1.       创建自定义验证文件*.xml，放在web-info目录下

2.       在struts-config.xml配置文件中安装验证框架插件

1. <!-- 安装资源文件 --> 
2.   <message-resources parameter="xiao.zhang.struts.ApplicationResources" /> 
3.  
4.   <!-- 安装插件 --> 
5.   <plug-in className="org.apache.struts.validator.ValidatorPlugIn"> 
6.  
7.   <!-- 这里的pathnames是固定的，pathnames是ValidatorPlugIn类的一个属性字段 --> 
8.  
9.   <set-property 
10.  
11. property="pathnames" value="/WEB-INF/validator-rules.xml,/WEB-INF/loginForm_validator.xml"/> 
12.  
13.   </plug-in> 

3.       自定义验证文件中：

1. <?xml version="1.0" encoding="UTF-8"?> 
2.  
3. <!DOCTYPE form-validation PUBLIC "-//Apache Software Foundation//DTD Commons Validator Rules Configuration 1.0//EN" "validator_1_0.dtd" > 
4.  
5. <form-validation> 
6.        <formset> 
7.               <!--  name用来描述是使用Form验证或Action验证 
8.                      Form验证填写表单名 
9.                      Action验证填写Action的Path 
10. --> 
11.               <form name="loginForm"> 
12.  
13.                      <field property="userName" depends="required"> 
14.  
15.                             <arg0 key="userName" resource="true"></arg0> 
16.  
17.                      </field> 
18.                      <field property="passWord" depends="required,minlength,maxlength"> 
19.  
20.               <!--  resource为true使用资源文件信息 
21.                       resource为false不使用资源文件信息，使用<var>定义信息键值对</var> 
22.  - - >  
23.                             <arg0 key="passWord" resource="true"></arg0> 
24.  
25.                             <arg1 key="${var:minlength}" resource="false"></arg1> 
26.  
27.                             <arg2 key="${var:maxlength}" resource="false"></arg2> 
28.  
29.                             <var> 
30.                                    <var-name>minlength</var-name> 
31.                                    <var-value>6</var-value> 
32.                             </var> 
33.                             <var> 
34.                                    <var-name>maxlength</var-name> 
35.                                    <var-value>8</var-value> 
36.                             </var> 
37.                      </field> 
38.               </form> 
39.        </formset> 
40. </form-validation>