问SelectOneMenu始终显示第一个项目，而不是选定的项目- Primefaces

EN

<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>**

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);
}

@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;

    }
}