xception in thread "main" java.lang.NumberFormatException: For input string: "13.7" code example

Example: exception in thread "main" java.lang.numberformatexception: for input string: ""

int number = 0; // or any application default value
try {
	number = Integer.parseInt(input);
} catch (NumberFormatException nfe) {
	// do whatever you need to do if you get an invalid number
	// you can put the try catch in a loop and keep asking for a 
    // value until you don't get a valid one
    
  	// If you want to use the default value in case of an
    // invalid number you can do nothing in here
}