在OptimisticLockException之后重试方法时出错-org.postgresql.util.PSQLException:该语句已关闭 [英] Error when retrying method after OptimisticLockException - org.postgresql.util.PSQLException: This statement has been closed

问题描述

我有方法:

public void changeItemName(long id, String nmae) {

    Item item = itemDAO.find(id);
    item.setName(name);

    try {
        itemDAO.save(item);
    } catch (RollbackException | OptimisticLockException | StaleStateException e) {
        logger.warn("Retry method after " + e.getClass().getName());
        itemDAO.clear();
        changeItemName(id, name);
    }
}

首先，我通过设置更高的版本来手动引发OptimisticLockException，因此它会捕获块，清除EntityManager并重试该方法.重试时，对象/实体会刷新并具有正确的版本，但我得到:

First, I manually provoke OptimisticLockException by setting higher version, so it goes to catch block, clears EntityManager and retries the method. When retrying, the object/entity is refreshed and has correct version but I get:

javax.persistence.RollbackException: Error while committing the transaction
at org.hibernate.jpa.internal.TransactionImpl.commit(TransactionImpl.java:86)

Caused by: javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not update: [com.example.Item#1]
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692)

Caused by: org.hibernate.exception.GenericJDBCException: could not update: [com.example.Item#1]
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)

Caused by: org.postgresql.util.PSQLException: This statement has been closed.
at org.postgresql.jdbc2.AbstractJdbc2Statement.checkClosed(AbstractJdbc2Statement.java:2653)

数据库模块(使用Guice 4.1.0):

Database module (using Guice 4.1.0):

public class DbModule extends PrivateModule {

    @Override
    public void configure() {
        install(new JpaPersistModule("persistence-unit").properties(jpaProperties()));

        ...

        Key<PersistFilter> key = Key.get(PersistFilter.class, ExamplePersistenceUnit.class);
        bind(key).to(PersistFilter.class);
        expose(key);
}

保存方法的实现(使用Hibernate 5.1.0.Final):

Save method implementation (using Hibernate 5.1.0.Final):

@Inject
protected EntityManager entityManager;

@Override
public void save(T entity) {
    entityManager.getTransaction().begin();
    entityManager.persist(entity);
    entityManager.getTransaction().commit();
}

为什么会发生?

更新

经过一些调试后，我注意到:

After some debugging, I have noticed that:

• 第一种方法调用-我得到OptimisticLockException/StaleStateException-没关系，这是有意提出并预期的
• 第二种方法调用，重试，我得到Caused by: org.postgresql.util.PSQLException: This statement has been closed-这是意外的
• 第三种方法调用，另一次重试-它运作良好，并成功保存到数据库中

• 1st method invocation - I get OptimisticLockException / StaleStateException - that's ok, it was intentionally raised and expected
• 2nd method invocation, retry, I get Caused by: org.postgresql.util.PSQLException: This statement has been closed - this one was unexpected
• 3rd method invocation, another retry - it works well and saves to the DB successfully

所有3次使用相同的EntityManager entityManager实例.

All 3 times, the same instance of EntityManager entityManager is used.

推荐答案

我也遇到了相同的问题，并且在@Jonathan的评论的帮助下，我通过使用以下方法解决了该问题: @Retryable(include = {ObjectOptimisticLockingFailureException.class，JpaSystemException.class}，backoff = @ Backoff(delay = 100))

I also encountered the same issue, and with the help of @Jonathan's comment, I solved it by using the: @Retryable(include = {ObjectOptimisticLockingFailureException.class, JpaSystemException.class}, backoff=@Backoff(delay = 100))

另请参见常见问题解答: Spring @Retryable-调用时如何记录?

See also good Q&A: Spring @Retryable - how to log when it is invoked?

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