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Missing a piece of code used to compare an in-putted string with a key string  RSS feed

 
Alice Hampton
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I have a method for a button so when a user inputs something it then will get the string value and check it against the string value within the properties file to see if it exists.
I will post my button and method below and hopefully a fresh pair of eyes can see what I need to add so this does as it should

The properties file is called GitCommands.properties that contains -- > key = value <-- in it
I realised I have not used it correctly hence why I keep getting errors - I am lost on how to use it, I think perhaps that may be the issue here? I need to reference the file but I am doing it wrong?
When I do use that piece of code I get null pointer exception too

This is my button:




This is the code for my method:


I understand I am missing my piece of code where it states " //determine whether the string is equal to the property file key string" I understand the logic fine but not actually coding it,could anyone lend a hand?
 
Swastik Dey
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this is not the way you compare a String, it should be

 
Alice Hampton
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Ah of course, thank you, I've been looking at this for far too long now I think! :P I'll be very happy once I've got this finished

Still confused as to why this doesn't work
 
Swastik Dey
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Provide us some more input so that we can try to figure it out.
 
Alice Hampton
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I added some more information, I hope it helps to solve my issue - I believe I know it but I don't know how to fix it
 
Swastik Dey
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So far as I understood, you have a property file. User enters a key to search, if this key is found, in the property file, you display a success message or else you display message. Is this what you want?
 
Alice Hampton
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Yeah that is what I want to be able to do

Would it something more like this that I would use? -> GitCommands.containsKey("Key");
 
Swastik Dey
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Alice Hampton
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So in theory now, if my button has never changed and my method now looks like this:



*Update : It didn't work I still get given a null pointer exception even using that piece of code you you showed me how to use correctly

Thank you for helping, much appreciated by the way
 
Swastik Dey
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You are still doing it wrong. Try this



and make sure GitCommands is not null.
 
Alice Hampton
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It still says:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at HelpSystem.FindSelectedKey(HelpSystem.java:382)


line 382 is:


It always stops at that point in debug- I wanted to check to see if it was definitely that

 
Swastik Dey
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GitCommands seems to be null.
 
Alice Hampton
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In order to fix that would I have to make it as static final Properties rather than just properties as I did have it set up like that at one point
 
Swastik Dey
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Show the complete code if you can.
 
Alice Hampton
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This is my full code - I have a fully functional Jtree with key commands in on it. I hope this makes sense to you, I cut some imports out as it was just stuff to do with components out the designer such as jscrollpane and such, thankyou for helping,let me know if I should cut the code down some more!


 
Swastik Dey
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I made it bit simpler, see if this helps

 
Alice Hampton
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One sec i'll check again
 
Swastik Dey
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I have used simple flowlayout with a size 200,200. You need to maximize the window to provide the input. Once input is given the key you wish to search, press the button , minimize the window and see what it shows in console.
 
Alice Hampton
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Yeah that worked - I just need to incorporate that into my application now as I have a split tabbed,split screen app.

One tab is a search, other is a lookup containing a Jtree then down the right I have my panel

Thanks for taking the time to help me on this,you've really helped!
 
Swastik Dey
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You are welcome.
 
Alice Hampton
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Very helpful, If I ever get stuck again I'm asking you haha, but no in all seriousness my code works great now!
 
Swastik Dey
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That's great. It's good to know that your code is working great now.
 
It is sorta covered in the JavaRanch Style Guide.
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