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Working with GUIs throwing Exception in thread “main” java.lang.NullPointerException [duplicate]  RSS feed

 
Greenhorn
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I am working on a library management system program in Eclipse IDE. I am developing the GUIs but I am getting below nullPointerException error. I want to create a four JButton (Manage Material, Manage Patron, Load Data, Exit) button in my homepage and link with sub-menus.

The console error.




Below is the source code.

 
Rancher
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Android Eclipse IDE Java Java ME
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exitPanel is not initialized, leading to the exception.
 
Abdul Haq Sultani
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Thanks Swastik! that was the issue. I never created an object of exitButton.
 
Marshal
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Don't make your class a subclass of JFrame. A library IS‑NOT‑A frame; a library appliication HAS‑A frame.
Please learn how to break lines. your line 81 for example is too long to read. There is useful information in the old Sun style guide.
 
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