嚴(yán)重: Servlet.service() for servlet action threw exception
java.lang.NullPointerException
 at org.hibernate.tuple.AbstractEntityTuplizer.createProxy(AbstractEntityTuplizer.java:372)
 at org.hibernate.persister.entity.AbstractEntityPersister.createProxy(AbstractEntityPersister.java:3121)
 at org.hibernate.event.def.DefaultLoadEventListener.createProxyIfNecessary(DefaultLoadEventListener.java:232)
 at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:173)
 at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:87)
 at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:862)
 at org.hibernate.impl.SessionImpl.internalLoad(SessionImpl.java:830)
 at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:266)
 at org.hibernate.type.EntityType.resolve(EntityType.java:303)
 at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:116)
 at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:842)
 at org.hibernate.loader.Loader.doQuery(Loader.java:717)
 at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
 at org.hibernate.loader.Loader.doList(Loader.java:2145)
 at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
 at org.hibernate.loader.Loader.list(Loader.java:2024)
 at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:375)
 at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:308)
 at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:153)
 at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1106)
 at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)
 at org.springframework.orm.hibernate3.HibernateTemplate$29.doInHibernate(HibernateTemplate.java:849)
 at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:372)
 at org.springframework.orm.hibernate3.HibernateTemplate.find(HibernateTemplate.java:840)
 at org.springframework.orm.hibernate3.HibernateTemplate.find(HibernateTemplate.java:832)
 at dao.daoImlHibernate.WordDaoImplHibernate.listAll(WordDaoImplHibernate.java:36)
 at service.serviceImpl.WordServiceImpl.listAll(WordServiceImpl.java:24)
 at com.yourcompany.struts.action.WordAction.listAll(WordAction.java:45)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
 at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
 at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
 at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
 at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
 at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
 at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
 at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
 at java.lang.Thread.run(Unknown Source)


解決方法在從表中 <many-to-one name="usrs" class="model.Usrs" fetch="select" lazy="false">將lazy=“false”
            <column name="usr_id" />
        </many-to-one>