我在项目中使用了hibernate模式，并且由于非常简单的数据库操作而获得了随机的表观死锁。

有一个堆栈跟踪：https :
//gist.github.com/knyttl/8999006
–让我感到困惑的是，第一个异常是RollbackException，然后是LockAquisition异常。

问题经常发生在类似的条款上：

@Transactional
public void setLastActivity() {
    User user = em.findById(...);
    user.setLastActivity(new Date());
    em.merge(user);
    em.flush();
}

我很困惑，因为我不知道这是Hibernate，MySQL还是C3P0的问题。

我的Hibernate配置：

            <prop key="hibernate.dialect">${database.dialect}</prop>
            <prop key="hibernate.hbm2ddl.auto">${database.structure}</prop>
            <prop key="hibernate.connection.url">${database.connection}</prop>
            <prop key="hibernate.connection.username">${database.username}</prop>
            <prop key="hibernate.connection.password">${database.password}</prop>
            <prop key="hibernate.connection.driver_class">${database.driver}</prop>
            <prop key="hibernate.connection.shutdown">true</prop>
            <prop key="hibernate.connection.writedelay">0</prop>
            <prop key="hibernate.connection.characterEncoding">UTF-8</prop>
            <prop key="hibernate.connection.charSet">UTF-8</prop>
            <prop key="hibernate.show_sql">${database.show_sql}</prop>
            <prop key="hibernate.format_sql">false</prop>
            <prop key="hibernate.ejb.metamodel.generation">disabled</prop>
            <!-- Use the C3P0 connection pool provider -->
            <prop key="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
            <prop key="hibernate.c3p0.min_size">0</prop>
            <prop key="hibernate.c3p0.max_size">50</prop>
            <prop key="hibernate.c3p0.timeout">120</prop>
            <prop key="hibernate.c3p0.max_statements">0</prop>
            <prop key="hibernate.c3p0.max_statementsPerConnection">0</prop>
            <prop key="hibernate.c3p0.maxStatementsPerConnection">0</prop>
            <prop key="hibernate.c3p0.idle_test_period">120</prop>
            <prop key="hibernate.c3p0.acquire_increment">1</prop>
            <prop key="hibernate.c3p0.numHelperThreads">8</prop>

编辑1：

• 我在上面写过，明显的死锁正在发生-这是错误的，只有“试图获取锁时发现死锁”发生。

编辑2：

这些方法也会发生这种情况-需要使用@Transactional进行注释的那些方法：

@Transactional
public void setLastActivity() {
    em.insertNative("table")
           .values(...)
           .execute();
}