Question

我试图通过JPA和Spring数据与MySQL数据库进行事务交互。

配置

@Configuration
@EnableJpaRepositories("com.some.models.repositories")
@EnableTransactionManagement
public class MegabotsConfiguration {

    @Bean
    public EntityManagerFactory entityManagerFactory() {

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setJpaProperties(additionalProperties());
        factory.setPackagesToScan(new String[] { "com.datarank.megabots.models.entities", "com.datarank.megabots.models.repositories" });
        factory.setDataSource(dataSource());
        factory.afterPropertiesSet();

        return factory.getObject();
    }

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

    @Bean
    public PlatformTransactionManager transactionManager() {

        JpaTransactionManager txManager = new JpaTransactionManager();
        txManager.setEntityManagerFactory(entityManagerFactory());
        return txManager;
    }

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

    Properties additionalProperties() {
        Properties properties = new Properties();
        properties.setProperty("hibernate.hbm2ddl.auto", "create-drop");
        properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
        return properties;
    }
//...
}

在这里，我试图使用交易：

@Repository
@Scope("prototype")
@Transactional
public class BotWorkQueueRepository {

    @Autowired
    private BotWorkQueueJPARepository botWorkQueueJPARepository; //this is the jparepository referenced in the @EnableJpaRepositories in config

    @PersistenceContext
    private EntityManager entityManager;

    @Transactional
    public synchronized void flagInFlight(final List<BotWorkQueueEntity> botWorkQueueEntities) {
        try {
            //...set a few properties on entities, then
            entityManager.flush(); //Exception thrown here
            entityManager.clear();
        } catch (Exception e) {
            LOGGER.warn("Error making in flight: " + e);
        }
    }    
}

我得到的错误：

javax.persistence.TransactionRequiredException: No transactional EntityManager available

我已尝试在SO中发布此错误的大多数解决方案，但没有成功。

Answer 1

首发一件事，在maven中，如果您使用的是appassembler-maven-plugin，请将以下行添加到POM文件中的plugin.configuration标记中。

<extraJvmArguments>-javaagent:"$REPO"/org/aspectj/aspectjweaver/1.8.5/aspectjweaver-1.8.5.jar</extraJvmArguments>

如果您在IDE中运行，请将以下行添加到VM参数中。

-javaagent:<PATH TO MAVEN REPO>/org/aspectj/aspectjweaver/1.8.5/aspectjweaver-1.8.5.jar

maven repo的路径可能类似于/User/kenny/.m2/repository/。

$REPO将在POM文件中自动解析。

即使配置了

1 个答案: