spring - EntityManager persist() 方法不向数据库插入记录

Question

我在使用 EntityManager.persist(Object) 方法时遇到问题。现在，当我摆脱其他问题时，应用程序可以在没有异常的情况下工作，但对象没有放入我的数据库中。

我的实体类:

@Entity
@Table(name ="Chain")
public class Chain implements Serializable{

@Id
@Column(name = "id")
  private Long id;
@Column(name = "date")
  private Date date;
@Column(name = "name")
  private String name;
//setters and getters
}

我的道课:

@Transactional
@Repository("ChainDao")
public class ChainDaoImpl implements ChainDao{


    private EntityManager em;


    @PersistenceContext
    public void setEntityManager(EntityManager em) {
        this. em = em;
    }

    public int saveChain(Chain chain) {
        chain.setDate(new Date());
        chain.setId((long)44);
        Boolean a;
        em.persist(chain);

        return 222;
    }
}

我的 xml 上下文:

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" >
    <property name="persistenceXmlLocation" value="classpath*:META-INF/persistence.xml"></property></bean>


    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

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

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

和pereistence.xml:

<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">
       <persistence-unit name="sample">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <!-- Scan for annotated classes and Hibernate mapping XML files -->
        <properties>
           <property name="hibernate.archive.autodetection" value="class, hbm"/>
           <property name="hibernate.connection.driver_class" value="org.postgresql.Driver"/>
           <property name="hibernate.connection.url" value="jdbc:postgresql://localhost:5432/database"/>
           <property name="hibernate.connection.username" value="postgres"/>
           <property name="hibernate.connection.password" value="pwd"/>
           <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
           <property name="hibernate.show_sql" value="true"/>
        </properties>
        </persistence-unit>

    </persistence>

有人知道我错过了什么吗？

Answer 1

您是否遇到特定异常？如果您是，了解它是什么会很有帮助。

在 Stackoverflow 上已经有许多类似的问题:

Spring transactional context doesn't persist data

Spring, Hibernate & JPA: Calling persist on entitymanager does not seem to commit to database

这些建议您应该尝试在 em.persist(chain) 之后添加 em.flush()，并更改 @transactional注释

您还应该通过以下行检查是否启用了事务注释:

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

在您的 .xml 配置中