ssh调用问题

控制台没有报错，下面是网页上的信息，初步分析是UserAction（struts2）中没有成功调用biz,
如果UserAction中直接返回SUCCESS就可以成功跳转，调用biz就像下面这样，希望大家帮忙看看
java.lang.NullPointerException
com.action.UserAction.execute(UserAction.java:37)
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:434)
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:273)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:235)
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:141)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:248)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:49)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:124)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:170)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:170)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:104)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:84)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:208)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:88)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:130)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:143)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:137)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept