struts2添加自己的校验器

1、写一个校验类
命名规范为校验名+Validator，该类必须继承FieldValidatorSupport，覆盖validate方法

package cn.jieou.struts.validate;

import com.opensymphony.xwork2.validator.ValidationException;
import com.opensymphony.xwork2.validator.validators.FieldValidatorSupport;

public class AgeValidator extends FieldValidatorSupport{

    /**
     * object指的是action对象
     */
    @Override
    public void validate(Object object) throws ValidationException {
        String fieldName = this.getFieldName();
        Object fieldValue = this.getFieldValue(fieldName, object);
        if (fieldValue instanceof Integer) {
            Integer age = (Integer) fieldValue;
            //校验如果年龄小于0的话返回错误信息
            if (age < 0) {
                this.addFieldError(fieldName, object);
            }
        }
    }
}

2、创建validators.xml配置文件，把上面的校验类交给struts2管理

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC
        "-//Apache Struts//XWork Validator Definition 1.0//EN"
        "http://struts.apache.org/dtds/xwork-validator-definition-1.0.dtd">
<validators>
    <validator name="age" class="cn.jieou.struts.validate.AgeValidator"></validator>
</validators>

3、在指定的校验配置文件中添加校验配置
Validatection-validation.xml这里我用上一篇写好的校验配置文件

<!-- 年龄校验 -->
    <field name="age">
        <field-validator type="age">
            <message><![CDATA[年龄必能小于0]]></message>
        </field-validator>
    </field>