Java Data Type - 如何将字符串数字转换为逗号分隔的整数

import java.math.BigDecimal;
import java.text.NumberFormat;
import java.util.Locale;

public class Main {
  public static void main(String[] args) {
    BigDecimal payment = new BigDecimal("12345.67");
    NumberFormat n = NumberFormat.getCurrencyInstance(Locale.US);
    double doublePayment = payment.doubleValue();
    String s = n.format(doublePayment);
    System.out.println(s);
  }
}