如果在applicationContext.xml中没有配置bean的属性，那么也会导致空指针异常

Posted 2021-01-19 寒潭渡鹤影

报错如下：

java.lang.NullPointerException
	cn.itcast.action.VisitAction.toAddPage(VisitAction.java:37)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	java.lang.reflect.Method.invoke(Method.java:498)
	ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:870)
	ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1293)
	ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68)
	com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:117)
	com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:108)
	ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1369)
	ognl.ASTMethod.getValueBody(ASTMethod.java:90)
	ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212)
	ognl.SimpleNode.getValue(SimpleNode.java:258)
	ognl.Ognl.getValue(Ognl.java:494)
	ognl.Ognl.getValue(Ognl.java:458)
	com.opensymphony.xwork2.ognl.OgnlUtil$2.execute(OgnlUtil.java:309)
	com.opensymphony.xwork2.ognl.OgnlUtil.compileAndExecute(OgnlUtil.java:340)
	com.opensymphony.xwork2.ognl.OgnlUtil.getValue(OgnlUtil.java:307)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:423)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:287)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:250)
	org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
	org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:253)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
	org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
	org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564)
	org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
	org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
	org.springframework.orm.hibernate5.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:151)
	org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

note The full stack trace of the root cause is available in the Apache Tomcat/8.5.9 logs.

---

Apache Tomcat/8.5.9