Netbeans and Beans

Question

This is sort of a Bean question.
I'm using Netbeans form designer to visually create some forms. I want to throw in some customized combo boxes, but still be able to visually place them. There would be no bean-specific events or methods needed, just attributes and methods that I could call from my main app.
From what I've read, the only way to customize a component and still be able to use visual tools to manipulate it is to make it a bean.
So, simple example, if I wanted to do something like this:
class SampleJCB extends JComboBox {
    private int foobar = 0;
    public SampleJCB() {
        super();
        foobar = 15;
}What would I have to do to make it a bean?

Answer 1

To make it a Bean, you must implement java.io.Serializable, and add getXXX and setXXX methods for your private variable foobar. As a bean, the code you've provided would look kinda like this:
class SampleJCB
      extends JComboBox
            implements Serializable {
    private int foobar = 0;
    public SampleJCB() {
        super();
        foobar = 15;
    public int getFoobar(){
        return foobar;
    public void setFoobar(int foobar) {
        this.foobar = foobar;
}Now, if you're interested in persistance of you're ComboBox, you may want to check out the Serializable Fields API, which will give you the details on how to serialize objects, how to write readObject and writeObject methods, how to define which fields are default serializable, etc.
Another thing you should note is that all swing components are already beans. So, JComboBox is itself a bean, and hence, when you create a subclass of JComboBox, it is, in a way, already a bean.