BATHTHAI

import java.math.BigDecimal;
import java.math.BigInteger;

/**
 * author (JS) Earthchie http://www.earthchie.com/ 
 * modify (Java) Falook http://www.falook.in.th/ 
 * license WTFPL v.2 - http://www.wtfpl.net/
 *
 * Copyright (c) 2014, Earthchie (earthchie@gmail.com)
 */
public class Helper {
    private static final String BATH_SUFFIX = "บาท";
    public static BigInteger parseInt(String num){
        return new BigInteger(num);
    }
    public static BigDecimal parseDecimal(String num){
        return new BigDecimal(num);
    }
    public static int charToInt(char a) {
        return Integer.parseInt(a + "");
    }
    public static String bahtThai(String number) {
        return bahtThai(number, "");
    }  
    public static String bahtThai(String number,String suffix) {
        return bahtThai(number, suffix,true);
    }    
    public static String bahtThai(String number,boolean forceZero) {
        return bahtThai(number, "",forceZero);
    }
    public static String bahtThai(String num, String suffix,boolean forceZero) {        
        String t[] = {"", "สิบ", "ร้อย", "พัน", "หมื่น", "แสน", "ล้าน"};
        String n[] = {"", "หนึ่ง", "สอง", "สาม", "สี่", "ห้า", "หก", "เจ็ด", "แปด", 
            "เก้า"};
        String text = "";
        num = num.replace(",", "");
        suffix = suffix.equals("") ?BATH_SUFFIX:suffix;         
        if(parseDecimal(num).toString().equals("0") && forceZero)
            return "ศูนย์"+BATH_SUFFIX;        
        if (num.contains(".")) {
            String parts[] = num.split("\\.");
            parts[1] = (parseDecimal("0."+parts[1]).setScale(2, BigDecimal.ROUND_HALF_UP))
                .toString().split("\\.")[1];
            if (forceZero)               
                return bahtThai(parts[0],"") + bahtThai(parts[1], "สตางค์");
            else
                return bahtThai(parts[1], "สตางค์");            
        }
        if (num.length() > 7)
            return bahtThai(num.substring(0, num.length() - 6), "ล้าน",false).replace(BATH_SUFFIX,"ล้าน")
                    + bahtThai(num.substring(num.length() - 6, num.length()),"",false);
        else
            for (int i = 0; i < num.length(); i++) 
                if (Integer.parseInt(num.charAt(i) + "") != 0) 
                    if (num.length() > 2 && i == num.length() - 1
                            && charToInt(num.charAt(i)) == 1
                            && !suffix.equals("สตางค์")) 
                        text += "เอ็ด" + t[num.length() - 1 - i];
                    else 
                        text += n[charToInt(num.charAt(i))] + 
                                t[num.length() - 1 - i];           
                
        text = text.replace("หนึ่งสิบ", "สิบ");
        text = text.replace("สองสิบ", "ยี่สิบ");
        text = text.replace("สิบหนึ่ง", "สิบเอ็ด");        
        return text + suffix;
    }
    public static void main(String[] args) {
        System.out.printf("%-25s %s\n" ,"0", bahtThai("0"));
        System.out.printf("%-25s %s\n" ,"0.25", bahtThai("0.25"));
        System.out.printf("%-25s %s\n" ,"0.256", bahtThai("0.256"));
        System.out.printf("%-25s %s\n" ,"0.2514", bahtThai("0.2514"));
        System.out.printf("%-25s %s\n" ,"12,000.50", bahtThai("12,000.50"));
        System.out.printf("%-25s %s\n" ,"1,200,000.50", bahtThai("1,200,000.50"));
        System.out.printf("%-25s %s\n" ,"12,100,000,000,000.50", bahtThai("12,100,000,000,000.50"));
        System.out.printf("%-25s %s\n" ,"12,100,000.50", bahtThai("12,100,000.50"));
        System.out.printf("%-25s %s\n" ,"000,000,000,000.25", bahtThai("000,000,000,000.25"));        
        System.out.printf("%-25s %s\n" ,"0.25 [forceZero = false]", bahtThai("0.25",false));
        System.out.printf("%-25s %s\n" ,"0.256 [forceZero = false]", bahtThai("0.256",false));
    }
}