表单验证-dwr,Validator,Struts2

    基于AJAX的表单验证需要先安装DWR，在http://getahead.ltd.uk/dwr/download上下载DWR 2.0 RC 2，将dwr.jar拷贝到WEB-INF/lib目录下

1．修改web.xml，另入DWR支持：

xml 代码

<servlet>
        <servlet-name>dwr<!---->servlet-name>
        <servlet-class>
            org.directwebremoting.servlet.DwrServlet
        <!---->servlet-class>
        <init-param>
            <param-name>debug<!---->param-name>
            <param-value>true<!---->param-value>
        <!---->init-param>
 <!---->servlet>
 <servlet-mapping>
     <servlet-name>dwr<!---->servlet-name>
     <url-pattern>/dwr/*<!---->url-pattern>
<!---->servlet-mapping>

2．在WEB-INF目录下新建dwr.xml文件：

xml 代码

xml version="1.0" encoding="UTF-8"?>

"http://getahead.ltd.uk/dwr/dwr20.dtd">
<dwr>
    <allow>
        <create javascript="validator" creator="new">
            <param name="class"
                value="org.apache.struts2.validators.DWRValidator" />
        <!---->create>
        <convert converter="bean"
            match="com.opensymphony.xwork2.ValidationAwareSupport" />
    <!---->allow>

    <signatures>
        <!---->
    <!---->signatures>
<!---->dwr>

3．在login.jsp中添加AJAX验证支持，修改后的login.jsp内容如下：

java 代码

 1. <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
 2. <%@taglib prefix="s" uri="/struts-tags"%>
 3.
 4.
 5.         "ajax" />
 6.
 7.
 8.
 9.         "login" method="post" theme="ajax">
10.             "用户名" name="username" />
11.             "密码" name="password" />
12.             "登录" />
13.
14.
15.

注意上面的<s:head theme="ajax" />，它为页面使用AJAX验证准备相应的Scripts代码。<o:p></o:p>

4.配置validation.xml:

xml 代码

xml version="1.0" encoding="UTF-8"?>

"-//OpenSymphony Group//XWork Validator 1.0.2//EN"
"http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
<validators>
    <field name="username">
        <field-validator type="requiredstring">
            <message>请输入用户名<!---->message>
        <!---->field-validator>
    <!---->field>

    <field name="password">
        <field-validator type="requiredstring">
            <message>请输入密码<!---->message>
        <!---->field-validator>
        <field-validator type="stringlength">
            <param name="minLength">6<!---->param>
            <param name="maxLength">10<!---->param>
            <message>密码长度只能在 ${minLength} 和 ${maxLength} 之间.<!---->message>
        <!---->field-validator>
    <!---->field>
<!---->validators>

这样就为JSP页面提供了基于AJAX的验证。