package util;

import java.util.Random;
import java.util.Stack;

/**
 * Created by ldh on 2019年1月17日.
 */
public class BankCardNoUtil {

 public String createICBCBankCardNo() {
 return credit_card_number(new String[]{"621226"}, 19, 1)[0];
 }

 public String createICBCBankCardNo(boolean isEvent) {
 String cardNumber = "";
 boolean isNext = false;
 do {
 cardNumber = credit_card_number(new String[]{"621226"}, 19, 1)[0];
 if ((Integer.parseInt(cardNumber.substring(18)) % 2 == 0 && isEvent) || (Integer.parseInt(cardNumber.substring(18)) % 2 != 0 && !isEvent)) {
 return cardNumber;
 } else {
 isNext = true;
 }
 } while (isNext);
 return cardNumber;
 }

 public String[] credit_card_number(String[] prefixList, int length, int howMany) {
 Stack<String> result = new Stack<String>();
 for (int i = 0; i < howMany; i++) {
 int randomArrayIndex = (int) Math.floor(Math.random() * prefixList.length);
 String ccnumber = prefixList[randomArrayIndex];
 result.push(completed_number(ccnumber, length));
 }
 return result.toArray(new String[result.size()]);
 }

 public String completed_number(String string, int length) {
 int l = length - string.length();
 String result = string;
 Random r = new Random();
 for (int i=0; i<l; i++) {
 int randomArrayIndex = r.nextInt(10);
 result += randomArrayIndex+"";
 }
 return result;
 }

 public static void main(String[] args) {
 BankCardNoUtil bankCardNoUtil = new BankCardNoUtil();
 for (int i=0; i<100; i++) {
 String code = bankCardNoUtil.createICBCBankCardNo();
 System.out.println("code:" + code + "," + code.length());
 }
 }
}