我的 Webproject 代码部署在 weblogic 12c 服务器上。每当我调用 Home.jsp 页面时，该页面又调用了一个 servlet，它会给出以下错误。然而，有时 Home.jsp 页面会加载，有时会抛出错误。
Home.jsp 调用 Home Servlet，然后 diospatcher 重定向
Pas[ACTIVE] ExecuteThread: '16' for queue: 'weblogic.kernel.Default (self-tuning)' 10/12/15 01:39:51 ERROR com.att.first.firststatusreports.servlet.HomeServlet doGet - Error occured!
java.lang.NullPointerException
at com.sun.faces.context.ApplicationMap.get(ApplicationMap.java:97)
at com.sun.faces.application.ApplicationAssociate.getInstance(ApplicationAssociate.java:247)
at com.sun.faces.application.ApplicationAssociate.getCurrentInstance(ApplicationAssociate.java:277)
at com.sun.faces.el.ManagedBeanELResolver.getBeanManager(ManagedBeanELResolver.java:228)
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:235)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at com.sun.faces.el.ChainTypeCompositeELResolver.getValue(ChainTypeCompositeELResolver.java:94)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:188)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:188)
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:103)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:224)
at weblogic.servlet.jsp.ELHelper.evaluate(ELHelper.java:32)
at jsp_servlet.__home._jspService(__home.java:156)
at weblogic.servlet.jsp.JspBase.service(JspBase.java:34)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:242)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:216)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:132)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:352)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:235)
at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:567)
at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:263)
at com.att.first.firststatusreports.servlet.HomeServlet.doGet(HomeServlet.java:64)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:844)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:242)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:216)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:132)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:352)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:235)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3284)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3254)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2163)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2089)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2074)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1512)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:254)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)