Why do I get NoClassDefFoundError: java/awt/Desktop?

Question

I\'m trying to open an URI with Swing that I get above error.

What is the reason and how can I fix it?

When I do it in console everything is OK but

Answer 1

NoClassDefFoundError can only be caused by a classpath problem.

Because Desktop is part of jre, make sure that your classpath contains a reference to the jre library.

In Eclipse, you can go to run configurations --> Classpath and check there

UPDATE:

As Andrew suggested, you can also check you have at least java 1.6