[標(biāo)題]:[原]Struts2校驗(yàn)框架
[時(shí)間]:2009-7-27
[摘要]:校驗(yàn)框架配置、客戶端校驗(yàn)
[關(guān)鍵字]:浪曦視頻,Struts2應(yīng)用開發(fā)系列,WebWork,Apache,validation
[環(huán)境]:struts-2.1.6、JDK6、MyEclipse7、Tomcat6
[作者]:Winty (wintys@gmail.com) http://www.aygfsteel.com/wintys

[正文]:
    Struts校驗(yàn)框架提供了一種不用編寫代碼,只需修改配置文件即可對(duì)輸入進(jìn)行校驗(yàn)的功能。代碼方式校驗(yàn),即重寫validate()方法。實(shí)際應(yīng)用中,validate()與校驗(yàn)框架一般只選其一

1、校驗(yàn)框架配置
    在RegisterAction.java相同目錄新建校驗(yàn)框架配置文件RegisterAction-validation.xml。RegisterAction-validation.xml的DTD可以復(fù)制struts自帶的示例struts2-mailreader-2.1.6中的DTD:
<!DOCTYPE validators PUBLIC
          "-//OpenSymphony Group//XWork Validator 1.0.2//EN"
          "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

xwork-validator-1.0.2.dtd:
<?xml version="1.0" encoding="UTF-8"?>

<!--
  XWork Validators DTD.
  Used the following DOCTYPE.
 
  <!DOCTYPE validators PUBLIC
          "-//OpenSymphony Group//XWork Validator 1.0.2//EN"
          "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
-->


<!ELEMENT validators (field|validator)+>

<!ELEMENT field (field-validator+)>
<!ATTLIST field
    name CDATA #REQUIRED
>

<!ELEMENT field-validator (param*, message)>
<!ATTLIST field-validator
    type CDATA #REQUIRED
    short-circuit (true|false) "false"
>

<!ELEMENT validator (param*, message)>
<!ATTLIST validator
    type CDATA #REQUIRED
    short-circuit (true|false) "false"
>

<!ELEMENT param (#PCDATA)>
<!ATTLIST param
    name CDATA #REQUIRED
>

<!ELEMENT message (#PCDATA)>
<!ATTLIST message
    key CDATA #IMPLIED
>


RegisterAction-validation.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC
          "-//OpenSymphony Group//XWork Validator 1.0.2//EN"
          "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
 
 <validators>
 <!--  
     與field等價(jià)的validator
     <validator type="requiredstring">
         <param name="fieldName">name</param>
         <param name="trim">true</param>
         <message>name required</message>
     </validator>
     <validator type="stringlength">
         <param name="fieldName">name</param>
             <param name="trim">true</param>
             <param name="minLength">6</param>
             <param name="maxLength">10</param>
             <message>name length range : ${minLength} ~ ${maxLength}</message>
     </validator>
 -->    
     <field name="name">
         <field-validator type="requiredstring" >
             <param name="trim">true</param>
             <message>name required</message>
         </field-validator>
         <field-validator type="stringlength">
             <param name="trim">true</param>
             <param name="minLength">6</param>
             <param name="maxLength">10</param>
             <message>name length range : ${minLength} ~ ${maxLength}</message>
         </field-validator>
     </field>
     
     <field name="age">
         <field-validator type="conversion" short-circuit="true">
             <message>the field age conversion error</message>
         </field-validator>
         <field-validator type="int">
             <param name="min">1</param>
             <param name="max">150</param>
             <message>age range: ${min} ~ ${max}</message>
         </field-validator>
     </field>
     
     <field name="birthday">
         <field-validator type="required">
             <message>birthday required</message>
         </field-validator>
         <field-validator type="date">
             <param name="min">2009-01-01</param>
             <param name="max">2009-12-31</param>
             <message>birthday range: ${min} ~ ${max}</message>
         </field-validator>
     </field>
     
     <field name="email">
         <field-validator type="email">
             <message>invalid email address</message>
         </field-validator>
     </field>
 </validators>

說明:
a.校驗(yàn)框架有兩種校驗(yàn)方式:field和validator。
field校驗(yàn):先指定需要校驗(yàn)的屬性,再指定校驗(yàn)方式。validator校驗(yàn):先指定校驗(yàn)方式,再指定需要校驗(yàn)的屬性。兩種方式是等價(jià)的。

field校驗(yàn):
<field name="name">
    <field-validator type="requiredstring" >
        <param name="trim">true</param>
        <message>name required</message>
    </field-validator>
    <field-validator type="stringlength">
        <param name="trim">true</param>
        <param name="minLength">6</param>
        <param name="maxLength">10</param>
        <message>name length range : ${minLength} ~ ${maxLength}</message>
    </field-validator>
</field>

validator校驗(yàn):
<validator type="requiredstring">
    <param name="fieldName">name</param>
    <param name="trim">true</param>
    <message>name required</message>
</validator>
<validator type="stringlength">
    <param name="fieldName">name</param>
    <param name="trim">true</param>
    <param name="minLength">6</param>
    <param name="maxLength">10</param>
    <message>name length range : ${minLength} ~ ${maxLength}</message>
</validator>

b.<field-validator type="requiredstring" >中的type及其對(duì)應(yīng)的xwork類可以在xwork-2.1.2.jar/com.opensymphony.xwork2.validator.validators/default.xml中查找到。
default.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE validators PUBLIC
        "-//OpenSymphony Group//XWork Validator Config 1.0//EN"
        "http://www.opensymphony.com/xwork/xwork-validator-config-1.0.dtd">

<!-- START SNIPPET: validators-default -->
<validators>
    <validator name="required" class="com.opensymphony.xwork2.validator.validators.RequiredFieldValidator"/>
    <validator name="requiredstring" class="com.opensymphony.xwork2.validator.validators.RequiredStringValidator"/>
    <validator name="int" class="com.opensymphony.xwork2.validator.validators.IntRangeFieldValidator"/>
    <validator name="long" class="com.opensymphony.xwork2.validator.validators.LongRangeFieldValidator"/>
    <validator name="short" class="com.opensymphony.xwork2.validator.validators.ShortRangeFieldValidator"/>
    <validator name="double" class="com.opensymphony.xwork2.validator.validators.DoubleRangeFieldValidator"/>
    <validator name="date" class="com.opensymphony.xwork2.validator.validators.DateRangeFieldValidator"/>
    <validator name="expression" class="com.opensymphony.xwork2.validator.validators.ExpressionValidator"/>
    <validator name="fieldexpression" class="com.opensymphony.xwork2.validator.validators.FieldExpressionValidator"/>
    <validator name="email" class="com.opensymphony.xwork2.validator.validators.EmailValidator"/>
    <validator name="url" class="com.opensymphony.xwork2.validator.validators.URLValidator"/>
    <validator name="visitor" class="com.opensymphony.xwork2.validator.validators.VisitorFieldValidator"/>
    <validator name="conversion" class="com.opensymphony.xwork2.validator.validators.ConversionErrorFieldValidator"/>
    <validator name="stringlength" class="com.opensymphony.xwork2.validator.validators.StringLengthFieldValidator"/>
    <validator name="regex" class="com.opensymphony.xwork2.validator.validators.RegexFieldValidator"/>
    <validator name="conditionalvisitor" class="com.opensymphony.xwork2.validator.validators.ConditionalVisitorFieldValidator"/>
</validators>
<!--  END SNIPPET: validators-default -->

c. 對(duì)于校驗(yàn)<field-validator type="requiredstring" >:String用requiredstring,其它類型用required。
d. 驗(yàn)證錯(cuò)誤將默認(rèn)產(chǎn)生FieldError。
e. short-circuit="true" : 一個(gè)校驗(yàn)失敗,是否是繼續(xù)執(zhí)行后續(xù)校驗(yàn)。
f. 對(duì)于相同屬性的FieldError,validate()方法中的驗(yàn)證和RegisterAction-validation.xml中的驗(yàn)證都會(huì)執(zhí)行,并且FieldError都會(huì)顯示。
執(zhí)行順序: RegisterAction-validation.xml => validate()。


2、特定于業(yè)務(wù)邏輯的局部校驗(yàn):
對(duì)于struts.xml中<action>的method="register"指定的業(yè)務(wù)方法register(),使用校驗(yàn)RegisterAction-register-validation.xml(與RegisterAction.java在同一目錄下)。同時(shí),RegisterAction-validation.xml會(huì)被執(zhí)行。執(zhí)行順序:  RegisterAction-validation.xml => RegisterAction-register-validation.xml

3、Struts2客戶端校驗(yàn)
    設(shè)置struts標(biāo)簽<s:form>中validate="true"。這樣就會(huì)根據(jù)RegisterAction-validation.xml生成頁面Javascript,在客戶端執(zhí)行校驗(yàn)。
 
 注意:
 a.struts標(biāo)簽不能使用simple主題。
 b.Struts2客戶端校驗(yàn)功能較弱,一般不用。

4、FieldError和ActionError的實(shí)現(xiàn)
a.真正存放field級(jí)別錯(cuò)誤信息的對(duì)象是LinkedHashMap。
b.該LinkedHashMap的key是String類型的,value是ArrayList類型,所以同一個(gè)key可以對(duì)應(yīng)多個(gè)錯(cuò)誤消息。
c.對(duì)于Action級(jí)別的錯(cuò)誤信息,實(shí)際上是放置在ArrayList中的。
    
[參考資料]:
    《浪曦視頻之Struts2應(yīng)用開發(fā)系列》