JSF greater than zero validator

jsf, jsf-2

Solution

Just create a custom validator, i.e. a class implementing `javax.faces.validator.Validator`, and annotate it with `@FacesValidator("positiveNumberValidator")`.

Implement the `validate()` method like this:

@Override
public void validate(FacesContext context, UIComponent component,
        Object value) throws ValidatorException {

    try {
        if (new BigDecimal(value.toString()).signum() < 1) {
            FacesMessage msg = new FacesMessage("Validation failed.", 
                    "Number must be strictly positive");
            msg.setSeverity(FacesMessage.SEVERITY_ERROR);
            throw new ValidatorException(msg); 
        } 
    } catch (NumberFormatException ex) {
        FacesMessage msg = new FacesMessage("Validation failed.", "Not a number");
        msg.setSeverity(FacesMessage.SEVERITY_ERROR);
        throw new ValidatorException(msg); 
    }
}

And use it in the facelets page like this:

<h:inputText id="percentage" value="#{lab.percentage}">
    <f:validator validatorId="positiveNumberValidator" />
</h:inputText>

Useful link: http://www.mkyong.com/jsf2/custom-validator-in-jsf-2-0/

Problem

How do you create a validator in JSF that validates the input text if it is greater than zero? ``` <h:inputText id="percentage" value="#{lab.percentage}"> <f:validateDoubleRange minimum="0.000000001"/> </h:inputText> ``` I have the code above but I am not sure if this is optimal. Although it works but if another number lesser than this is needed then I need to change the jsf file again. The use case is that anything that is greater than zero is okay but not negative number. Any thoughts?

Original source

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