Allowing User To Input Until They Want Exit

/* Jessie Garza
* 08 / 18 / 14
* ModCalculator
*/

import java.util.Scanner; // program uses Class Scanner
import javax.swing.JOptionPane;
public class ModCalculator
{
// main method begins execution of Java application

[code]....

I am having troubles with allowing the user to input operations/digits until they want to exit, I have tried looping, but I was unsuccessful, came here hoping to figure this out.Currently I have it ending with Break statements after each switch so that they don't coincide all together.. I can't figure out how to keep the Break statement AND loop to previous code of System.out.println( "Please enter an operand which you would like me to calculate with :");

String st = input.next();
c = st.charAt(0);
System.out.println( "I will need for you to input two integers and I will output the result.");
System.out.print( "Enter first integer to calculate: " ); // prompt
number1 = input.nextInt(); // read first number from user
System.out.print( "Enter second integer to calculate: " ); // prompt
number2 = input.nextInt(); // read second number from user

and allowing it to run through the rest of the program with the options still in tact, while having an if statement of an exit keyword.