Question

我有一个LocalContainerEntityManagerFactoryBean EntityManager个实例。

要快速删除完整表的内容，我想运行以下代码：

@Service
public class DatabaseService {
    @Autowired
    private EntityManager em;

    @Transactional
    public void clear() {
        em.createNativeQuery("TRUNCATE TABLE MyTable").executeUpdate();
    }
}

结果：

ERROR org.springframework.integration.handler.LoggingHandler: javax.persistence.TransactionRequiredException: Executing an update/delete query
    at org.hibernate.jpa.spi.AbstractQueryImpl.executeUpdate(AbstractQueryImpl.java:71)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

如果我做了这个改变：

public void clear() {
    em.getTransaction().begin();
    em.createNativeQuery("TRUNCATE TABLE MyTable").executeUpdate();
}

结果：

ERROR org.springframework.integration.handler.LoggingHandler: java.lang.IllegalStateException: Not allowed to create transaction on shared EntityManager - use Spring transactions or EJB CMT instead
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:245)
    at com.sun.proxy.$Proxy84.getTransaction(Unknown Source)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

我也尝试过spring-data-jpa，但也失败了：

public interface MyRepository extends CrudRepository<MyEntity, Integer> {
    @Query(value = "TRUNCATE TABLE MyTable", nativeQuery = true)
    @Modifying
    public void clear();
}

那么，我如何创建一个事务并在共享的spring上下文中运行truncate？

使用以下命令启动Spring应用程序： SpringApplication.run(AppConfig.class, args);：

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

Answer 1

您应该使用TransactionTemplate对象来强制管理事务：

transactionTemplate.execute(new TransactionCallbackWithoutResult() {
        @Override
        protected void doInTransactionWithoutResult(TransactionStatus status) {
            em.createNativeQuery("TRUNCATE TABLE MyTable).executeUpdate();
        }
    });

要创建TransactionTemplate，只需使用注入PlatformTransactionManager：

transactionTemplate = new TransactionTemplate(platformTransactionManager);

如果您想使用新事务，只需调用

transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW);

Answer 2

作为一种解决方法，我现在使用EntityManager创建了一个新的EMF显式，并手动启动了该事务。

@Autowired
private EntityManagerFactory emf;

public void clearTable() {
    EntityManager em = emf.createEntityManager();
    EntityTransaction tx = em.getTransaction();
    tx.begin();
    em.createNativeQuery("TRUNCATE TABLE MyTable).executeUpdate();
    tx.commit();
    em.close();
}

这可能不太理想，但暂时有效。

Answer 3

Spring Data JPA会自动在事务中运行CRUD方法（无需设置除事务管理器之外的任何内容）。如果要对查询方法使用事务，只需将@Transactional添加到这些：

即可

interface MyRepository extends CrudRepository<MyEntity, Integer> {

  @Transactional
  @Modifying
  @Query(value = "TRUNCATE TABLE MyTable", nativeQuery = true)
  void clear();
}

更一般地说，你在这里声明的内容在逻辑上等同于CrudRepository.deleteAll()，除了它（你的声明）不符合JPA级别的级联。所以我想知道这是你打算做的。如果您正在使用Spring Boot，则应该为您处理激活和事务管理器设置。

如果您想在服务级别使用@Transactional，则需要通过JpaTransactionManager或<tx:annotation-driven />设置@EnableTransactionManagement 和激活基于注释的事务管理{{1}}（看起来激活是您尝试在服务层上创建交易的缺失部分。）

Answer 4

@Transactional批注不应应用于Dao方法，而应应用于服务方法。尽管您的代码说DatabaseService是一项服务，但是通过在服务中插入EntityManger毫无意义。

正确的实现方式是创建如下的Dao。

@Repository
public class DatabaseDao {
    @PersistenceContext
    private EntityManager em;

    public void clear() {
        em.createNativeQuery("TRUNCATE TABLE MyTable").executeUpdate();
    }
}

然后从带有@Transactional批注的服务方法中调用dao方法。

@Service
public class DatabaseService {
    @Autowired
    private DatabaseDao dao;

    @Transactional
    public void clear() {
        dao.clear();
    }
}

还要在您的@EnableTransactionManagement类中添加Configuration

如何在Spring中的共享EntityManager上手动启动事务？

4 个答案: