Registering a Custom Validator - The J2EE 1.4 Tutorial

Registering a Custom Validator

If the application developer provides an implementation of the Validator interface to perform the validation, you must register this custom validator in the application configuration resource file by using the validator XML element:

<validator>
  ...
  <validator-id>FormatValidator</validator-id>
  <validator-class>
    validators.FormatValidator
  </validator-class>
  <attribute>
    ...
    <attribute-name>formatPatterns</attribute-name>
    <attribute-class>java.lang.String</attribute-class>
  </attribute>
</validator> 

The validator-id and validator-class elements are required subelements. The validator-id element represents the identifier under which the Validator class should be registered. This ID is used by the tag class corresponding to the custom validator tag.

The validator-class element represents the fully qualified class name of the Validator class.

The attribute element identifies an attribute associated with the Validator implementation. It has required attribute-name and attribute-class subelements. The attribute-name element refers to the name of the attribute as it appears in the validator tag. The attribute-class element identifies the Java type of the value associated with the attribute.

Creating a Custom Validator explains how to implement the Validator interface.

Using a Custom Validator explains how to reference the validator from the page.

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