/**
 * 數字金額大寫轉換，思想先寫個完整的然後將如零拾替換成零 要用到正則表示式
 */
public static String digitUppercase(double n) {
	String fraction[] = {"角", "分"};
	String digit[] = {"零", "壹", "貳", "叄", "肆", "伍", "陸", "柒", "捌", "玖"};
	String unit[][] = {{"元", "萬", "億"}, {"", "拾", "佰", "仟"}};

	String head = n < 0 ? "負" : "";
	n = Math.abs(n);

	String s = "";
	for (int i = 0; i < fraction.length; i++) {
		s += (digit[(int) (Math.floor(n * 10 * Math.pow(10, i)) % 10)] + fraction[i]).replaceAll("(零.)+", "");
	}
	if (s.length() < 1) {
		s = "整";
	}
	int integerPart = (int) Math.floor(n);

	for (int i = 0; i < unit[0].length && integerPart > 0; i++) {
		String p = "";
		for (int j = 0; j < unit[1].length && n > 0; j++) {
			p = digit[integerPart % 10] + unit[1][j] + p;
			integerPart = integerPart / 10;
		}
		s = p.replaceAll("(零.)*零$", "").replaceAll("^$", "零") + unit[0][i] + s;
	}
	return head + s.replaceAll("(零.)*零元", "元").replaceFirst("(零.)+", "").replaceAll("(零.)+", "零").replaceAll("^整$", "零元整");
}
 

方法二：

private void number2Invoice(int num) {
		//12345
		String mark[] = new String[] {"","十","百","千","萬","十","百","千","億","十","百","千","萬"};
		String numCn[] = new String[] {"零","一","二","三","四","五","六","七","八","九"};
		
		char[] numArrRev = String.valueOf(num).toCharArray();
		
		StringBuffer container = new StringBuffer();
		for (int i = 0; i < numArrRev.length; i++) {
			Integer val = Integer.valueOf(String.valueOf(numArrRev[i]));
			String number = numCn[ val ];
			int x  = numArrRev.length -i -1;
			String sign =  mark[x];
			
			if( val == 0) {
			 if( x % 4 !=0){// 刪除單位
                 sign = "";
             }
             if(i < numArrRev.length-1){
                 Integer val1 = Integer.parseInt(String.valueOf(numArrRev[i+1]));
                 if( val==0 && val==val1 ){
                	 number = "";
                 }else if ( val == 0 && ("萬".equals(sign) || "億".equals(sign))) {
                	 number = "";
                 }
             }else if(i == numArrRev.length-1){
            	 number = "";
             }
			}
			
			container.append(number + sign);
		}
		
		System.out.println( num + "-->" + container.toString() );
	}