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问题：

空指针异常

倪炎彬
2023-03-14

我已经更新了我的项目中的一些依赖关系之后，我的Hibernate配置类显示Nullpointerx的。

我将SpringDataJPA存储库与hibernate一起使用，已经超过24小时了，仍然没有找到任何关于小问题的适当解决方案。

我已经尝试过的一些解决方案：-

  1. 使用@bean（name=“entityManagerFactory”）提供bean名称

我面临的问题

19:29:11.756 [main] ERROR o.s.web.context.ContextLoader - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in com.carportal.config.HibernateConfig: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean]: Factory method 'entityManagerFactory' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:656)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:484)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1108)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:401)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:292)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:103)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4683)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5146)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
    at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
    at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
    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.apache.catalina.startup.Bootstrap.start(Bootstrap.java:343)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:474)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean]: Factory method 'entityManagerFactory' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651)
    ... 45 common frames omitted
Caused by: java.lang.NullPointerException: null
    at com.carportal.config.HibernateConfig.additionalProperties(HibernateConfig.java:74)
    at com.carportal.config.HibernateConfig.entityManagerFactory(HibernateConfig.java:46)
    at com.carportal.config.HibernateConfig$$EnhancerBySpringCGLIB$$f78c3ea8.CGLIB$entityManagerFactory$3(<generated>)
    at com.carportal.config.HibernateConfig$$EnhancerBySpringCGLIB$$f78c3ea8$$FastClassBySpringCGLIB$$e9aea17b.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331)
    at com.carportal.config.HibernateConfig$$EnhancerBySpringCGLIB$$f78c3ea8.entityManagerFactory(<generated>)
    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.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 46 common frames omitted

波姆。xml文件

<properties>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <spring.version>5.2.6.RELEASE</spring.version>
        <springdatajpa.version>2.2.6.RELEASE</springdatajpa.version>
        <spring.security.version>5.3.1.RELEASE</spring.security.version>
        <mysqlconnector.version>8.0.20</mysqlconnector.version>
        <hibernate.version>5.4.15.Final</hibernate.version>
        <hibernate.validator>6.1.5.Final</hibernate.validator>
</properties>
    <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysqlconnector.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-hikaricp</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-ehcache</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-java8</artifactId>
            <version>${hibernate.version}</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>${hibernate.validator}</version>
        </dependency>
        <dependency>
            <groupId>javax.cache</groupId>
            <artifactId>cache-api</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.ehcache</groupId>
            <artifactId>ehcache</artifactId>
            <version>3.8.1</version>
        </dependency>
        <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.27.0-GA</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>${springdatajpa.version}</version>
        </dependency>

配置类

@Configuration
@EnableTransactionManagement
@PropertySource({ "classpath:db.properties" })
@ComponentScan({ "com.carportal.model", "com.carportal.repository", "com.carportal" })
@EnableJpaRepositories(basePackages = "com.carportal.repository")
public class HibernateConfig {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private static Environment env;

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() throws NamingException {
        logger.debug("Local Container Entity Manager Factory Bean");
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan("com.carportal");
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalProperties());
        return em;
    }

    @Bean
    public DataSource dataSource() throws NamingException {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3306/carportadb");
        dataSource.setUsername("sam");
        dataSource.setPassword("root");
        return dataSource;
    }

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

    @Bean
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
        return new PersistenceExceptionTranslationPostProcessor();
    }

    Properties additionalProperties() {
        Properties hibernateProperties = new Properties();
        hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
        hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
        hibernateProperties.setProperty("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
        hibernateProperties.setProperty("hibernate.cache.region.factory_class",
                env.getProperty("hibernate.cache.region.factory_class"));
        hibernateProperties.setProperty("hibernate.cache.use_query_cache",
                env.getProperty("hibernate.cache.use_query_cache"));
        hibernateProperties.setProperty("hibernate.dialect.storage_engine",
                env.getProperty("hibernate.dialect.storage_engine"));

        /*
         * hibernateProperties.put(CONNECTION_PROVIDER,
         * env.getProperty("hibernate.connection.provider_class"));
         */

        hibernateProperties.setProperty("hibernate.cache.use_second_level_cache",
                env.getProperty("hibernate.cache.use_second_level_cache"));

        return hibernateProperties;
    }

}

db。性质

# jdbc
jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/carportadb
jdbc.user=sam
jdbc.pass=root


# hibernate
hibernate.dialect=org.hibernate.dialect.MySQLInnoDBDialect
hibernate.dialect.storage_engine=InnoDBStorageEngine
hibernate.show_sql=true
hibernate.hbm2ddl.auto=create

hibernate.cache.region.factory_class=org.hibernate.cache.ehcache.EhCacheRegionFactory
#hibernate.connection.provider_class=org.hibernate.hikaricp.internal.HikariCPConnectionProvider
hibernate.dialect.storage_engine=InnoDBStorageEngine
hibernate.cache.use_second_level_cache=false
hibernate.cache.use_query_cache=false

共有1个答案

公羊宇定
2023-03-14

您的Stackstrace表示您的方法com.carportal.config.HibernateConfig.additionalProperties（）中有一个NullPointerExc0019。

这里您尝试使用自动生成字段"env"。

据我所知，无法自动关联静态字段（另请参见https://stackoverflow.com/a/1019053/13454816).试着清除场地上的静电干扰。

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