log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.hibernate.exception.JDBCConnectionException: could not load an entity: [vo.customervo#1]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.loader.Loader.loadEntity(Loader.java:1799)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:47)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:41)
at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:2730)
at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:365)
at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:346)
at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:123)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:82)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:862)
at org.hibernate.impl.SessionImpl.immediateLoad(SessionImpl.java:820)
at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:62)
at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:98)
at org.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:158)
at vo.customervo$$EnhancerByCGLIB$$62211fc6.getCustomerName(<generated>)
at com.Dao.getCustomer(Dao.java:27)
at com.Dao.main(Dao.java:92)
Caused by: java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Can't start a cloned connection while in manual transaction mode.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.getImplConnection(Unknown Source)
at com.microsoft.jdbc.base.BaseStatement.setupImplConnection(Unknown Source)
at com.microsoft.jdbc.base.BaseStatement.<init>(Unknown Source)
at com.microsoft.jdbc.base.BasePreparedStatement.<init>(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.prepareStatement(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.prepareStatement(Unknown Source)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:442)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:368)
at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:105)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1561)
at org.hibernate.loader.Loader.doQuery(Loader.java:661)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.loadEntity(Loader.java:1785)
... 15 more

给出你的配置呀

//hibernate.cfg.xml
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools. -->
<hibernate-configuration>

<session-factory>
<property name="myeclipse.connection.profile">test1</property>
<property name="connection.url">
jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=jspdev
</property>
<property name="connection.username">hib</property>
<property name="connection.password">19841024</property>
<property name="connection.driver_class">
com.microsoft.jdbc.sqlserver.SQLServerDriver
</property>
<property name="dialect">
org.hibernate.dialect.SQLServerDialect
</property>
<property name="show_sql">true</property>

<mapping resource="Customer.hbm.xml" />
<mapping resource="Order.hbm.xml" />
</session-factory>

</hibernate-configuration>

//Customer.hbm.xml
<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<!-- DO NOT EDIT: This is a generated file that is synchronized -->
<!-- by MyEclipse Hibernate tool integration. -->
<!-- Created Thu May 25 14:45:26 CST 2006 -->
<hibernate-mapping>

<class name="vo.customervo" table="XIAOXING_CUSTOMER">

<id column="CUSTOMER_ID" name="customerId" type="long" >
<generator class="assigned" />
</id>

<property name="customerName" column="CUSTOMER_NAME"
type="java.lang.String" />
<property name="customerAge" column="CUSTOMER_AGE"
type="java.lang.Long" />
<property name="customerBirth" column="CUSTOMER_BIRTH"
type="java.util.Date" />
<set
name="orders"
cascade="all-delete-orphan"
>
<key column="CUSTOMER_ID"/>
<one-to-many class="vo.ordervo" />
</set>
</class>

</hibernate-mapping>

//Order.hbm.xml
<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<!-- DO NOT EDIT: This is a generated file that is synchronized -->
<!-- by MyEclipse Hibernate tool integration. -->
<!-- Created Thu May 25 14:45:26 CST 2006 -->
<hibernate-mapping>

<class name="vo.ordervo" table="XIAOXING_ORADERS">

<id column="ID" name="id" type="long" >
<generator class="assigned" />
</id>

<property name="orderNumber" column="ORDER_NUMBER"
type="string" >
</property>

<many-to-one
name="customer"
column="CUSTOMER_ID"
class="vo.customervo"
cascade="save-update"
not-null="true" />
</class>

</hibernate-mapping>

非常感谢指点一二，
以前用的时候没有任何问题过了一段时间，
Eclipes升级到3.2，并且以前用的是Oracel数据库
了就出现了这样的问题？？？？？