At least one/group of multiple fields required in JSF - validation

Question

I'm trying to do a search function of which I have multiple fields and need at least one of them required, or a group of them.
The only answer I found on StackOverflow is this one: How to validate if at least one of multiple input fields is entered?
And there are 2 solutions there: One uses Omnifaces (which I can't use due to project requirements), and the other is not elegant, because it grows a lot when the number of fields is big.
I have these fields for example:
<p:selectOneMenu value="#{backingBean.type}"id="type">
<f:selectItem itemLabel="#{constantsController.SELECT_TYPE_HEADER}"
itemDisabled="true" />
<f:selectItems
value="#{constantsController.getTypes().entrySet()}"
var="entry" itemValue="#{entry.key}" itemLabel="#{entry.value}" />
</p:selectOneMenu>
<p:inputText id="number" value="#{backingBean.number}"/>
<p:inputText id="year" value="#{backingBean.year}"/>
<p:inputText id="number2" value="#{backingBean.number2 }"/>
<p:selectOneMenu value="#{backingBean.state}"
id="state" filter="true" filterMatchMode="startsWith">
<f:selectItem itemLabel="Choose its state" disabled="true" />
<f:selectItems value="#{constantsController.getStates().entrySet()}"
var="entry" itemValue="#{entry.key}" itemLabel="#{entry.value}" />
</p:selectOneMenu>
<p:selectOneMenu id="entity"
value="#{backingBean.entity }">
<f:selectItem itemLabel="Select entity"
itemDisabled="true" />
<f:selectItem itemLabel="Entity1" itemValue="1"></f:selectItem>
<f:selectItem itemLabel="Entity2" itemValue="2"></f:selectItem>
</p:selectOneMenu>
<p:selectOneMenu id="documentType"
value="#{backingBean.documentType}">
<f:selectItems
value="#{constantsController.getDocumentTypes().entrySet()}"
var="entry" itemValue="#{entry.key}" itemLabel="#{entry.value}" />
</p:selectOneMenu>
<p:inputText id="documentNumber" value="#{backingBean.documentNumber}"/>
So as you can see, I have multiple fields. And the requirements dictate that I need one of the following required (I'll write the id's):
1- type + number + year
2- number2 + state
3- entity
4- documentType + documentNumber
So I when I click the commandButton, I need this to check if one of these groups (1, 2, 3 or 4) is filled.
Also, the groups in itself need to be required, i.e. let's say I already filled 'entity', and I also filled the 'year', it cannot let me advance since year needs to be accompanied by 'type' and 'number'.

Answer 1

I solved it by associating a boolean in the backing bean to each of the fields/group of fields. It's not an elegant solution, but I wasn't finding any other solution.
So what I did was define by group of fields in the backing bean a boolean initialized with true value:
private boolean typeNumberYear = true;
private boolean number2State = true;
private boolean entityRequired = true;
private boolean documentTypeDocumentName = true;
private boolean masterRequired = true;
then to validate them:
public void checkRequiredFields(){
if(!type.equals("") && number != 0 && year != 0)
typeNumberYear = false;
if(number2 != 0 && !state.equals(""))
number2State = false;
if(!entity.equals(""))
entityRequired= false;
if(!documentType.equals("") && documentNumber != 0)
documentTypeDocumentName = false;
if(!typeNumberYear || !number2State || !entityRequired || !documentTypeName)
masterRequired = false;
}
Since all this is in the backing bean, I can just put this function on the actionListener of the command button, while the action function is still in the controller.
<p:commandButton value="Search" icon="ui-icon-search"
actionListener="#{backingBean.checkRequiredFields}"
action="#{controller.searchButtonClicked}"/>
Now in the required parameter I just associated the respective boolean and the masterRequired on all of them. E.g. in the type, number and year inputs, I put the required as follows:
required = "backingBean.typeNumberYear and backingBean.masterRequired"
The only downside to this solution, is that in the interface, there will be appearing an asterisk on all the fields that are indicated above, but if you just input the entity for example, it will search as it is supposed to, and then it will update and remove the asterisks.