limit input only two decimal

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Views: 1299 | Replies: 1

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Join Date: Apr 2007

Posts: 32

Reputation: onsir is an unknown quantity at this point

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onsir

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limit input only two decimal

Jan 8th, 2008

hi,
help me, how to make limit input only two decimal, i used jformattedtext.
example : if i input more than two decimal in jformattedtext, then it can't and automatically delete by backspace.

thanks for your help.

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Join Date: Aug 2006

Location: South Africa, Durban

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PoovenM

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Re: limit input only two decimal

Jan 8th, 2008

I'm a bit confused as to what you're saying

But I do understand that you want to only allow real input with two decimal places. If you have a GUI then JFormattedTextField is the class you're looking for and this is how you'd use it:

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NumberFormat real = NumberFormat.getNumberInstance();
real.setGroupingUsed(false);
real.setMaximumFractionDigits(2);
JFormattedTextField dataInput = new JFormattedTextField(real);

where the following imports are required:

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import java.text.NumberFormat;
import javax.swing.JFormattedTextField;

What actually happens is that if you type in a number with too many decimal places, you'd see that the text field would automatically remove them. That's 'cause we .setMaximumFractionDigits(2). We can also automatically enforce that two decimal places must be met by using real.setMinimumFractionDigits(2); and even if the user types 1, the input will change to 1.00 (after the user has changed focus to another GUI component).

I haven't actually tried to do that via a console. I would imagine that unless you read in the value, you wouldn't really know how many decimal places are there... but of course where there is Java there is a way