Server-side Java sports numerous frameworks built on top of J2EE to help encapsulate common application concerns, making the development process more effective. Client-side Java frameworks started to emerge much slower: Only in the past two years did client-side frameworks finally start to simplify rich-client Java development.

One such framework, JAXX, allows you to specify a Swing UI in XML:

JAXX enables you to write simple XML files describing components and their interactions, and then compile those XML files into ordinary Java classes. User interface components can be developed much faster and more easily in JAXX than in ordinary Java code.

<Application title='Calculator'>
  <style source='Calculator.css'/>
  <script source='Calculator.script'/>
</Application>

Application {
    lookAndFeel: system;
}

#display {
    background: #BCE5AD;
    opaque: true;
    horizontalAlignment: right;
    border:    {BorderFactory.createBevelBorder(BevelBorder.LOWERED)};
    font-size: 22;
    font-weight: bold;
}

JButton {
    font-size: 18;
    width: 60;
    height: 35;
}

JButton.digit {
    foreground: blue;
}

The more usual Swing approach to changing a component's look-and-feel is to specify, well, a new look-and-feel for your application. Using CSS is a more direct approach, but I always had the sense that using XML to describe UIs creates GUIs that look generic, not to mention that introducing XML can make Swing development even more complex. However, JAXX's approach might still be useful, since CSS is so widely used.

What do you think of JAXX's approach to Swing styling?