} 但错误还是这个 Exception in thread "main" java.lang.NullPointerException at org.springframework.orm.hibernate3.support.HibernateDaoSupport.getSession(HibernateDaoSupport.java:141) at org.my.user.dao.imp.UserDaoImp.findUser(UserDaoImp.java:49) at FindUser.main(FindUser.java:8) 这到底是怎么回事呢
谢谢各位的帮忙 我已经加上事物了 可是错误依旧,还是那个找不到session的错误 这是我加的事务 public List findUser(){ String hql="from User"; Session session = getSession(); Transaction tx = session.beginTransaction(); Query query = session.createQuery(hql); List list = query.list(); tx.commit(); session.close(); return list;
} 但错误还是这个 Exception in thread "main" java.lang.NullPointerException at org.springframework.orm.hibernate3.support.HibernateDaoSupport.getSession(HibernateDaoSupport.java:141) at org.my.user.dao.imp.UserDaoImp.findUser(UserDaoImp.java:49) at FindUser.main(FindUser.java:8) 这到底是怎么回事呢
你要确定,是session为空了,还是你的list为空?即没有查询出来数据!
List users=this.getHibernateTemplate().find("from User");
List users=this.getHibernateTemplate().find("from User");
Transaction tx = session.beginTransaction();
session.save(user);
tx.commit();
session.close(); 这个为何和那个不一样呢?Session session = this.getSession();
Query query = session.createQuery(hql);
List list = query.list();
return list; 你把它改成和上面的一样看看。Session session = getSession();
Transaction tx = session.beginTransaction();
Query query = session.createQuery(hql);
List list = query.list();
tx.commit();
session.close();
return list;
同保存一样
加上 Transaction ta = sess.beginTransaction();
xxxxxx;
xxxxxxxx;
ta.commit();
sess.close()
另外:
你可以在hibernate的配制中加上一个参数 show-sql 设置值为true
然后你可以在控制台查看hibernate生成的sql语句
你把语句复制到查询分析器看有没有返回结果
这样就会很方便了
这是我加的事务
public List findUser(){
String hql="from User";
Session session = getSession();
Transaction tx = session.beginTransaction();
Query query = session.createQuery(hql);
List list = query.list();
tx.commit();
session.close();
return list;
}
但错误还是这个
Exception in thread "main" java.lang.NullPointerException
at org.springframework.orm.hibernate3.support.HibernateDaoSupport.getSession(HibernateDaoSupport.java:141)
at org.my.user.dao.imp.UserDaoImp.findUser(UserDaoImp.java:49)
at FindUser.main(FindUser.java:8)
这到底是怎么回事呢
这是我加的事务
public List findUser(){ String hql="from User";
Session session = getSession();
Transaction tx = session.beginTransaction();
Query query = session.createQuery(hql);
List list = query.list();
tx.commit();
session.close();
return list;
}
但错误还是这个
Exception in thread "main" java.lang.NullPointerException
at org.springframework.orm.hibernate3.support.HibernateDaoSupport.getSession(HibernateDaoSupport.java:141)
at org.my.user.dao.imp.UserDaoImp.findUser(UserDaoImp.java:49)
at FindUser.main(FindUser.java:8)
这到底是怎么回事呢