如何使用CDI创建验证器

Question

I want to implement custom validator in which I can use CDI and datasource. I tested this code:

<h:panelGroup>Session ID</h:panelGroup>
<h:panelGroup>
    <h:inputText id="sessionid" value="#{DatabaseController.formMap['sessionid']}" >
        <f:validateLength minimum="0" maximum="15"/>
        <f:validator validatorId="ValidatorController" >
        </f:validator>
        <f:ajax event="blur" render="sessionidMessage" />                                          
    </h:inputText>
    <h:message id="sessionidMessage" for="sessionid" />
</h:panelGroup>

This is the validator:

    @FacesValidator("ValidatorController")

    public class FormValidator implements Validator {

        public FormValidator() {
        }

        @Override
        public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
            if (value.equals("test")) {
                throw new ValidatorException(new FacesMessage(FacesMessage.SEVERITY_ERROR,
                        "  Session ID is already in use, please choose another.", null));
            }
        }
}

This code works fine. I also tried to implement this code in order to use CDI into the validator:

<h:panelGroup>Session ID</h:panelGroup>
<h:panelGroup>
    <h:inputText id="sessionid" value="#{DatabaseController.formMap['sessionid']}" >
        <f:validateLength minimum="0" maximum="15"/>
        <f:validator binding="#{ValidatorController}" >
            <f:attribute name="type" value="sessionid" />
        </f:validator>
        <f:ajax event="blur" render="sessionidMessage" />                                          
    </h:inputText>
    <h:message id="sessionidMessage" for="sessionid" />
</h:panelGroup>

This is the validator:

@Named("ValidatorController")

public class FormValidator implements Validator {

    public FormValidator() {
    }

    @Override
    public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
        if (value.equals("test")) {
            throw new ValidatorException(new FacesMessage(FacesMessage.SEVERITY_ERROR,
                    "  Session ID is already in use, please choose another.", null));
        }
    }

}

For some reason the second example is not working.

Answer 1

You should be more specific, what fails? It does not compile? It does not run? What is the exception, etc. And also it is not clear what are you trying to achieve in 2nd case.

In general, you can not pass the attribute to the f:validator by nesting f:attribute insside. Make your code look like this:

<f:validator binding="#{ValidatorController}" (session id in your case) />
<f:attribute name="type" value="sessionid" />

Later on you can search for the component parameter inside component parameter Map:

context.getExternalContext().getRequestParameterMap();