Struts验证框架

actiong：

UserAction文件

public String login() throws Exception {System.out.println(user.getUserName());System.out.println(user.getPassWord());System.out.println("service-->"+service);if (service.isLogin(user)) {System.out.println("执行登陆impl成功");Map session = ActionContext.getContext().getSession();session.put("username", user.getUserName());return "success";}return "input";}

新建一个UserAction-validation.xml文件

<validators><field name="userName"><field-validator type="requiredstring"><param name="trim">true</param><message>name is required</message></field-validator></field></validators>

jsp页面

<s:fielderror>    <s:param>userName</s:param></s:fielderror>