Sample code for taking user input from Shell

/**
 * Sample code for taking input from Shell demonstrating 
 * string and int input
 * For simple programs or testing purpose its not always 
 * required to take input thru GUI.
 *
 * @author  aj.wh.ca
 * #link 	www.swiftthoughts.com
 */

import java.io.*;

public class ShellUtils
{
      //get String or simply enter from shell
      public static String getStringFromShell(String prompt)
      {
            try
            {
                  System.out.print(prompt);
                  return new BufferedReader(new InputStreamReader(System.in)).readLine();		
            }
            catch (IOException e)
            {
                  e.printStackTrace();
            }
            return null ;
      }

      // get an int. Keep asking until not
      public static int getIntFromShell(String prompt)
      {
            String line = "" ;
            int num = 0 ;
            while(line.equals(""))
            {
                  line = getStringFromShell(prompt);
                  try
                  {
                        num = Integer.parseInt(line);
                  }
                  catch(NumberFormatException e)
                  {
                        System.out.println("Error: Invalid number");
                        line = "" ;
                  }
            }
            return num ;
      }

      // similiar methods can be made for getting char , double etc

      public static void main(String args[])
      {
            String name = ShellUtils.getStringFromShell("Please enter your name ");
            int age = ShellUtils.getIntFromShell("Please enter your age ");

            System.out.println(name + " is "+ age + " years old !!!");
      }

}