org.apache.jasper.JasperException: Cannot find ActionMappings or ActionFormBeans

老是出现这个问题:  org.apache.jasper.JasperException: Cannot find ActionMappings or ActionFormBeans collection
  WEB-INF/lib/下有struts.jar
  WEB-INF/classes/下有dw.strust.example.EmployeeForm
  和dw.strust.example.ValidateEmployeeAction
  WEB-INF/下有struts-logic.tld,struts-bean.tld,struts-html.tld,struts-config.xml
  web.xml,app.tld
 
  我现在已经把表单只设置了一个字段了，就一个name
  EmployeeForm.java里面就一个name属性:
 
  package dw.strust.example;
  import org.apache.struts.action.ActionForm;
  public class EmployeeForm extends ActionForm{
  private String name = "";
 
  public String getName(){
  return name;
  }
 
  public void setName(String name){
  this.name = name;
  }
  public EmployeeForm() {
  }
  }
 
  ValidateEmployeeAction.java也只留下了name判断:
  package dw.strust.example;
  import org.apache.struts.action.*;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.servlet.ServletException;
  import java.io.IOException;
  import java.util.List;
 
  /**
  * <p>Title: </p>
  * <p>Description: </p>
  * <p>Copyright: Copyright (c) 2004</p>
  * <p>Company: </p>
  * @author not attributable
  * @version 1.0
  */
 
  public class ValidateEmployeeAction extends Action{
  public ValidateEmployeeAction() {
  }
 
  public ActionForward perform(ActionMapping mapping,
    ActionForm form,
    HttpServletRequest request,
    HttpServletResponse response)
    throws IOException,ServletException{
  ActionErrors errors = new ActionErrors();
  EmployeeForm empForm = (EmployeeForm)form;
 
  String name = empForm.getName();
  if(name.trim().equals("")){
  ActionError error = new ActionError("error.missing.name");
  errors.add(ActionErrors.GLOBAL_ERROR,error);
  System.out.println("sssss");
  }
  return mapping.findForward("success");