银行卡号Luhm校验Java实现代码

 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 public class CheckBankNumber {

     //Description:  银行卡号Luhm校验

     //Luhm校验规则：16位银行卡号（19位通用）:

     // 1.将未带校验位的 15（或18）位卡号从右依次编号 1 到 15（18），位于奇数位号上的数字乘以 2。
     // 2.将奇位乘积的个十位全部相加，再加上所有偶数位上的数字。
     // 3.将加法和加上校验位能被 10 整除。

     //开头6位
     //private  final static String strBin = "10,18,30,35,37,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,60,62,65,68,69,84,87,88,94,95,98,99";

     private final static String SUCCESS="true";

     private final static String BAD_LENGTH="银行卡号长度必须在16到19之间";

     private final static String NOT_NUMBER="银行卡必须全部为数字";

     private final static String ILLEGAL_NUMBER="银行卡不符合规则";

     public static String luhmCheck(String bankno){
         if (bankno.length() < 16 || bankno.length() > 19) {
             return BAD_LENGTH;
             }

         Pattern pattern = Pattern.compile("[0-9]*");
         Matcher match = pattern.matcher(bankno);
         if (match.matches() == false) {
             return NOT_NUMBER;
         }

 //        if (strBin.indexOf(bankno.substring(0, 2)) == -1) {
 //        return "银行卡号开头6位不符合规范";
 //        }

         int lastNum=Integer.parseInt(bankno.substring(bankno.length()-1,bankno.length()));//取出最后一位（与luhm进行比较）

         String first15Num=bankno.substring(0,bankno.length()-1);//前15或18位
         //System.out.println(first15Num);
         char[] newArr = new char[first15Num.length()];    //倒叙装入newArr
         char[] tempArr = first15Num.toCharArray();
         for(int i = 0; i < tempArr.length ; i++){
             newArr[tempArr.length-1-i] = tempArr[i];
         }
         //System.out.println(newArr);

         int[] arrSingleNum = new int[newArr.length]; //奇数位*2的积 <9
         int[] arrSingleNum2 = new int[newArr.length];//奇数位*2的积 >9
         int[] arrDoubleNum=new int[newArr.length];  //偶数位数组

         for(int j = 0;j < newArr.length; j++){
             if((j+1)%2==1){//奇数位
                 if((int)(newArr[j]-48)*2<9)
                     arrSingleNum[j]=(int)(newArr[j]-48)*2;
                 else
                     arrSingleNum2[j]=(int)(newArr[j]-48)*2;
             }
             else //偶数位
                 arrDoubleNum[j]=(int)(newArr[j]-48);
         }

         int[] arrSingleNumChild = new int[newArr.length]; //奇数位*2 >9 的分割之后的数组个位数
         int[] arrSingleNum2Child = new int[newArr.length];//奇数位*2 >9 的分割之后的数组十位数

         for(int h=0;h<arrSingleNum2.length;h++){
             arrSingleNumChild[h] = (arrSingleNum2[h])%10;
             arrSingleNum2Child[h] = (arrSingleNum2[h])/10;
         }    

         int sumSingleNum=0; //奇数位*2 < 9 的数组之和
         int sumDoubleNum=0; //偶数位数组之和
         int sumSingleNumChild=0; //奇数位*2 >9 的分割之后的数组个位数之和
         int sumSingleNum2Child=0; //奇数位*2 >9 的分割之后的数组十位数之和
         int sumTotal=0;
         for(int m=0;m<arrSingleNum.length;m++){
             sumSingleNum=sumSingleNum+arrSingleNum[m];
         }

         for(int n=0;n<arrDoubleNum.length;n++){
             sumDoubleNum=sumDoubleNum+arrDoubleNum[n];
         }

         for(int p=0;p<arrSingleNumChild.length;p++){
             sumSingleNumChild=sumSingleNumChild+arrSingleNumChild[p];
             sumSingleNum2Child=sumSingleNum2Child+arrSingleNum2Child[p];
         }      

         sumTotal=sumSingleNum+sumDoubleNum+sumSingleNumChild+sumSingleNum2Child;

         //计算Luhm值
         int k= sumTotal%10==0?10:sumTotal%10;
         int luhm= 10-k;

         if(lastNum == luhm){
             return SUCCESS;//验证通过
         }
         else{
             return ILLEGAL_NUMBER;
         }
     }

     public static void main(String[] args) {
         String bankno = "6214857110432079";
         System.out.println(bankno+":"+luhmCheck(bankno));
         String bankno1 = "6212164000046323291";
         System.out.println(bankno1+":"+luhmCheck(bankno1));
         String bankno2 = "6222023104004123546";
         System.out.println(bankno2+":"+luhmCheck(bankno2));
     }
 }