3. When you enter characters at a keyboard, the system must retain them in the order in which you typed them. It could use a queue for this purpose. Once the characters are in a queue, the system can process them as necessary. For example, if you had typed an integer-without any mistakes, but possibly preceded or followed by blanks -the queue would contain digits and possibly blanks. If the digits are 2, 4, and 7, entered as 2 4 7" (notice the spaces all over the place), the system should convert them into a decimal value 247 Implement a Java method convertToNumber that uses a queue to convert a sequence of character digits into an integer. You can assume that only digits and spaces are entered by the user. Example method specification: public static int convert ToNumber (string str) Make your methods fail-safe, i.e handle exceptions (try/catch) or use if/else statements for error testing/avoidance wherever appropriate