Question

tomcat报错，在线等各位大神解答... 信息如下...

四月 04, 2014 5:50:07 下午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [jsp] in context with path [/ldlyh] threw exception
[javax.el.ELException: Problems calling function 'my:hasPermission'] with root cause
java.lang.NullPointerException
at com.generTech.callqc.aclmanage.service.AclService.hasPermissionByResourceSn(AclService.java:211)
at com.generTech.callqc.aclmanage.service.AclService$$FastClassByCGLIB$$1a1ff7f9.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:688)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:621)
at com.generTech.callqc.aclmanage.service.AclService$$EnhancerByCGLIB$$7bee230b.hasPermissionByResourceSn(<generated>)
at com.generTech.callqc.aclmanage.service.SecurityFunctions.hasPermission(SecurityFunctions.java:25)
at sun.reflect.GeneratedMethodAccessor52.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.apache.el.parser.AstFunction.getValue(AstFunction.java:112)
at org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:189)
at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:985)
at org.apache.jsp.page.frame.left_jsp._jspx_meth_c_005fif_005f48(left_jsp.java:1980)
at org.apache.jsp.page.frame.left_jsp._jspx_meth_c_005fif_005f44(left_jsp.java:1860)
at org.apache.jsp.page.frame.left_jsp._jspService(left_jsp.java:242)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:433)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

Answer 1

在文件left.jsp 中使用到的EL函数, ${my:hasPermission(args) }抛出了NullPointerException 异常,

建议断点调试, 看看与hasPermission相关联的方法执行时哪个对象为 null

可能原因:
1. 在与hasPermission相关联的方法执行时, 方法内部某个变量的引用为null, 而剩余语句调用了此对象的成员
2. 在与hasPermission相关联的方法执行时, 使用到了 与my相关联的类的某个成员对象引用, 但此前并未赋值.
3. 在与hasPermission相关联的方法执行时, 使用了null参数的对象

希望能帮助你

Answer 2

有对象是null 具体在哪我看不出来
at org.apache.jsp.page.frame.left_jsp._jspx_meth_c_005fif_005f48(left_jsp.java:1980)
at org.apache.jsp.page.frame.left_jsp._jspx_meth_c_005fif_005f44(left_jsp.java:1860)
at org.apache.jsp.page.frame.left_jsp._jspService(left_jsp.java:242)
应该在这几个文件里