Hi there! I currently have a JSF application that uses two listboxes. The first, say ListBox1, contains a list of manufacturers; each option comes from the database (via a method getManufacturers in a class called QueryUtil), is populated dynamically, and its value is an integer ID. This part works so far.

My goal is to populate a second listbox, say ListBox2, with a list of products sold by the manufacturer. This list of products will come from the database as well (products are linked to a manufacturer via a foreign key relationship, via a method getProducts in my QueryUtil class). How do I go about doing this? Please bear in mind that I've been working with JSF for under 24 hours; I'm willing to accept the fact that I'm missing something very rudimentary.

Again, I've been able to populate the list of manufacturers just fine; unfortunately, adding the Products component gives me java.lang.IllegalArgumentException: argument type mismatch

faces-config.xml

<managed-bean>
  <managed-bean-name>ProductsBean</managed-bean-name>
  <managed-bean-class>com.nieltown.ProductsBean</managed-bean-class>
  <managed-bean-scope>request</managed-bean-scope>
  <managed-property>
    <property-name>manufacturers</property-name>
    <property-class>java.util.ArrayList</property-class>
    <value>#{manufacturers}</value>
  </managed-property>
  <managed-property>
    <property-name>selectedManufacturer</property-name>
    <property-class>java.lang.Integer</property-name>
    <value>#{selectedManufacturer}</value>
  </managed-property>
  <managed-property>
    <property-name>products</property-name>
    <property-class>java.util.ArrayList</property-class>
    <value>#{products}</value>
  </managed-property>
  <managed-property>
    <property-name>selectedProduct</property-name>
    <property-class>java.lang.Integer</property-name>
    <value>#{selectedProducts}</value>
  <managed-property>
</managed-bean>

com.nieltown.ProductsBean

public class ProductsBean {

  private List<SelectItem> manufacturers;
  private List<SelectItem> products;
  private Integer selectedManufacturer;
  private Integer selectedProduct;

  public ProductsBean() {}

    public Integer getSelectedManufacturer(){

        return selectedManufacturer;

    }

    public void setSelectedManufacturer(Integer m){

        selectedManufacturer = m;

    }

    public Integer getSelectedProduct(){

        return selectedProduct;

    }

    public void setSelectedProduct(Integer p){

        selectedProduct = p;

    }  

    public List<SelectItem> getManufacturers(){

        if(manufacturers == null){
            SelectItem option;
            plans = new ArrayList<SelectItem>();
            QueryUtil qu = new QueryUtil();
            Map<Integer, String> manufacturersMap = qu.getManufacturers();
            for(Map.Entry<Integer, String> entry : manufacturersMap.entrySet()){
                option = new SelectItem(entry.getKey(),entry.getValue());
                manufacturers.add(option);

            }
        }
        return manufacturers;

    }

    public void setManufacturers(List<SelectItem> l){

        manufacturers = l;

    }

    public List<SelectItem> getProducts(){

        if(products == null){
            SelectItem option;
            products = new ArrayList<SelectItem>();
            if(selectedPlan != null){
                PMTQueryUtil pqu = new PMTQueryUtil();
                Map<Integer, String> productsMap = pqu.getProducts();
                for(Map.Entry<Integer, String> entry : productsMap.entrySet()){
                    option = new SelectItem(entry.getKey(),entry.getValue());
                    products.add(option);
                }
            }
        }
        return products;
    }

    public void setProducts(List<SelectItem> l){

        products = l;

    }
}

JSP fragment

<h:selectOneListbox id="manufacturerList"
    value="#{ProductsBean.selectedManufacturer}"
    size="10">
    <f:selectItems value="#{ProductsBean.manufacturers}" />
</h:selectOneListbox>
<h:selectOneListbox id="productList"
    value="#{PendingPlansBean.selectedProduct}"
    size="10">
    <f:selectItems binding="#{ProductsBean.products}" />
</h:selectOneListbox>