SelectOneMenu always shows first item not the selected - Primefaces - jsf

Question

Some help would be appreciated on this issue.
I have several JSF Pages, but one of them is a Subcategory where there is a SelectOneMenu for choosing the Category, but when I try to edit the subcategory, this SelectOneMenu always shows the first value and is not getting preselected.
How could I solve this. I have read a lot of SO posts and eventhougn I have implemented a couple of advice I have not achieved it. for example, a #BalusC's one:
primefaces selectOneMenu doesn't working when it should
Here is the View
<h:outputText value="Subcategory ID : #{subcategoryController.subcategory.subcategoryId}"/>
<p:selectOneMenu id="cboCategoryDialog" converter="subcategoryConverter"
value="#{subcategoryController.category.categoryId}"
style="width: 100%"
<f:selectItems value="#{subcategoryController.categoryList}"
var="subcat"
itemLabel="#{subcat.categoryName}"
itemValue="#{subcat.categoryId}"/>
</p:selectOneMenu>**
This is the Subcategory Entity:
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "subcategory_id")
private Integer subcategoryId;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 45)
#Column(name = "subcategory_name")
private String subcategoryName;
#JoinColumn(name = "category_id", referencedColumnName = "category_id")
#OneToOne(optional = false;
private Category categoryId;
//Getters and Setters Methods
#Override
public int hashCode() {
return (subcategoryId != null)
? (this.getClass().hashCode() + subcategoryId.hashCode())
: super.hashCode();
}
#Override
public boolean equals(Object obj) {
return (obj instanceof Subcategory) && (subcategoryId != null)
? subcategoryId.equals(((Subcategory) obj).subcategoryId)
: (obj == this);
}
SubcategoryConverter
#RequestScoped
#FacesConverter("subcategoryConverter")
public class SubcategoryConverter implements Converter {
#EJB
private SubcategoryFacadeLocal EJBsubcategory;
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (!(value instanceof Subcategory) || ((Subcategory) value).getSubcategoryId() == null) {
return null;
}
return String.valueOf(((Subcategory) value).getSubcategoryId());
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || !value.matches("\\d+")) {
return null;
}
Subcategory subcategory = EJBsubcategory.find(Integer.valueOf(value));
if (subcategory == null) {
throw new ConverterException(new FacesMessage("Unknown operation ID: " + value));
}
return subcategory;
}
}
Below image shows the Dialog when I try to edit any item, it always shows computer because its the first itm.
See the image showing the issue
I have been reading some related useful questions about this, but I have not been able to fix it.
Thanks in advance,

Answer 1

After reviewing the code, I realized that I was using the wrong entity in the JSF.:
For example:
In the question, I posted: subcategoryController.category.categoryId to save Category object in a subcategory object.
As follow:
<p:selectOneMenu id="cboCategoryDialog" converter="subcategoryConverter"
value="#{subcategoryController.category.categoryId}"
But, the correct approach is the following:
<p:selectOneMenu id="cboCategoryDialog" converter="omnifaces.SelectItemsConverter"
value="#{subcategoryController.subcategory.categoryId}"
Now, this component is "pointing" to the correct object.
Another issue that I was facing is:
As I have nested entities, example: Entity.entity.entity they should be inicialized in every level, before using it.
Some posts that really, really, really helped me on this:
On solving the nested entities issues (PropertyNotFoundException).
Identifying and solving javax.el.PropertyNotFoundException: Target Unreachable
On using normal and OmniFaces Converter on SelectOneMenu:
http://balusc.omnifaces.org/2007/09/objects-in-hselectonemenu.html

Answer 2

Be sure that your entity hashCode() and equals() methods are implemented and doesn't try to access nullable fields. That worked for me!