求教Servlet.service() for servlet action threw exception异常
数据库加载失败2012-5-1 1:53:36 org.apache.struts.action.RequestProcessor processException
警告: Unhandled Exception thrown: class java.lang.NullPointerException
2012-5-1 1:53:36 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet action threw exception
java.lang.NullPointerException
at com.wy.dao.ManagerDao.selectOne(ManagerDao.java:86)
at com.wy.webtier.ManagerAction.managerCheck(ManagerAction.java:126)
at com.wy.webtier.ManagerAction.execute(ManagerAction.java:28)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:619)
--------------------编程问答-------------------- 提示说空指针错误。。。。认真看那报什么错。。。。 --------------------编程问答-------------------- 可是前面显示数据库加载失败啊，然后才报的空指针啊 --------------------编程问答-------------------- 没人吗，我每次启动tomcat都会显示数据库加载失败，我是连的sql server2008 --------------------编程问答-------------------- 还有我想问下 要不要配置数据库连接池啊？我是新手，我sql server 2008 for jdbc的驱动包，struts包都加好了，一启动tomcat就出现数据库加载失败，
补充：Java , Java相关
