Java 实现统一社会信用代码有效性校验

import com.yf.utils.StringUtils;
import java.util.HashMap;
import java.util.Map;

/**
 * 统一社会信用代码有效性校验
 *
 * @author FengQing
 * @program ruoyi-vue-file
 * @description
 * @date 2023/09/11
 */
public class TyshxydmVerificationUtil {

    public final static String ISTYSHXYDM = "true";
    public final static String ERROR_TYSHXYDM = "统一社会信用代码有误，请核对后再输入！";
    public final static String ERROR_TYSHXYDM_MIN = "统一社会信用代码不足18位，请核对后再输入！";
    public final static String ERROR_TYSHXYDM_MAX = "统一社会信用代码大于18位，请核对后再输入！";
    public final static String ERROR_TYSHXYDM_EMPTY = "统一社会信用代码不能为空！";
    private static Map<String, Integer> datas = null;
    static int[] power = {1, 3, 9, 27, 19, 26, 16, 17, 20, 29, 25, 13, 8, 24, 10, 30, 28};
    // 社会统一信用代码不含（I、O、S、V、Z） 等字母
    static char[] code = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'T', 'U', 'W', 'X', 'Y'};

    static {
        datas = new HashMap<>();
        for (int i = 0; i < code.length; i++) {
            datas.put(code[i] + "", i);
        }
    }

    /**
     * 判断是否是一个有效的统一社会信用代码
     *
     * @param tyshxydm
     * @return
     */
    public static String isTyshxydm(String tyshxydm) {
        if (StringUtils.isEmpty(tyshxydm) || StringUtils.isEmpty(tyshxydm.trim())) {
            return ERROR_TYSHXYDM_EMPTY;
        } else if (tyshxydm.trim().length() < 18) {
            return ERROR_TYSHXYDM_MIN;
        } else if (tyshxydm.trim().length() > 18) {
            return ERROR_TYSHXYDM_MAX;
        } else if (tyshxydm.equals("000000000000000000")) {
            return ERROR_TYSHXYDM;
        } else if (tyshxydm.startsWith("2")) {
            return ERROR_TYSHXYDM;
        } else {
            tyshxydm = tyshxydm.trim();
            String checkCharResult = checkChar(tyshxydm); // 校验字符合法性
            if (!StringUtils.isEmpty(checkCharResult)) {
                return checkCharResult;
            }
            int sum = sum(tyshxydm.substring(0, 17).toCharArray());
            int temp = sum % 31;
            temp = temp == 0 ? 31 : temp;
            return tyshxydm.substring(17, 18).equals(code[31 - temp] + "") ? ISTYSHXYDM : ERROR_TYSHXYDM;
        }
    }

    private static String checkChar(String tyshxydm) {
        String result = StringUtils.EMPTY;
        char[] chars = tyshxydm.toCharArray();
        for (int i = 0; i < chars.length; i++) {
            if (Character.isSpaceChar(chars[i]) || !datas.containsKey(chars[i] + "")) {
                result = ERROR_TYSHXYDM;
                break;
            }
        }
        return result;
    }

    /**
     * 加权计算
     *
     * @param chars
     * @return
     */
    private static int sum(char[] chars) {
        int sum = 0;
        for (int i = 0; i < chars.length; i++) {
            int code = datas.get(chars[i] + "");
            sum += power[i] * code;
        }
        return sum;

    }
}