Question

I’m writing a simple loan calculator with gui using swing. I used DecimalFormat to make sure I capture the input in my specified format ####.## for my JFormattedTextField .

public static void main(String[] args) {
    JFormattedTextField loanAmountField = new JFormattedTextField(new DecimalFormat("####.##"));
    JFormattedTextField interestRateField = new JFormattedTextField(new DecimalFormat("####.##"));
    JFormattedTextField yearField = new JFormattedTextField(new DecimalFormat("####.##"));
    JFormattedTextField monthlyPaymentField = new JFormattedTextField(new DecimalFormat("####.##"));
}

When the user press my “calculate” button, it calculates and displays the monthlyPaymentField.

To test if my program will even display it correctly, I tried assigning monthlyPaymentField a value of 12.22, but I’m getting an error that says monthlyPaymentField should be declared as a double.

class CalculateListener implements ActionListener {
public CalculateListener (JFormattedTextField loanAmountField, JFormattedTextField     monthlyPaymentField, JFormattedTextField interestRateField, JFormattedTextField yearField, int monthlyTest)
{
  this.interestRateField = interestRateField;   
  this.yearField = yearField;
  this.loanAmountField = loanAmountField;
  this.monthlyPaymentField = monthlyPaymentField;
  this.monthlyTest = monthlyTest;
}

public void actionPerformed(ActionEvent event){

   monthlyPaymentField = 12.22;

    }

}

How do I go about this so that I can still use my JFormattedTextField with DecimalFormat but can still display a Float on my monthlyPaymentField?

Answer 1

You can use the setValue method for this;

monthlyPaymentField.setValue(new Double(12.22));