Struts2学习笔记4-数据输入校验(使用框架)

struts2还支持XML配置文件来验证参数的是否正确

在与Action文件同目录的地方建一个和Action文件同名的XML文件
如RegisterAction类的XML配置文件是RegisterAction-validation.xml

内容如下，开头的DTD可以从Struts2下载的文件的例子里面找

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
<validators>
	<!-- 表示Action里面的username字段 -->
	<field name="username">
		<!-- 一个验证方法,可以去com.opensymphony.xwork2.validator.validators里面-->
		<!--的default.xml里面找到type所以有的类型,每个内型里对应着相应的类,类里面有相应的参数和对参数的get,set方法-->
		<!--,参数就是param里面的name值,好像get,set方法就是验证的方法,这个没有看到源码-->
		<field-validator type="requiredstring">
			<param name="trim">true</param>
			<!-- 错误输出信息 -->
			<message>username is null</message>
		</field-validator>
		
		<field-validator type="stringlength">
			<param name="minLength">6</param>
			<param name="maxLength">15</param>
			<message>username must between ${minLength} and ${maxLength}</message>
		</field-validator>
	</field>
	
	<field name="password">
		<field-validator type="requiredstring">
			<!-- <param name="trim">true</param>可以不写 -->
			<message>password is null</message>
		</field-validator>
		
		<field-validator type="stringlength">
			<param name="minLength">6</param>
			<param name="maxLength">15</param>
			<message>password must between ${minLength} and ${maxLength}</message>
		</field-validator>
	</field>
	
	<field name="repassword">
		<field-validator type="requiredstring">
			<!-- <param name="trim">true</param>可以不写 -->
			<message>password is null</message>
		</field-validator>
		
		<field-validator type="stringlength">
			<param name="minLength">6</param>
			<param name="maxLength">15</param>
			<message>password must between ${minLength} and ${maxLength}</message>
		</field-validator>
	</field>
	
	<field name="age">
		<field-validator type="required">
			<message>age is null</message>
		</field-validator>
		<field-validator type="int">
			<param name="min">1</param>
			<param name="max">150</param>
			<message>age must between ${min} and ${max}</message>
		</field-validator>
	</field>
	
	<field name="birthday">
		<field-validator type="required">
			<message>birthday is null</message>
		</field-validator>
		
		<field-validator type="date">
			<param name="max">2004-12-31</param>
			<param name="min">2000-01-01</param>
			<message>birthday must between ${min} and ${max}</message>
		</field-validator>
	</field>
	
	<field name="graduation">
		<field-validator type="required">
			<message>graduation is null</message>
		</field-validator>
		<field-validator type="date">
			<param name="min">2005-01-01</param>
			<param name="max">2009-12-31</param>
			<message>graduation must between ${min} and ${max}</message>
		</field-validator>
	</field>
</validators>

这个里面验证的错误都是放到fielderror里面的，不是放到actionerror里面的
所以JSP页面使用<s:actionerror/>是不会显示的
要用<s:fielderror></s:fielderror>才会显示

当然如果你的Action extends ActionSupport 并重写了
validate*()方法，同时执行里面的代码，所以一般最好用一种就行了，不然会验证两次。