外部化/集中化JSF2中的验证属性

Question

This is an example of an input field in JSF having the validateLength validator.

<p:inputText id="priceModelName" size="30"
    value="#{createPriceModelBackingBean.priceModel.priceModelName}"
    required="true" label="#{labelResource.priceModelName}">
    <f:validateLength minimum="3" maximum="45" />
</p:inputText>

The priceModelName input field is repeated in another xhtml (create.xhtml and edit.xhtml), i would like to have the values for minimum and maximum externalized / centralized so that it is not repeated. Is there a good recommendation for such a use case?

I was thinking of probably using a properties file.

<f:validateLength minimum="#{validationResource.priceModel.minimum}" maximum="#{validationResource.priceModel.minimum}" />

Answer 1

Apart from the way you found out yourself, another ways are:

1. Extend the JSF LengthValidator and set the defaults in the constructor.

    @FacesValidator("priceModelNameLengthValidator") public class PriceModelNameLengthValidator extends LengthValidator { public PriceModelNameLengthValidator() { setMinimum(3); setMaximum(45); } } 

   (make those magic numbers if necessary constants or configuration settings)

   and reuse it

    <f:validator validatorId="priceModelNameLengthValidator" /> 

   ---

2. Use JSR 303 bean validation.

    @Size(min=3, max=45) private String priceModelName;