java - 创建 EnityManagerFactory 时出现 NullPointerException

Question

我在带有 Hibernate 和 JPA 的 Spring 应用程序中使用了 RepositoryConfig 类，并且得到了 NullPointerException。我对 spring-mvc 应用程序使用了相同的配置文件，没有遇到任何问题。

我已尝试将 Hibernate 降级到早期版本，但问题仍然存在。

RepositoryConfig.java

package com.csms.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.annotation.*;
import org.springframework.core.env.Environment;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.JpaVendorAdapter;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.Database;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;
import java.util.Properties;

@Configuration
@ComponentScan(basePackages = "com.csms")
@PropertySource(value = "classpath:db.properties")
@EnableTransactionManagement
public class RepositoryConfig {

    @Autowired
    private Environment env;

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(env.getProperty("db.driver"));
        dataSource.setUrl(env.getProperty("db.url"));
        dataSource.setUsername(env.getProperty("db.user"));
        dataSource.setPassword(env.getProperty("db.password"));
        return dataSource;
    }

    @Bean
    public JpaVendorAdapter jpaVendorAdapter() {
        HibernateJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
        adapter.setShowSql(true);
        adapter.setGenerateDdl(true);
        adapter.setDatabase(Database.SQL_SERVER);
        adapter.setDatabasePlatform("org.hibernate.dialect.SQLServer2012Dialect");
        return adapter;
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean(
            DataSource dataSource, JpaVendorAdapter jpaVendorAdapter
    ) {
        Properties props = new Properties();
        props.setProperty("hibernate.format_sql", String.valueOf(true));

        LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
        emf.setDataSource(dataSource);
        emf.setJpaVendorAdapter(jpaVendorAdapter);
        emf.setPackagesToScan("com.csms.entities");
        emf.setJpaProperties(props);
        return emf;
    }

    @Bean
    public BeanPostProcessor persistenceTranslation() {
        return new PersistenceExceptionTranslationPostProcessor();
    }

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
        return new JpaTransactionManager(emf);
    }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.team6</groupId>
    <artifactId>c-sms</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.2.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>net.sourceforge.jtds</groupId>
            <artifactId>jtds</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-library</artifactId>
            <version>1.3</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>

    </dependencies>
</project>

堆栈跟踪的一些小细节

SEVERE: Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@60addb54] to prepare test instance [com.csms.dao.PurchaseOrderDAOUnitTest@7813cb11]
        java.lang.IllegalStateException: Failed to load ApplicationContext
            at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
            at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)



 java.lang.IllegalStateException: Failed to load ApplicationContext
            at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)

由以下原因引起:org.springframework.beans.factory.BeanCreationException:创建 com.csms.config.RepositoryConfig 中定义的名称为“entityManagerFactoryBean”的 bean 时出错:调用 init 方法失败；嵌套异常是java.lang.NullPointerException

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactoryBean' defined in com.csms.config.RepositoryConfig: Invocation of init method failed; nested exception is java.lang.NullPointerException
            at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578)

Full Stack traces is on Git and please check here

Answer 1

您需要向 pom.xml 添加 hibernate-entitymanager 依赖项。