Money converter

AmountConverter is a generalized class which contains methods for getting the amount into words depending on the Indian or foreign Currency as well.

package fos;
import fos.ReportsConstants;
public class AmountConverter {
 private static AmountConverter instance = null;
 //public static String CURRENCY_INR = FOSConstants.LOCAL_CURR_CD;
 public static String CURRENCY_INR = "INR";//Indian rupees
 
 /**
  * Method getInstance.
  * @return AmountConverter
  */
 public static AmountConverter getInstance(){
  if(null == instance){
   instance = new AmountConverter();
  }
  return instance;
 }
 
 /**
  * Ref 001
  * Method getAmountInWords returns the amount in word
  * for a number input in BSES format.
  * @param astrAmount
  * @return String
  */
 public String getAmountInWords(String astrAmount, String strCurrCd){
  StringBuffer sbfAmtInWords = new StringBuffer();
  char ch;
  if (strCurrCd.equals(CURRENCY_INR)){
   sbfAmtInWords.append(ReportsConstants.RUPEES);
  }else{
   sbfAmtInWords.append(strCurrCd);
  }
  sbfAmtInWords.append(ReportsConstants.SPACE);
  
  for (int i = 0; i < astrAmount.length(); i++) {
   ch = astrAmount.charAt(i);
   switch (ch) {
    case '0': 
     sbfAmtInWords.append(ReportsConstants.ZERO);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '1': 
     sbfAmtInWords.append(ReportsConstants.ONE);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '2': 
     sbfAmtInWords.append(ReportsConstants.TWO);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '3': 
     sbfAmtInWords.append(ReportsConstants.THREE);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '4': 
     sbfAmtInWords.append(ReportsConstants.FOUR);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '5': 
     sbfAmtInWords.append(ReportsConstants.FIVE);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '6': 
     sbfAmtInWords.append(ReportsConstants.SIX);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '7': 
     sbfAmtInWords.append(ReportsConstants.SEVEN);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '8': 
     sbfAmtInWords.append(ReportsConstants.EIGHT);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '9': 
     sbfAmtInWords.append(ReportsConstants.NINE);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    case '.': 
     sbfAmtInWords.append(ReportsConstants.AND);
     sbfAmtInWords.append(ReportsConstants.SPACE);
     if (strCurrCd.equals(CURRENCY_INR)){
      sbfAmtInWords.append(ReportsConstants.PAISE);
     }else{
      sbfAmtInWords.append(ReportsConstants.COINS);
     }
     sbfAmtInWords.append(ReportsConstants.SPACE);
     break;
    default :
     break;
   }
  }
  sbfAmtInWords.append(ReportsConstants.ONLY);
  return sbfAmtInWords.toString();
 }
 
 
 public String getAmountInWords(String astrAmount){
  return getAmountInWords(astrAmount, CURRENCY_INR);
 }
}