java - EntityManager 不能使用 persist 将元素保存到数据库

Question

我遇到了使用 EntityManager 将元素持久化到数据库的问题。根据我找到的答案，我在我的 DaoJpa 中尝试了这 4 种方法来做这样的事情，但仍然失败了。这里附上我尝试过的四种方式:

Controller 部分的代码:

   @Transactional 
   SmartProduct smartProduct = new SmartProduct();
            smartProduct.setName("Dove Soap");
            smartProductDao.persist(smartProduct);

1. 道杰帕:

 @Transactional
 public void persist(SmartProduct smartProduct) {
            entityManager.persist(smartProduct);

不起作用!

2.

@Transactional
public void persist(SmartProduct smartProduct) {
entityManager.persist(smartProduct);
entityManager.flush();

Exception I got: no transaction is in progress

3.

@Transactional
public void persist(SmartProduct smartProduct) {
EntityTransaction emTransaction = entityManager.getTransaction();
        emTransaction.begin();  
        entityManager.persist(smartProduct);
        emTransaction.commit();
        entityManager.close();

Exception I got: Not allowed to create transaction on shared EntityManager - use Spring transactions or EJB CMT instead

4.

@Transactional
public void persist(SmartProduct smartProduct) {
                    EntityManagerFactory emf = Persistence.createEntityManagerFactory("persistenceUnit");
                EntityManager em = emf.createEntityManager();
                EntityTransaction etx = em.getTransaction();
                etx.begin();
                em.persist(smartProduct);
                etx.commit();
                em.close();
                emf.close();

Exception I got: The application must supply JDBC connections

有人可以帮我解决这个问题吗？提前谢谢了!

非常感谢 JustinKSU 的帮助。我在 Spring 上下文中添加注释，然后它解决了!这是我的 Spring 上下文的先前版本:

<bean class="org.springframework.orm.jpa.JpaTransactionManager" id="transactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

    <tx:annotation-driven mode="aspectj" transaction-manager="transactionManager" />

    <bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
        <property name="persistenceUnitName" value="persistenceUnit" />
        <property name="dataSource" ref="dataSource" />
    </bean>

添加后

<tx:annotation-driven />

有效:

<tx:annotation-driven />
    <bean class="org.springframework.orm.jpa.JpaTransactionManager" id="transactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

    <tx:annotation-driven mode="aspectj" transaction-manager="transactionManager" />

    <bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
        <property name="persistenceUnitName" value="persistenceUnit" />
        <property name="dataSource" ref="dataSource" />
    </bean>

Answer 1

要在 Spring 上下文中启用 @Transactional，您应该具备以下条件:

适合您的 Spring 版本:

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

启用注释:

<tx:annotation-driven />

声明您的事务管理器注入(inject)您的实体管理器:

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>