseproject" })
public class WebConfig extends WebMvcConfigurerAdapter {

    @Bean
    public ResourceBundleMessageSource messageSource() {

        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();

        String[] strBaseNames = {
                "resources.messages.layout.LayoutResources",
                "resources.messages.global.GlobalResources",
                "resources.messages.welcome.WelcomeResources",
                "resources.messages.user.UserResources",
                "resources.messages.role.RoleResources",
                "resources.messages.profile.ProfileResources"
        };

        messageSource.setUseCodeAsDefaultMessage(true);
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setBasenames(strBaseNames);

        return messageSource;
    }

    @Bean
    public LocaleChangeInterceptor localeChangeInterceptor() {

        LocaleChangeInterceptor result = new LocaleChangeInterceptor();
        result.setParamName("language");

        return result;
    }

    @Bean
    public LocaleResolver localeResolver() {

        SessionLocaleResolver sessionLocaleResolver = new SessionLocaleResolver();
        sessionLocaleResolver.setDefaultLocale(Locale.ENGLISH);

        return sessionLocaleResolver;
    }

    @Override
    public void addInterceptors(InterceptorRegistry interceptorRegistry) {

        interceptorRegistry.addInterceptor(localeChangeInterceptor());
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry resourceHandlerRegistry) {
        resourceHandlerRegistry.addResourceHandler("/static/**").addResourceLocations("/static/");
    }

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
      registry.addViewController("/").setViewName("views/welcome/welcomePage");
    }
}

最后，我的库:

aopalliance-1.0.jar
GlobalLibraries.jar
hibernate-core-4.2.8.Final.jar
hibernate-entitymanager-4.2.8.Final.jar
javax.servlet-api-3.0.1.jar
jcifs-1.3.17.jar
jdo-api-3.0.jar
libs.txt
ognl-3.0.6.jar
openjpa-all-2.2.1.jar
slf4j-api-1.6.6.jar
slf4j-log4j12-1.7.5.jar
spring-aop-4.0.2.RELEASE.jar
spring-aspects-4.0.2.RELEASE.jar
spring-beans-4.0.2.RELEASE.jar
spring-context-4.0.2.RELEASE.jar
spring-context-support-4.0.2.RELEASE.jar
spring-core-4.0.2.RELEASE.jar
spring-expression-4.0.2.RELEASE.jar
spring-framework-bom-4.0.2.RELEASE.jar
spring-instrument-4.0.2.RELEASE.jar
spring-jdbc-4.0.2.RELEASE.jar
spring-jms-4.0.2.RELEASE.jar
spring-ldap-core-2.0.1.RELEASE.jar
spring-ldap-core-tiger-2.0.1.RELEASE.jar
spring-messaging-4.0.2.RELEASE.jar
spring-orm-4.0.2.RELEASE.jar
spring-oxm-4.0.2.RELEASE.jar
spring-security-config-3.2.2.RELEASE.jar
spring-security-core-3.2.2.RELEASE.jar
spring-security-ldap-3.2.3.RELEASE.jar
spring-security-web-3.2.2.RELEASE.jar
spring-test-4.0.2.RELEASE.jar
spring-tx-4.0.2.RELEASE.jar
spring-web-4.0.2.RELEASE.jar
spring-webmvc-4.0.2.RELEASE.jar
spring-webmvc-portlet-4.0.2.RELEASE.jar
spring-websocket-4.0.2.RELEASE.jar
thymeleaf-2.1.2.RELEASE.jar
thymeleaf-spring4-2.1.2.RELEASE.jar

我知道代码很多，但我想提供尽可能多的详细信息。

感谢您的帮助。

最佳答案

我知道这个问题已经存在超过 9 个月了，但我偶然发现了同样的问题并设法解决了它。安德烈·斯特凡 (Andrei Stefan) 的解决方案是朝着正确方向迈出的一步。令人惊讶的是，当您在方法中调用 getObject() 来检索entityManagerFactory时，它会抛出一个NPE，但如果您在entityManagerFactory方法之外调用完全相同的方法，它将起作用。

    @Bean
    public PlatformTransactionManager transactionManager() {
        return new JpaTransactionManager(entityManagerFactory().getObject());
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setDataSource(dataSource());

        HibernateJpaVendorAdapter jpaVendorAdapter = new HibernateJpaVendorAdapter();
        jpaVendorAdapter.setGenerateDdl(true);
        jpaVendorAdapter.setDatabasePlatform("org.hibernate.dialect.H2Dialect");

        factory.setJpaVendorAdapter(jpaVendorAdapter);
        return factory;
    }

    @Bean
    public DataSource dataSource() {
        return new EmbeddedDatabaseBuilder().setType(EmbeddedDatabaseType.H2).build();
    }

关于spring - Spring 存储库中 EntityManager 注入(inject)时出现 java.lang.NullPointerException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/23565175/

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spring - Spring 存储库中 EntityManager 注入(inject)时出现 java.lang.NullPointerException