hibernate异常：exception setting property value with CGLIB，求各位高人帮忙！

异常的详细内容
10:28:16,796  WARN Mappings:75 - duplicate collection role: mypack.Customers.orders
10:28:16,859  WARN Mappings:71 - duplicate class mapping: mypack.Customers
10:28:16,906  WARN Mappings:71 - duplicate class mapping: mypack.Orders
10:28:17,031  WARN Mappings:75 - duplicate collection role: mypack.Customers.orders
10:28:17,031  WARN Mappings:71 - duplicate class mapping: mypack.Customers
10:28:19,640  WARN Configurator:125 - No configuration found. Configuring ehcache from ehcache-failsafe.xml found in the classpath: jar:file:/F:/JAVA/soft/Tomcat/webapps/h4/WEB-INF/lib/ehcache-0.9.jar!/ehcache-failsafe.xml
Hibernate: insert into customers (NAME, SEX, CUSTOMERDESCRIPTION, ID) values (?, ?, ?, ?)
Hibernate: insert into customers (NAME, SEX, CUSTOMERDESCRIPTION, ID) values (?, ?, ?, ?)
Hibernate: select customers0_.ID as ID0_, customers0_.NAME as NAME0_, customers0_.SEX as SEX0_, customers0_.CUSTOMERDESCRIPTION as CUSTOMER4_0_, (select  sum(o.PRICE)  from ORDERS  o where o.CUSTOMER_ID=customers0_.ID) as f2_0_ from customers customers0_ where customers0_.ID=?
Hibernate: select orders0_.CUSTOMER_ID as CUSTOMER4___, orders0_.ID as ID__, orders0_.ID as ID0_, orders0_.ORDER_NUMBER as ORDER_NU2_0_, orders0_.PRICE as PRICE0_, orders0_.CUSTOMER_ID as CUSTOMER4_0_ from orders orders0_ where orders0_.CUSTOMER_ID=?——————执行到这里就报错了！！！！
net.sf.hibernate.PropertyAccessException: exception setting property value with CGLIB (set hibernate.cglib.use_reflection_optimizer=false for more info) setter of mypack.Customers.setTotalPrice
at net.sf.hibernate.persister.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:220)
at net.sf.hibernate.impl.SessionImpl.initializeEntity(SessionImpl.java:2224)
at net.sf.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:319)
at net.sf.hibernate.loader.Loader.doQuery(Loader.java:309)
at net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:138)
at net.sf.hibernate.loader.Loader.loadEntity(Loader.java:941)
at net.sf.hibernate.loader.Loader.loadEntity(Loader.java:961)
at net.sf.hibernate.loader.EntityLoader.load(EntityLoader.java:59)
at net.sf.hibernate.loader.EntityLoader.load(EntityLoader.java:51)
at net.sf.hibernate.persister.EntityPersister.load(EntityPersister.java:413)
at net.sf.hibernate.impl.SessionImpl.doLoad(SessionImpl.java:2131)
at net.sf.hibernate.impl.SessionImpl.doLoadByClass(SessionImpl.java:2001)
at net.sf.hibernate.impl.SessionImpl.load(SessionImpl.java:1930)
at dboperate.OperCustomer.loadCustomer(OperCustomer.java:20)
at dboperate.OperCustomer.test(OperCustomer.java:178)
at stest.Test.doPost(Test.java:25)
at stest.Test.doGet(Test.java:17)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:868)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:663)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:595)
Caused by: net.sf.cglib.beans.BulkBeanException
at mypack.Customers$$BulkBeanByCGLIB$$d6df3405.setPropertyValues(<generated>)
at net.sf.hibernate.persister.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:215)
... 32 more
Caused by: java.lang.NullPointerException
... 34 more