Question

In a Screen to be rendered by a JSF Implementation, I had to show a static drop down or list box (which means the values are not changing ), So I decided to use a list of select Items and in the getter of the List , I am populating all the select Items as this

List.add(new SelectItem(VALUE,TEXT)) and so on.. 

If I used this way – What are the pitfalls? I made this List static since this will be common for all the Request Scoped Beans the JSF Implementation creates. Is this okay to do?

Sometimes , the items are added twice if multiple requests are fired.Is there an Application Scope ? or Whats the standard way of doing these stuff?

I’m also looking into API.Sometimes SO is quicker.

I’m using JSF Apace My Faces 1.2 without Tomahawk or any extra libs

Thanks,

Answer 1

Sometimes , the items are added twice if multiple requests are fired.

This indicates that you’re adding the items in the getter method like follows

public class Bean {
    private List<SelectItem> items = new ArrayList<SelectItem>();

    public List<SelectItem> getItems() {
        items.add(new SelectItem("value1", "label1"));
        items.add(new SelectItem("value2", "label2"));
        items.add(new SelectItem("value3", "label3"));
        return items;
    }
}

This is not good. A javabean getter should have the sole purpose to return a bean property or at highest do lazy loading, not to do some business stuff. You should create and fill the list during bean construction

public class Bean {
    private List<SelectItem> items;

    public Bean() {
        items = new ArrayList<SelectItem>();
        items.add(new SelectItem("value1", "label1"));
        items.add(new SelectItem("value2", "label2"));
        items.add(new SelectItem("value3", "label3"));
    }
}

or initialization

public class Bean {
    private List<SelectItem> items;

    {
        items = new ArrayList<SelectItem>();
        items.add(new SelectItem("value1", "label1"));
        items.add(new SelectItem("value2", "label2"));
        items.add(new SelectItem("value3", "label3"));
    }
}

or @PostConstruct

public class Bean {
    private List<SelectItem> items;

    @PostConstruct
    public void init() {
        items = new ArrayList<SelectItem>();
        items.add(new SelectItem("value1", "label1"));
        items.add(new SelectItem("value2", "label2"));
        items.add(new SelectItem("value3", "label3"));
    }
}

Is there an Application Scope ?

There is. Just use <managed-bean-scope>application</managed-bean-scope>.

or Whats the standard way of doing these stuff?

An application scoped bean is the way to go.

See also:

• Why does JSF call getters multiple times?