Spring@Transactional提交失败；Deby+Eclipselink

Question

<bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource">
    <property name="driverClassName" value="${rwos.dataSource.driverClassName}" />
    <property name="url" value="${rwos.dataSource.url}" />
    <property name="username" value="${rwos.dataSource.user}" />
    <property name="password" value="${rwos.dataSource.password}" />
 </bean>

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

  <bean id="persistenceUnitManager" class="org.springframework.data.jpa.support.MergingPersistenceUnitManager">
        <property name="defaultDataSource" ref="dataSource"/>
  </bean>

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceUnitManager" ref="persistenceUnitManager"/>
        <property name="persistenceUnitName" value="com.retailwave.rwos_rwos-data-pojo_jar_4.0.0PU"/>
  </bean>

  <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"  lazy-init="true">
                <property name="entityManagerFactory" ref="entityManagerFactory"/>
                <property name="dataSource" ref="dataSource" />
  </bean>
    <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>
</beans>

@Singleton
@Component
public class RWTransactionDao {

@PersistenceContext(type = PersistenceContextType.EXTENDED)
private EntityManager em;

 @Override
protected EntityManager getEntityManager() {
    return em;
}

@Transactional
public void createOrderTxns(RWRetailTransaction peTxn, RWRetailTransaction fcTxn) {
    create(peTxn);
    create(fcTxn);
    log.debug("Committed Transaction : {} ", peTxn.displayString());
    log.debug("Committed Transaction : {} ", fcTxn.displayString());
 }

 @Transactional
 public void create(T entity) {
   getEntityManager().persist(entity);
 }

}

@Component
@Path("/")
public class RWTransactionREST {

   @Inject
   private RWTransactionDao rWTransactionDao;

  @POST
  @Produces(MediaType.APPLICATION_JSON)
  @Path("txns/sales")
  public RWResponse createPurchaseTransaction(RWRetailTransaction peTxn, RWRetailTransaction fcTxn) {
    rWTransactionDao.createOrderTxns(peTxn, fcTxn);
    builder.status(RWStatus.OK);
    RWResponse response = builder.build();
    log.info("Returning.. {}", response);
    return response; 
   }

  }

2017-06-14 10:49:51,453 DEBUG [qtp592179046-13] - Committed Transaction : RWRetailTransaction[609, CU_ORD, RTCO-609-17-11193, 2017-06-14 10:49:51.431] 
2017-06-14 10:49:51,453 DEBUG [qtp592179046-13]  - Committed Transaction : RWRetailTransaction[509, CU_ORD, RTCO-509-17-11193, 2017-06-14 10:49:51.444]
2017-06-14 10:49:51,463 INFO  [qtp592179046-13] RWTransactionREST - Returning.. Response[1000:Order has been created successfully, Transaction Id : RTCO-609-17-11193]

2017-06-14 10:51:24,199 ERROR [qtp592179046-16] com.retailwave.rwos.compartment.rest.exception.RWCompartmentRestExceptionMapper - Exception caught at Mapper : Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.4.v20160829-44060b6): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLTransactionRollbackException: A lock could not be obtained within the time requested 

由于此错误，以前的提交被回滚，但它不应该回滚。

不确定导致此回滚的原因。

Answer 1

Derby为INSERT语句锁定单行，保留每行直到提交事务。（如果存在与表关联的索引，则上一个键也会被锁定。）

对于您的问题，我的理解是，您试图在一个事务中向Derby插入两条记录，所以当您执行create(peTxn)；Derby锁定单个行，并保留每一行，直到事务提交[lockA]，然后您尝试执行create(fcTxn)，它将尝试获得另一个单行锁来插入新记录，但实际上事务没有提交，所以锁仍然锁定[lockA]。

所以解决办法是