java如何将金额格式化为带,的金额

public static String toAmount(long price){

List<String> str = new ArrayList<>();

BigDecimal divisor = null;

BigDecimal remainder = null;

BigDecimal dividend =  new BigDecimal(price);

do {

BigDecimal[] result = dividend.divideAndRemainder(new BigDecimal(1000));

divisor = result[0];

remainder = result[1];

dividend = divisor;

str.add(remainder.toString());

} while (divisor.compareTo(new BigDecimal(1000)) > 0);

str.add(divisor.toString());

Collections.reverse(str);

String result = str.stream().reduce((sum,e)->sum += "," +e).get();

System.out.println(result);

return result;

}