窗口验证方法：
1.validate()方法
2.Struts2框架验证
1.窗口验证
1）ation配置
<action name="Logon" class="com.meetcomet.logon"> <result name="input">Login.jsp</result> <result name="success">/WEB-INF/pages/Hello.jsp</result> <result name="error">Error.jsp</result> </action>
一定要配置input，验证不通过会回到input页面
2）Logon.action
覆盖validate()方法
@Override public void validate() { // TODO Auto-generated method stub if (getUsername() == null || getUsername().trim().equals("")) { addFieldError("username", getText("login.user.required")); } if (getPassword() == null || getPassword().trim().equals("")){ addFieldError("password",getText("login.password.required")); }
3）Login.jsp页面
<%@page language="java"import="java.util.*"pageEncoding="GBK"%> <%@taglib prefix="s"uri="/struts-tags"%> <html> <body> <s:form action="Logon" method="post" > <s:textfield key="username"/><s:fielderror fieldName="username" /> <s:textfield key="password"/><s:fielderror fieldName="password"/> <s:submit value="确定"/> </s:form> </body></html>
如果用<s:form>标签，不用写<s:fielderror fieldName="username" />，会自动显示在上方。