Question

我正在使用JPA来处理JBOSS中的实体。一个实体将在各种事务中被多个线程更新。我在我的实体中添加了@Version属性，并且在更新实体之前我获得了OptimisticLock.I无法处理异常和如果事务失败则重试。

实体

@Entity  
public class DataEntity   
{  
    @Id  
    int id;  
    long count;  
    @Version  
    int versionAttribute;  
     ....  
     ....

更新实体的代码

@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
public void updateEntity()  
{  
     DataEntity d=entityManager.find(DataEntity.class,0,LockModeType.OPTIMISTIC);
     d.setCount(d.getCount()+1);  
}

正如您所看到的，方法updateEntity（）使用TransactionAttributeType.REQUIRES_NEW来创建新事务。这里的事务是容器管理的。所以当抛出OptimisticLockingException时帮助我重试。

在哪里处理异常？ /在哪里写重试逻辑？

Answer 1

如何处理交易边界？

public class SafeHandleInterceptor implements MethodInterceptor {

private final Logger logger = LoggerFactory.getLogger();
private int maxRetryCount = 3;

public void setMaxRetryCount(int maxRetryCount) {
    this.maxRetryCount = maxRetryCount;
}

@Override
public Object invoke(MethodInvocation invocation) throws Throwable {
    int retryCount = 0;
    while (true) {
        try {
            ReflectiveMethodInvocation inv = (ReflectiveMethodInvocation) invocation;
            // clone before proceed, each inv could be proceed only once
            MethodInvocation anotherInvocation = inv.invocableClone();
            return anotherInvocation.proceed();
        } catch (OptimisticException e) {
            if (retryCount++ >= maxRetryCount) {
                throw e;
            } else {
                logger.info("retry for exception:" + e.getMessage(), e);
                continue;
            }
        }
    }
}

}

编织：

<bean id="your original transactional bean name" class="org.springframework.aop.framework.ProxyFactoryBean">
    <property name="target" ref="reference to your original transactional bean" />
    <property name="proxyInterfaces"
        value="your interface" />
    <property name="interceptorNames" value="safeHandleInterceptor" />
</bean>

如何在jboss中的JPA / hibernate中处理OptimisticLockException？

1 个答案: