按步就班使用struts验证框架

使用动态FormBean与struts验证框架

第一步，安装插件，在struts-config.xml中配置

<message-resources parameter="ApplicationResources" />

<plug-in className="org.apache.struts.validator.ValidatorPlugIn">
        <set-property property="pathnames" value="/WEB-INF/validator-rules.xml,/WEBINF/validation.xml" />
</plug-in>

validator-rules.xml是struts自带的，validation.xml须要自已新建

第二步，将validator-rules.xml中以下代码

#------------------------ERROR-----------------
errors.required={0} is required.
errors.minlength={0} can not be less than {1} characters.
errors.maxlength={0} can not be greater than {1} characters.
errors.invalid={0} is invalid.

errors.byte={0} must be a byte.
errors.short={0} must be a short.
errors.integer={0} must be an integer.
errors.long={0} must be a long.
errors.float={0} must be a float.
errors.double={0} must be a double.

errors.date={0} is not a date.
errors.range={0} is not in the range {1} through {2}.
errors.creditcard={0} is an invalid credit card number.
errors.email={0} is an invalid e-mail address.

拷贝到ApplicationResources.properties中，为了支持国际化ApplicationResources.properties同目录下新建ApplicationResources_zh_CN.properties需注意的是中文内容需通过native2ascii.exe进行转换。
命令使用格式：native2ascii 原文件 目标文件
我自已的常用做法是在JDK的ben目录下建一个.bat文件
内容：
cd %java_home%/bin/
native2ascii ApplicationResources_chinese.properties ApplicationResources_zh_CN.properties

如：ApplicationResources_chinese.properties中的文本：
errors.invalid={0} 无效.
errors.required={0} 不能为空.
转换后ApplicationResources_zh_CN.properties中的文本：
errors.required={0} \u4e0d\u80fd\u4e3a\u7a7a.
errors.invalid={0} \u65e0\u6548.

第三步，新建formBean与action

<!--使用动态的验证表单-->
<form-bean name="regForm"
        type="org.apache.struts.validator.DynaValidatorForm">
        <form-property name="username" type="java.lang.String" />
        <form-property name="password" type="java.lang.String" />
        <form-property name="password2" type="java.lang.String" />
</form-bean>
......
<!--需注意得是validate属性必须为true-->
<action attribute="regForm" name="regForm" parameter="method"
        path="/userReg" scope="request" input="/view/user/regedit.jsp"
        type="org.springframework.web.struts.DelegatingActionProxy"
        validate="true">
        <forward name="regFail" path="/view/user/regedit.jsp" redirect="false" />
        <forward name="regSuccess" path="/view/user/login.jsp" redirect="false" />
</action>

第四步，在validator.xml中定义验证规则
struts自带一些验证规则可供使用：
Byte、CreditCard、Date、Double、Email、Float、Integer、Long、Mask、MinLength、MaxLength、Range、Required、Short
通过field元素的depends属性指定依赖
当然struts也提供了自定义验证类的使用：
如验证密码一致性,编写以下类(引自struts中的例子)

package com.note.validator;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.validator.Field;
import org.apache.commons.validator.GenericValidator;
import org.apache.commons.validator.ValidatorAction;
import org.apache.commons.validator.ValidatorUtil;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.validator.Resources;

public class CustomValidator {
        public CustomValidator() {
                super();
        }

        /**
         * 功能:验证密码一致性（函数名必须以validate开头）
         * @param bean
         * @param va
         * @param field
         * @param errors
         * @param request
         * @return
         */
        public static boolean validateTwoFields(Object bean, ValidatorAction va,
                        Field field, ActionErrors errors, HttpServletRequest request) {
                String value = ValidatorUtil
                                .getValueAsString(bean, field.getProperty());
                String sProperty2 = field.getVarValue("secondProperty");
                String value2 = ValidatorUtil.getValueAsString(bean, sProperty2);
                if (!GenericValidator.isBlankOrNull(value)) {
                        try {
                                if (!value.equals(value2)) {
                                        errors.add(field.getKey(), Resources.getActionError(
                                                        request, va, field));
                                        return false;
                                }
                        } catch (Exception e) {
                                errors.add(field.getKey(), Resources.getActionError(request,
                                                va, field));
                                return false;
                        }
                }
                return true;
        }

}

validator.xml文件示例

<form-validation>
        <global>
                <!-- 自定义验证器 -->
                <validator name="twoFields"
                        classname="com.note.validator.CustomValidator"
                        method="validateTwoFields"
                        methodParams="java.lang.Object,
                       org.apache.commons.validator.ValidatorAction,
                       org.apache.commons.validator.Field,
                       org.apache.struts.action.ActionErrors,
                       javax.servlet.http.HttpServletRequest"
                        msg="errors.twofields" />
                <!-- 自定义验证器 -->
                <!-- 全局常量 -->
                        <constant>
                                <constant-name>string6_20</constant-name>
                                <!--正则表达式-->
                                <constant-value>^\w{6,20}$</constant-value>
                        </constant>
                <!-- 全局常量 -->
        </global>

        <formset>
                <!-- 注册表单验证 -->
                <form name="regForm">
                        <field property="username" depends="required,mask">
                                <!--resource为true时将去ApplicationResources中查找对应key的值-->
                                <arg0 key="lable.username" resource="true" />
                                <var>
                                        <var-name>mask</var-name>
                                        <var-value>${string6_20}</var-value>
                                </var>
                        </field>
                        <field property="password"
                                depends="required,mask,twoFields">
                                <arg0 key="lable.password" resource="true" />
                                <var>
                                        <var-name>mask</var-name>
                                        <var-value>${string6_20}</var-value>
                                </var>
                                <var>
                                        <var-name>secondProperty</var-name>
                                        <var-value>password2</var-value>
                                </var>
                        </field>
                </form>
        </formset>
</form-validation>

第五步，结合action一起使用

        /**
         * 功能:新用户注册
         * 
         * @param mapping
         * @param form
         * @param request
         * @param response
         * @return
         */
        public ActionForward regedit(ActionMapping mapping, ActionForm form,
                        HttpServletRequest request, HttpServletResponse response) {
                DynaActionForm regForm = (DynaActionForm) form;
                String username = (String) regForm.get("username");
                String password = (String) regForm.get("password");
                Users user = this.ius.getUserByName(username);
                ActionErrors errors = new ActionErrors();
                if (user == null) {
                        user = new Users();
                        user.setUsername(username);
                        user.setPassword(password);
                        user.setLevel(0);
                        user.setAddtime(new java.util.Date());
                        user.setLastime(new java.util.Date());
                        this.ius.addUser(user);
                } else {
                        errors.add("username", new ActionError("errors.username.exist"));
                        this.saveErrors(request, errors);
                        return mapping.findForward("regFail");
                }
                return mapping.findForward("regSuccess");
        }

到此为止,struts验证框架的使用基本完成。