算法:
W[] = 7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2
∑(a[i]×W[i])(mod 11)
校驗位:1 0 X 9 8 7 6 5 4 3 2
舉個栗子:
身份證號:102154198801238569
a[] = 10215419880123856
身份證每一位和W[]每一位相乘後求和,模除以11,取校驗位相應的位數即可
代碼
package utils;
import java.text.ParseException;
import java.text.SimpleDateFormat;
/**
* Created by lwg
*/
public class BankUtils {
/**
* 校驗身份證號
*
* @param idCardNo 身份證號
* @return true通過,false未通過
*/
public static boolean checkIdCardNo(String idCardNo) {
if (null == idCardNo) {
return false;
}
idCardNo = idCardNo.toLowerCase();
if (null == idCardNo || (idCardNo.length() != 18 && idCardNo.length() != 15)) {
return false;
}
String[] RC = {"1", "0", "x", "9", "8", "7", "6", "5", "4", "3", "2"};
boolean checkBirthday;
String birthday;
try {
if (idCardNo.length() == 18) {// 18位
birthday = idCardNo.substring(6, 14);
checkBirthday = isDate(birthday, "yyyyMMdd");
int[] W = {7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2};
int sum = 0;
for (int i = 0; i < idCardNo.length() - 1; i++) {
int c = Integer.parseInt(idCardNo.substring(i, i + 1));
sum += W[i] * c;
}
int r = sum % 11;
if (RC[r].equals(idCardNo.substring(17)) && checkBirthday) {
return true;
} else {
return false;
}
} else {//15位
birthday = "19" + idCardNo.substring(6, 12);
checkBirthday = isDate(birthday, "yyyyMMdd");
if (checkBirthday) {
return true;
} else {
return false;
}
}
} catch (NumberFormatException e) {
e.printStackTrace();
return false;
}
}
/**
* 是否爲合法日期
*
* @param dateString 日期
* @param format 指定日期格式爲四位年/兩位月份/兩位日期,注意yyyy/MM/dd區分大小寫;
* @return
*/
public static boolean isDate(String dateString, String format) {
boolean convertSuccess = true;
// 指定日期格式爲四位年/兩位月份/兩位日期,注意yyyy/MM/dd區分大小寫;
SimpleDateFormat smf = new SimpleDateFormat(format);
try {
// 設置lenient爲false. 否則SimpleDateFormat會比較寬鬆地驗證日期,比如2007/02/29會被接受,並轉換成2007/03/01
smf.setLenient(false);
smf.parse(dateString);
} catch (ParseException e) {
//e.printStackTrace();
//如果throw java.text.ParseException或者NullPointerException,就說明格式不對
convertSuccess = false;
}
return convertSuccess;
}
}
原文鏈接:通過身份證校驗位檢驗身份證正確性