1 import java.util.regex.Matcher;  2 import java.util.regex.Pattern;  3   4 public class CheckBankNumber {  5   6   7     //Description:  银行卡号Luhm校验  8   9     //Luhm校验规则：16位银行卡号（19位通用）: 10      11     // 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。 12     // 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。 13     // 3.将加法和加上校验位能被 10 整除。 14      15      16     //开头6位 17     //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"; 18  19     private final static String SUCCESS="true"; 20      21     private final static String BAD_LENGTH="银行卡号长度必须在16到19之间"; 22      23     private final static String NOT_NUMBER="银行卡必须全部为数字"; 24      25     private final static String ILLEGAL_NUMBER="银行卡不符合规则"; 26      27     public static String luhmCheck(String bankno){ 28         if (bankno.length() < 16 || bankno.length() > 19) { 29             return BAD_LENGTH; 30             } 31          32         Pattern pattern = Pattern.compile("[0-9]*"); 33         Matcher match = pattern.matcher(bankno); 34         if (match.matches() == false) { 35             return NOT_NUMBER; 36         } 37          38 //        if (strBin.indexOf(bankno.substring(0, 2)) == -1) { 39 //        return "银行卡号开头6位不符合规范"; 40 //        } 41          42         int lastNum=Integer.parseInt(bankno.substring(bankno.length()-1,bankno.length()));//取出最后一位（与luhm进行比较） 43          44         String first15Num=bankno.substring(0,bankno.length()-1);//前15或18位 45         //System.out.println(first15Num); 46         char[] newArr = new char[first15Num.length()];    //倒叙装入newArr 47         char[] tempArr = first15Num.toCharArray(); 48         for(int i = 0; i < tempArr.length ; i++){ 49             newArr[tempArr.length-1-i] = tempArr[i]; 50         } 51         //System.out.println(newArr); 52          53          54         int[] arrSingleNum = new int[newArr.length]; //奇数位*2的积 <9 55         int[] arrSingleNum2 = new int[newArr.length];//奇数位*2的积 >9 56         int[] arrDoubleNum=new int[newArr.length];  //偶数位数组 57          58         for(int j = 0;j < newArr.length; j++){ 59             if((j+1)%2==1){//奇数位 60                 if((int)(newArr[j]-48)*2<9) 61                     arrSingleNum[j]=(int)(newArr[j]-48)*2; 62                 else 63                     arrSingleNum2[j]=(int)(newArr[j]-48)*2; 64             } 65             else //偶数位 66                 arrDoubleNum[j]=(int)(newArr[j]-48); 67         } 68          69         int[] arrSingleNumChild = new int[newArr.length]; //奇数位*2 >9 的分割之后的数组个位数 70         int[] arrSingleNum2Child = new int[newArr.length];//奇数位*2 >9 的分割之后的数组十位数 71          72         for(int h=0;h<arrSingleNum2.length;h++){ 73             arrSingleNumChild[h] = (arrSingleNum2[h])%10; 74             arrSingleNum2Child[h] = (arrSingleNum2[h])/10; 75         }     76          77         int sumSingleNum=0; //奇数位*2 < 9 的数组之和 78         int sumDoubleNum=0; //偶数位数组之和 79         int sumSingleNumChild=0; //奇数位*2 >9 的分割之后的数组个位数之和 80         int sumSingleNum2Child=0; //奇数位*2 >9 的分割之后的数组十位数之和 81         int sumTotal=0; 82         for(int m=0;m<arrSingleNum.length;m++){ 83             sumSingleNum=sumSingleNum+arrSingleNum[m]; 84         } 85          86         for(int n=0;n<arrDoubleNum.length;n++){ 87             sumDoubleNum=sumDoubleNum+arrDoubleNum[n]; 88         } 89          90         for(int p=0;p<arrSingleNumChild.length;p++){ 91             sumSingleNumChild=sumSingleNumChild+arrSingleNumChild[p]; 92             sumSingleNum2Child=sumSingleNum2Child+arrSingleNum2Child[p]; 93         }       94          95         sumTotal=sumSingleNum+sumDoubleNum+sumSingleNumChild+sumSingleNum2Child; 96          97         //计算Luhm值 98         int k= sumTotal%10==0?10:sumTotal%10;         99         int luhm= 10-k;100         101         if(lastNum == luhm){102             return SUCCESS;//验证通过103         }104         else{105             return ILLEGAL_NUMBER;106         }      107     }108     109     public static void main(String[] args) {110         String bankno = "6214857110432079";111         System.out.println(bankno+":"+luhmCheck(bankno));112         String bankno1 = "6212164000046323291";113         System.out.println(bankno1+":"+luhmCheck(bankno1));114         String bankno2 = "6222023104004123546";115         System.out.println(bankno2+":"+luhmCheck(bankno2));116     }117 }