Java - 随着时间的推移打开 hibernate session 的问题

Question

在 Java 应用程序上，我在 Activity 12-24 小时左右收到以下错误消息

org.springframework.transaction.CannotCreateTransactionException: Could not open Hibernate Session for transaction; nested exception is java.lang.NullPointerException
    Caused by: java.lang.NullPointerException
    at sun.reflect.GeneratedMethodAccessor121.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.xxxxxx.persistence.proxy.SessionFactoryProxy$TransactionAwareInvocationHandler.invoke(SessionFactoryProxy.java:322)
    at $Proxy11.openSession(Unknown Source)
    at com.xxxxxx.persistence.proxy.SessionFactoryProxy.openSession(SessionFactoryProxy.java:221)
    at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:425)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:322)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:255)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:102)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:176)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:210)

我将此类与另一个没有此问题的应用程序进行了比较，区别在于 private synchronized SessionFactory getSessionFactory()

我不确定这是否能解决问题，或者如果是其他问题怎么办

private SessionFactory getSessionFactory() {
    SessionFactory sf = sessionFactoryBuilder.getSessionFactory();

    if (!DBConnections.getHibernateSessionsProxyed().containsKey(DBConnections.getCustomer())) {
        Class sfInterface = SessionFactory.class;
        if (sf instanceof SessionFactoryImplementor) {
            sfInterface = SessionFactoryImplementor.class;
        }
        SessionFactory proxy = (SessionFactory) Proxy.newProxyInstance(sfInterface.getClassLoader(), new Class[] { sfInterface },
                new TransactionAwareInvocationHandler(sf));
        DBConnections.addSessionProxyed(proxy);
    }
    return DBConnections.getHibernateSessionProxyed();
}

public Session openSession() throws HibernateException {
    return getSessionFactory().openSession(); //line 221 from the error message
}

public static Map<String, SessionFactory> getHibernateSessionsProxyed() {
    if(hibernateSessionsProxyed == null) {
        hibernateSessionsProxyed = new HashMap<String, SessionFactory>();
    }
    return hibernateSessionsProxyed;
}

public static void addSessionProxyed(SessionFactory session) {
    if(hibernateSessionsProxyed == null) {
        hibernateSessionsProxyed = new HashMap<String, SessionFactory>();
    }
    hibernateSessionsProxyed.put(getCustomer(), session);
}

public TransactionAwareInvocationHandler(SessionFactory target) {
        this.target = target;
    }

提前致谢

Answer 1

似乎是 DBConnections.getHibernateSessionProxyed() 方法中的错误。如果您在静态存储中设置 SessionFactory，则应该同步。