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The moose likes Developer Certification (SCJD/OCMJD) and the fly likes Numeric/Alphabetic chars Big Moose Saloon
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Numeric/Alphabetic chars

David Sham
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Joined: Apr 19, 2005
Posts: 61
Does the JDK have anything in the API for determining numeric vs. alpabetic characters? In my client, I prevent the user from typing anything but numbers for the fields that require numbers. But I do this by manually running through a string array of numbers (0 - 9) and checking each character typed via a KeyListener. If the character typed is not a numeric, then the KeyEvent is consumed. It works fine functionally, but is there anything in the JDK that would decipher numeric from alphabetic characters for me? I have not seen anything that would do this.
Frans Janssen
Ranch Hand

Joined: Dec 29, 2004
Posts: 357
Hi David,

If you want only to allow certain strings as valid input to a textfield, the standard way to achieve that, would be to use a JFormattedTextField with an appropriate AbstractFormatter-subclass or a Format-subclass.


Tom Henricksen
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Joined: Mar 23, 2004
Posts: 136

Could you use a regular expression? Is using java.util.regex allowed on the SCJD? I have used regular expressions for stuff like this numerous times.
I agree. Here's the link:
subject: Numeric/Alphabetic chars
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