JAVA写的高效中文金额转换程序
闲来无事，突然想自己写个中文金额转换程序，想做到简洁高效优雅，看似简单的需求，做起来不一定就容易，特别是对于中间多个零的情况，还有单位换算。总之看起来还不错，最大可到千兆之上，给大家做个参考。

package com.zsmud.ui;import java.math.BigInteger;import java.text.DecimalFormat;/** * 最大到九千兆之上 * @author Zhengsm * @date 2012/12/10 */public class ToChineseAmount {private static char[] chineseAmt = {'零','壹','贰','叁','肆','伍','陆','柒','捌','玖'};private static char[] units = {'拾','佰','仟'};//i=1,i=2,i=3,i=5,i=6,i=7,i=9,i=10,i=11private static char[] chineseUnits = {'元','万','亿','兆'};//i=0,i=4,i=8，private static char[] smallUnits = {'分','角'};public static String formatInt(BigInteger num) {if(num.equals(BigInteger.ZERO)) return "零元";if(num.toString().length()>16) throw new RuntimeException("too max num");StringBuffer result = new StringBuffer("");BigInteger radix = new BigInteger("10");int i=0;char preChar = 0;while(num.compareTo(BigInteger.ZERO)==1){StringBuffer tmp = new StringBuffer();BigInteger rest = num.mod(radix);num = num.divide(radix);if(rest.equals(BigInteger.ZERO) && preChar!='零' && inArray(chineseAmt,preChar)){tmp.append('零');}else if(!rest.equals(BigInteger.ZERO)){tmp.append(chineseAmt[rest.intValue()]);if(i%4!=0) tmp.append(units[i%4-1]);}if(i%4==0) {if(i/4>0&&inArray(chineseUnits,result.charAt(0))) result.delete(0,1);if(tmp.length()>0 && tmp.charAt(0)=='零') tmp.insert(0, chineseUnits[i/4]);elsetmp.append(chineseUnits[i/4]);}preChar = tmp.length()>0? tmp.charAt(0):0;i++;result.insert(0, tmp);}return result.toString();}public static String formatSmall(int small){if(small>100) throw new RuntimeException("too small");StringBuffer result = new StringBuffer("");char preChar = 0;int i=0;while(small>0){StringBuffer tmp = new StringBuffer();int rest = small%10;small = small/10;if(rest==0 && preChar!='零' && inArray(chineseAmt,preChar)){tmp.append('零');}else if(rest!=0){tmp.append(chineseAmt[rest]);tmp.append(smallUnits[i]);}preChar = tmp.length()>0? tmp.charAt(0):0;i++;result.insert(0, tmp);}return result.toString();}private static boolean inArray(char[] array,char c){for(char ch : array){if(ch == c) return true;}return false;}public static String format(double num){DecimalFormat df = new DecimalFormat("#.00");String input = df.format(num);StringBuffer sb = new StringBuffer();if(input.indexOf('.')!=-1) {sb.append(formatInt(new BigInteger(input.substring(0, input.indexOf('.')))));sb.append(formatSmall(Integer.parseInt(input.substring(input.indexOf('.')+1))));}return sb.toString();}public static void main(String[] args){System.out.println(formatInt(new BigInteger("909")));System.out.println(formatInt(new BigInteger("9009")));System.out.println(formatInt(new BigInteger("9099")));System.out.println(formatInt(new BigInteger("909099")));System.out.println(formatInt(new BigInteger("909909")));System.out.println(formatInt(new BigInteger("909999")));System.out.println(formatInt(new BigInteger("90909999")));System.out.println(formatInt(new BigInteger("900090019001921")));System.out.println(formatInt(new BigInteger("900090009000")));System.out.println(formatInt(new BigInteger("90909000")));System.out.println(formatInt(new BigInteger("90999009")));System.out.println(formatInt(new BigInteger("909009009")));System.out.println(formatInt(new BigInteger("9009909009009")));System.out.println(formatInt(new BigInteger("9009009909009009")));System.out.println(formatSmall(78));System.out.println(format(9999990999999.99));System.out.println(format(9999990999999.00));}}