Question

I have to validate my user input for an integer value and prompt the user to reenter if an invalid value is entered. Thus far I have put together this method below. i believe the logic is correct but I need to get the user to reenter input again after the error message.

void validateItemquantity() {
    boolean error = true;
    while (error) {
        try{ 
            Integer.parseInt(itemQuantityinput.getText());
            error = false; 
        }
        catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(null, "Item quantity must be a positive number, please reenter");
            error = true; 
        }
    }
}

Part of code from jframe method:

private void bnPurchaseActionPerformed(java.awt.event.ActionEvent evt) {                                           

        String itemCode; 
        int itemQuantity, itemPrice, itemCost, totalCost ;

        validateItemquantity();
        itemCode = itemCodeinput.getText();
        itemQuantity = Integer.parseInt(itemQuantityinput.getText());
        itemPrice = catalog.searchCatalog(itemCode);
        itemCost = payment.calculateItemcost(itemQuantity,itemPrice);
        totalCost = payment.calculateTotalcost(itemCost);

Answer 1

I think the loop should be in the calling method.

boolean validateItemquantity() {
    try{ 
        Integer.parseInt(itemQuantityinput.getText());
        return true; 
    }
    catch (NumberFormatException e) {
        JOptionPane.showMessageDialog(null, "Item quantity must be a positive number, please reenter");
        error = false; 
    }
}

And the calling part should be something like that

while(!validateItemquantity())