Validator框架出了点小问题

我用struts编写了一个注册的简单页面，用validator框架进行校验，一切都没问题，就是email检测是出问题，说什么找不到类的错误，大家有遇到过的么，能给解答一下么？
java.lang.NoClassDefFoundError: org/apache/oro/text/perl/Perl5Util
at org.apache.commons.validator.EmailValidator.isValid(EmailValidator.java:90)
at org.apache.commons.validator.GenericValidator.isEmail(GenericValidator.java:253)
at org.apache.struts.validator.FieldChecks.validateEmail(FieldChecks.java:1068)
at sun.reflect.GeneratedMethodAccessor174.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.commons.validator.ValidatorAction.executeValidationMethod(ValidatorAction.java:544)
at org.apache.commons.validator.Field.validateForRule(Field.java:796)
at org.apache.commons.validator.Field.validate(Field.java:876)
at org.apache.commons.validator.Form.validate(Form.java:288)
at org.apache.commons.validator.Validator.validate(Validator.java:351)
at org.apache.struts.validator.ValidatorForm.validate(ValidatorForm.java:116)
at org.apache.struts.chain.commands.servlet.ValidateActionForm.validate(ValidateActionForm.java:58)
at org.apache.struts.chain.commands.AbstractValidateActionForm.execute(AbstractValidateActionForm.java:120)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)