Capping decimal places

[Rageagainst20]

int previous = Integer.parseInt(TxtPrevious.getText());
int current = Integer.parseInt(TxtCurrent.getText());
double cpu = 0.07;
double quart = 20.00;

    
    if (current >= previous) 
    {          
        double sum = (current - previous) * cpu + quart;
          String sAnswer = Double.toString(sum);
                   TxtResult.setText ("£" + sAnswer);
    } 
        else {
                JOptionPane.showMessageDialog(null, "Current reading has to be greater than previous reading", "Billing Error", JOptionPane.ERROR_MESSAGE);
    
        }

The above code takes two values add's 0.07 and 20.00 to it and displays it in a textbox, I was wondering if there was anyway to "cap" the decimals to 2 deimcal places, aka currency format.

[JavaBean]

Check DecimalFormat class.