Action類名-validation.xmlAction類名-映射名-validation.xml(映射名為 struts.xml 中 <action name="..."> 的值)調用 addFieldError(),頁面用 <s:fielderror/> 顯示。
<validators>
<field name="username">
<field-validator type="requiredstring">
<param name="trim">true</param>
<message>username should not be blank!</message>
</field-validator>
<field-validator type="stringlength">
<param name="minLength">6</param>
<param name="maxLength">10</param>
<message>username should be between ${minLength} and ${maxLength}</message>
</field-validator>
</field>
<!-- password, repassword, age, birthday, graduation 同理 -->
</validators>
| 驗證器名稱 | 適用類型/用途 |
|---|---|
| required / requiredstring | 非空 / 非空字符串 |
| int / long / short / double | 數值範圍 |
| date | 日期範圍 |
| expression / fieldexpression | OGNL 表達式驗證 |
| email / url | 郵箱 / URL 格式 |
| visitor | 級聯驗證嵌套對象 |
| conversion | 類型轉換錯誤 |
| stringlength | 字符串長度 |
| regex | 正則表達式 |
| conditionalvisitor | 條件級聯驗證 |
<field>)與「非字段驗證器」(<validator>),推薦前者${minLength} 等參數佔位符