Android draw9patch throws NoClassDefFoundError
<p>I upgraded to Android SDK Tools r8 today and I can't seem to run the draw9patch tool.  I'm getting the following error:</p>

<pre><code>Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: org/jdesktop/swingworker/SwingWorker
at com.android.draw9patch.Application$1.run(Application.java:48)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:633)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Caused by: java.lang.ClassNotFoundException: org.jdesktop.swingworker.SwingWorker
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at sun.misc.Launcher$ExtClassLoader.findClass(Launcher.java:229)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
... 9 more
</code></pre>

<p>I'm running snow leopard and have jre (or jdk?) 1.6.</p>

<p>Any ideas how to get this working?  Thanks!</p>
