解决不了了

import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForm;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;import javax.servlet.ServletContext;
import javax.sql.DataSource;
import javax.servlet.http.*;public class LoginAction
    extends Action {
  public ActionForward execute(ActionMapping actionMapping,
                               ActionForm actionForm,
                               HttpServletRequest servletRequest,
                               HttpServletResponse servletResponse) {
    UserActionForm userActionForm = (UserActionForm) actionForm;
 
    String name = userActionForm.getName();
    String psw  = userActionForm.getPsw();
    
    ServletContext context = servlet.getServletContext();
    DataSource dataSource = (DataSource)context.getAttribute("datasource");
    
    DBUser dbuser = new DBUser(dataSource);
    HttpSession session = servletRequest.getSession();
    
    if(!(dbuser.checkUser(name,psw))){
      ActionMessages errors = new ActionMessages();
      errors.add(ActionMessages.GLOBAL_MESSAGE,new ActionMessage("label.deny"));
      
      if(!errors.isEmpty()){
        saveErrors(servletRequest,errors);========== 这个方法 到底 从那来的
        
      }
      return actionMapping.findForward("failed");
    }
    
    return actionMapping.findForward("successed");
  }
}