Struts1.x Series Tutorials: built-in standard validation for validator validation framework

The predefined validation of the validator framework (the version number of struts is 1.2.9) is listed below.

Validator	Variable	Raising conditions
Required		field only spaces
Validwhen	Test	Test condition failed (see next section)
MinLength	MinLength	The number of characters in the field is less than minlength
MaxLength	MaxLength	The number of characters in the field is greater than maxlength
Mask	Mask	The field value does not match a regular expression that mask refers to
Byte, short, Integer, long, float, double		Field values cannot be converted to these data types
Date	Datepattern or Datepatternstrict	Character value values cannot be converted to date types in the specified format
Intrange, Floatrange, Doublerange	Min, max	field value is not in the specified range
CreditCard		Field value is not a credit card number
Email		Field value is not a valid email
Url	Allowallschemes, Allow2slashes, Nofragments, Schemes	field is not a URL

For more information about validator Framework standard validation, readers can access the following URL:

Http://struts.apache.org/1.2.9/userGuide/dev_validator.html

Here's an example of Validwhen validation.

Validwhen can verify the relationship between the current property and other properties, such as when validating a password, make sure that the password entered two times is identical and the authentication code is as follows:

<field property= "Password1" depends= "Validwhen" >
    <msg name= "Validwhen" key= "Error.password1.confirmation"/>
    <var>
        <var-name>test</var-name>
        <var-value>
            (password1!= null) and (*this* = = password)
        </var-value>
    </var>
</field>

You can also use Validwhen to validate nested and indexed properties, as shown in the following code:

<field property= "field1" depends= "Validwhen" >
    <msg name= "Validwhen" key= "Error.field.message"/>
    <var>
        <var-name>test</var-name>
        <var-value>
            (*this* = = Field2.name) and (*this*!= field3[1])
        </var-value>
    </var>
</field>

Where *this* represents the value of the current property.