JSF reference implementation of SUN gives certain defaulting validation components which are leveraged so that user input validation could be implemented. Core library of JSF provides tags so that input could be validated. Few tags are given here which are used for validation of the input. f:validateDoubleRange: Component value is checked by this tag, within range. It is necessary for value to be convertiable to floating point or floating point type. f:validateLength:
This tag registers as well as adds the validator to that parent component which is nearest. Typically, all of the applications present would be requiring filling some information at the page. Therefore it is considered to be a better thing to get invalid info value or formatting so that to make it “user-friendly”. Hence faults could be found out and corrected. Built in rules of validation are provided by JSF. JSF also customized the rules of validation so that to make them according to the requirements.
JSF validators are used to support input validation and save lot of time of programmers in writing custom validation methods. JSF contains a large set of validator classes. Following are the some of built-in validators.
• DoubleRangeValidator: Any numeric type, between specified maximum and minimum values
• LongRangeValidator: Any numeric type convertible to long, between specified maximum and minimum values
• LengthValidator: Ensures that the length of a component's