我在hybernate新手,我有以下异常艰难:打开会话时发生Hibernate异常。我怎样才能调试呢?
异常在线程“AWT-EventQueue的 - 0” org.hibernate.HibernateException:非法尝试将 代理有两个打开的会话关联
我试着删除一个对象(一个订单)时得到这个。
我的设置/代码:
Order.hbm.xml
<hibernate-mapping>
<class name="com.database.entities.Order" table="ORDERS">
<id name="orderId" type="java.lang.Long">
<column name="ORDERID" />
<generator class="identity" />
</id>
<property name="product" type="java.lang.String">
<column name="SHIP" />
</property>
<property name="orderDate" type="java.util.Date">
<column name="ORDERDATE" />
</property>
<property name="quantity" type="java.lang.Integer">
<column name="QUANTITY" />
</property>
<many-to-one name="customer" class="com.database.entities.Customer" fetch="join">
<column name="CUSTOMERID"/>
</many-to-one>
<many-to-one name="associate" column="ASSOCIATEID" class="com.database.entities.Employee" fetch="join">
</many-to-one>
</class>
</hibernate-mapping>
会话持有人:
public class DBSession {
private static SessionFactory sessionFactory;
static{
Configuration cfg = new Configuration();
sessionFactory = cfg.configure().buildSessionFactory();
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
public static void shutdown() {
getSessionFactory().close();
}
}
以及相关的DAO都延长了以下内容:
public abstract class GenericDAO<T, ID extends Serializable> implements GenericDAOIF<T, ID> {
private Class<T> persistentClass;
private Session session;
public Session getSession() {
if(session == null || !session.isOpen()){
session = DBUtil.getSessionFactory().openSession();
}
return session;
}
public void setSession(Session session) {
this.session = session;
}
@SuppressWarnings("unchecked")
@Override
public T findById(ID id, boolean lock) {
T entity;
if(lock)
entity = (T) getSession().load(getPersistentClass(), id, LockMode.UPGRADE);
else
entity = (T) getSession().load(getPersistentClass(), id);
return entity;
}
@Override
public T makePersistent(T entity) {
getSession().beginTransaction();
getSession().saveOrUpdate(entity);
flush();
getSession().getTransaction().commit();
return entity;
}
@Override
public void flush() {
getSession().flush();
}
@Override
public void clear() {
getSession().clear();
}
@Override
public void makeTransient(T entity) {
getSession().getTransaction().begin();
getSession().delete(entity);
getSession().getTransaction().commit();
}
}
虽然所有的其他查询工作(例如,插入/选择其他实体和顺序),当我尝试删除我得到GenericDAO的代码的以下部分以下异常命令:
public void makeTransient(T entity) {
getSession().getTransaction().begin();
getSession().delete(entity);//--> Exception here
getSession().getTransaction().commit();
}
的异常堆栈跟踪:
Exception in thread "AWT-EventQueue-0" org.hibernate.HibernateException: illegally attempted to associate a proxy with two open Sessions
at org.hibernate.proxy.AbstractLazyInitializer.setSession(AbstractLazyInitializer.java:126)
at org.hibernate.engine.StatefulPersistenceContext.reassociateProxy(StatefulPersistenceContext.java:573)
at org.hibernate.engine.StatefulPersistenceContext.unproxyAndReassociate(StatefulPersistenceContext.java:618)
at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:89)
at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:73)
at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:956)
at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:934)
at com.dao.GenericDAO.makeTransient(GenericDAO.java:100)
at com.ui.panels.AdminDBPanel$11.actionPerformed(AdminDBPanel.java:414)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
只有在我删除订单时才会发生这种情况(这就是为什么我只发布了部分代码)。
我不明白这个例外的含义。
但谷歌搜索我想它做了以下不工作:
1)会议合并:
@Override
public void makeTransient(T entity) {
getSession().merge(entity);
getSession().getTransaction().begin();
getSession().delete(entity);
getSession().getTransaction().commit();
}
2)关闭会话并重新打开:
public Session getSession() {
if(session == null || !session.isOpen()){
session = DBUtil.getSessionFactory().openSession();
}
else{
session.close();
session = DBUtil.getSessionFactory().openSession();
}
return session;
}
我坚持关于如何调试这个。
任何投入是非常值得欢迎的
UPDATE:
额外的信息:
员工映射:
<hibernate-mapping>
<class name="com.database.entities.Employee" table="ASSOCIATE">
<id name="assosiateId" type="java.lang.Long">
<column name="ASSOCIATEID" />
<generator class="identity" />
</id>
<property name="firstName" type="java.lang.String" not-null="true">
<column name="FIRSTNAME" />
</property>
<property name="lastName" type="java.lang.String" not-null="true">
<column name="LASTNAME" />
</property>
<property name="userName" type="java.lang.String" not-null="true">
<column name="USERNAME" />
</property>
<property name="password" type="java.lang.String" not-null="true">
<column name="PASSWORD" />
</property>
<set name="orders" table="ORDERS" inverse="true" cascade="all" lazy="true">
<key>
<column name="ASSOCIATEID" />
</key>
<one-to-many class="com.database.entities.Order" />
</set>
</class>
</hibernate-mapping>
<hibernate-mapping>
<class name="com.database.entities.Customer" table="CUSTOMER">
<id name="customerId" type="java.lang.Long">
<column name="CUSTOMERID" />
<generator class="identity" />
</id>
<property name="customerName" type="java.lang.String">
<column name="CUSTOMERNAME" />
</property>
<set name="orders" table="ORDERS" inverse="true" cascade="all" lazy="true">
<key>
<column name="CUSTOMERID" />
</key>
<one-to-many class="com.database.entities.Order" />
</set>
</class>
</hibernate-mapping>
客户映射:
<hibernate-mapping>
<class name="com.database.entities.Customer" table="CUSTOMER">
<id name="customerId" type="java.lang.Long">
<column name="CUSTOMERID" />
<generator class="identity" />
</id>
<property name="customerName" type="java.lang.String">
<column name="CUSTOMERNAME" />
</property>
<set name="orders" table="ORDERS" inverse="true" cascade="all" lazy="true">
<key>
<column name="CUSTOMERID" />
</key>
<one-to-many class="com.database.entities.Order" />
</set>
</class>
</hibernate-mapping>
个
OrderDAO:
public class OrderDAO extends GenericDAO<Order, Long> implements OrderDAOIF {
@Override
public void addOrder(Order order, Customer customer, Associate associate) {
Session session = getSession();
Transaction tx = session.beginTransaction();
order.setAssociate(associate);
order.setCustomer(customer);
session.saveOrUpdate(order);
tx.commit();
session.close();
}
@Override
public void updateOrderStatus(String status, Long orderId) {
Order order = findById(orderId, false);
order.setOrderState(status);
Session session = getSession();
Transaction tx = session.beginTransaction();
session.saveOrUpdate(order);
tx.commit();
session.close();
}
}
启动异常的代码:
Order order = getFactory().getOrderDAO().findById(Long.valueOf(orderId), false);
getFactory().getOrderDAO().makeTransient(order);//--> Exception thrown here
你在哪里调用函数删除订单? – Zohaib
+1在这个问题的细节 –