You need to surround the call to Integer.parseInt()
with a try/catch block to detect invalid input, like:
try {
number = Integer.parseInt(stringInput);
} catch (NumberFormatException e) {
// Not a number, display error message...
}
Here is a solution:
String errorMessage = "";
do {
// Show input dialog with current error message, if any
String stringInput = JOptionPane.showInputDialog(errorMessage + "Enter number.");
try {
int number = Integer.parseInt(stringInput);
if (number > 10 || number < 0) {
errorMessage = "That number is not within the \n" + "allowed range!\n";
} else {
JOptionPane
.showMessageDialog(null, "The number you chose is " + number + ".");
errorMessage = ""; // no more error
}
} catch (NumberFormatException e) {
// The typed text was not an integer
errorMessage = "The text you typed is not a number.\n";
}
} while (!errorMessage.isEmpty());