This week's book giveaway is in the Other Open Source APIs forum. We're giving away four copies of Storm Applied and have Sean Allen, Peter Pathirana & Matthew Jankowski on-line! See this thread for details.
Can you elaborate on "open a URL from standalone java program."?
If you want to display the URL page in a Java application, you need to use the JEditorPane or something similar.
If you want to open the URL page using the system's registered application, like a browser, search the forum. Like I said this question comes up quite frequently.