Validator框架使用时碰到问题
我在用Validator验证框架时碰到发生以下错误：
[ERROR]   DynaValidatorForm   -   org.apache.struts.validator.FieldChecks.validateRequired(java.lang.Object,   org.apache.commons.validator.ValidatorAction,  
org.apache.commons.validator.Field,   org.apache.struts.action.ActionErrors,   javax.servlet.http.HttpServletRequest)   <org.apache.commons.validator.ValidatorException:  
org.apache.struts.validator.FieldChecks.validateRequired(java.lang.Object,   org.apache.commons.validator.ValidatorAction,   org.apache.commons.validator.Field,  
org.apache.struts.action.ActionErrors,   javax.servlet.http.HttpServletRequest)> org.apache.commons.validator.ValidatorException:  
org.apache.struts.validator.FieldChecks.validateRequired(java.lang.Object,   org.apache.commons.validator.ValidatorAction,   org.apache.commons.validator.Field,   org.apache.struts.action.ActionErrors,
javax.servlet.http.HttpServletRequest)
                at   org.apache.commons.validator.ValidatorAction.loadValidationMethod(ValidatorAction.java:627)
                at   org.apache.commons.validator.ValidatorAction.executeValidationMethod(ValidatorAction.java:557)
                at   org.apache.commons.validator.Field.validateForRule(Field.java:827)
                at   org.apache.commons.validator.Field.validate(Field.java:906)
                at   org.apache.commons.validator.Form.validate(Form.java:174)
                at   org.apache.commons.validator.Validator.validate(Validator.java:367)
                at   org.apache.struts.validator.DynaValidatorForm.validate(DynaValidatorForm.java:110)
                at   org.apache.struts.action.RequestProcessor.processValidate(RequestProcessor.java:928)
                at   org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:204)
                at   org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
                at   org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
                at   javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
                at   javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
                at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
                at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
                at   org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
                at   org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
                at   org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)