How to take into account different screen sizes?

I have written a JAV开发者_运维知识库A desktop application using Netbeans IDE, when I run the application it looks perfect on my laptop. However when I installed it on a larger screen laptop, there is some extra space. What is the best way to get rid of that? Is there a way I can support multiple screen sizes in my source code or should I create a copy of the project and install netbeans and do the resize at the new computer which defeats the whole purpose?!

thanks

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If you are using Swing, you can use any of the different layout managers. http://download.oracle.com/javase/tutorial/uiswing/layout/using.html