如何实现struts的validator框架？

手动:
   public class myForm extends ActionForm 
   {
    public ActionErrors validate()
    {
actionErrors.add(ActionErrors.GLOBAL_MESSAGE,new ActionMessage(”properties中的键名”));
    }
   } 
   struts-config.xml中修改action的标签validate=true
    input=”错误页面”
   如果validate方法中的ActionErrors不为空且size>0时
   会回到input页面。
  自动
   public class myForm extends ValidateForm 
   {
    不能覆盖validate方法。
    //public void validate()
    //{
 
    //}
   } 
   在struts-config.xml文件中加入插件
     <plug-in className=”org.apache.struts.validator.ValidatorPlugIn”>
         <set-property property=”pathnames” value=”/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml” />
      </plug-in>
 修改validation.xml中的内容
  errors.required={0} is required.
  errors.minlength={0} can not be less than {1} characters.
  <formset>
   <form name=”loginForm”>
    <field property=”userName” depends=”required”>
     <arg0 key=”userName” />
    </field>
    <field property=”pwd” depends=”required,minlength”>
     <arg0 key=”pwd” />
     <arg1 key=”${var:minlength}” resource=”false”/>
     <var>
      <var-name>minlength</var-name>
      <var-value>6</var-value>
     </var>
    </field>
   </form>
  </formset>
  struts-config.xml中修改action的标签validate=true
    input=”/错误页面”