java.lang.NullPointerException

我在ss2搭建时，遇到的错误，报空指异常：

java.lang.NullPointerExceptioncom.test.action.user.RepairManageAction.readyUpdate(RepairManageAction.java:55)sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)java.lang.reflect.Method.invoke(Method.java:597)com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:453)com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:292)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:255)org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:211)com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:211)com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)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:249)com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:192)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:510)org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:434)

解决办法：

1、检查struts.xml配置文件

2、检查Application.xml配置文件

我这里是这个错误：

struts.xml:

    <action name="rmEdit" class="com.test.action.user.RepairManageAction" method="readyUpdate">    <result>update.jsp</result>    <result name="failed">showList.jsp</result>    </action>

Application.xml:
    <bean id="saveRepairManageAction" class="com.test.action.user.SaveRepairManageAction">          <property name="service" ref="repairManageService"></property>         </bean>         <bean id="rmEdit" class="com.test.action.user.RepairManageAction">           <property name="rmservice" ref="repairManageService"></property>                   </bean>         <bean id="delete" class="com.test.action.user.RepairManageAction">           <property name="rmservice" ref="repairManageService"></property>         </bean>
所以会报空指错误，修改struts.xml里的class="rmRdit"