我使用Kundera作爲JPA與HBase和Java。以下是調用getResultList()方法的方法:在昆德拉使用getResultList()方法時引發Nullpointer異常
@Override
public List<Activity> getAllActivities()
{
em = emf.createEntityManager();
Query q = em.createQuery("select ac from Activity ac");
List<Activity> activities = q.getResultList();
return activities;
}
它引發空指針異常。
Exception in thread "main" java.lang.NullPointerException
at com.impetus.kundera.index.IndexManager.search(IndexManager.java:191)
at com.impetus.kundera.query.LuceneQuery.getResultList(LuceneQuery.java:101)
at com.impetus.activity.dao.ActivityService.getAllActivities(ActivityService.java:100)
at ActivityExample.main(ActivityExample.java:44)
P.S:在HBase的活動表中有6條。
它可能是什麼原因?