Struts 2 - XML Based Validators

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Following is the list of various types of field level and non-field level validation available in Struts2 −

date validator

<field name = "birthday">
   <field-validator type = "date">
      <param name = "min">01/01/1990</param>
      <param name = "max">01/01/2000</param>
      <message>
         Birthday must be within ${min} and ${max}
      </message>
   </field-validator>
</field>

double validator

<field name = "percentage">
   <field-validator type = "double">
      <param name = "minExclusive">0.123</param>
      <param name = "maxExclusive">99.98</param>
      <message>
         Percentage needs to be between ${minExclusive}
         ${maxExclusive} (exclusive)
      </message>
   </field-validator>
</field>

email validator

<field name = "myEmail">
   <field-validator type = "email">
      <message>
         Must provide a valid email
      </message>
   </field-validator>
</field>

expression validator

A Non-Field Level validator that validates based on regular expression supplied.

<field-validator type = "expression">
   <param name = "expression">....</param>
   <message>
      Failed to meet Ognl Expression  .... 
   </message>
</field-validator>

int validator

<field name = "age">
   <field-validator type = "int">
      <param name = "min">5</param>
      <param name = "max">50</param>
      <message>
         Age needs to be between ${min} and ${max}
      </message>
   </field-validator>
</field>

regex validator

<field name = "myStrangePostcode">
   <field-validator type = "regex">
      <param name = "fieldName">myStrangePostcode</param>
         <param name = "expression">
         <![CDATA[([aAbBcCdD][123][eEfFgG][456])]]>
      </param>
   </field-validator>
</field>

required validator

<field name = "username">
   <field-validator type = "required">
      <message>
         username must not be null
      </message>
   </field-validator>
</field>

requiredstring validator

<field name = "username">
   <field-validator type = "requiredstring">
     <param name = "trim">true</param>
     <message>
         username must not be null
      </message>
   </field-validator>
</field>

stringlength validator

<field name = "username">
   <field-validator type = "stringlength">
      <param name = "minLength">10</param>
      <param name = "maxLength">10</param>
      <param name = "trim">true</param>
      <message>
         Your username needs to be 10 characters long
      </message>
   </field-validator>
</field>

url validator

<field-validator type = "url">
   <param name = "fieldName">myHomePageURL</param>
   <message>
     Invalid homepage url
   </message>
</field-validator>