//I added this into faces-config.xml
    <validator>
        <validator-id>ValidatorController</validator-id>
        <validator-class>com.DX_57.HM_57.FormValidator</validator-class>
    </validator>

//This is the input field

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

//Validator code

import javax.enterprise.context.SessionScoped;
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.validator.Validator;
import javax.faces.validator.ValidatorException;
import javax.inject.Named;

@Named("ValidatorController")
@SessionScoped
public class FormValidator {

    public FormValidator() {
    }

    public void validateMessage(FacesContext context, UIComponent component, Object value) throws ValidatorException {
        throw new UnsupportedOperationException("Not supported yet.");
    }



}