限制JFormattedTextField的小数位数（UI外观和数据结构）

Question

private JFormattedTextField getCurrencyJFormattedTextField() {
    NumberFormat format= NumberFormat.getNumberInstance();
    format.setMaximumFractionDigits(4);    
    NumberFormatter formatter= new NumberFormatter(format);
    formatter.setMinimum(0.0);
    formatter.setValueClass(Double.class);
    JFormattedTextField formattedTextField = new JFormattedTextField(formatter);
    return formattedTextField;
}

So, if I explicitly key in "1.23456789"

UI of JFormattedTextField will show "1.2346"

However, when call getValue , the returned value is 1.23456789 , not 1.23461

final double price = (Double)jFormattedTextField.getValue();

Is there any way to WYSIWYG? So that the underlying data structure will be consistence with UI display?

Answer 1

You have to use BigDecimal as your data type. It is specifically created for arbitrary-precision signed decimal numbers.