## 例1：判斷用戶是否開啟了密碼認(rèn)證--1 (滿足條件時(shí)返回查詢結(jié)果，沒有滿足條件時(shí)返回為空)
Select * from user where auth_method & 1;

## 例2：判斷用戶是否開啟了密碼認(rèn)證 + 短信認(rèn)證 (1+2)
Select * from user where auth_method & 3;

## 例2：判斷用戶是否開啟了密碼認(rèn)證 + 短信認(rèn)證 + 掃碼認(rèn)證 (1+2+4)
Select * from user where auth_method & 7;

import com.google.common.collect.Lists;
import lombok.Getter;
import org.springframework.util.CollectionUtils;

import java.util.Arrays;
import java.util.List;

@Getter
public enum AuthMethodEnum {

    PASSWORD(1, "密碼認(rèn)證"),
    SMS(2, "短信認(rèn)證"),
    QR_CODE(4, "掃碼認(rèn)證");

    private Integer method;

    private String name;

    AuthMethodEnum(Integer method, String name) {
        this.method = method;
        this.name = name;
    }

    /**
     * 將mysql存儲(chǔ)值解析成多種認(rèn)證方式
     * @param method
     * @return
     */
    public static List<Integer> parseAuthMethod(Integer method) {
        List<Integer> list = Lists.newArrayList();
        if (null == method) {
            return list;
        }
        AuthMethodEnum[] arr = AuthMethodEnum.values();
        // 需要先將method從大到小排序
        Arrays.sort(arr, (o1, o2) -> {
            if (o1.method > o2.method) {
                return -1;
            } else {
                return 0;
            }
        });
        for (AuthMethodEnum e : arr) {
            if (method >= e.method) {
                list.add(e.method);
                method = method - e.method;
            }
        }
        return list;
    }

    /**
     * 將任意種認(rèn)證方式計(jì)算后得到存儲(chǔ)值
     * @param methods
     * @return
     */
    public static Integer calculateAuthMethod(List<Integer> methods) {
        if (CollectionUtils.isEmpty(methods)) {
            return 0;
        }
        return methods.stream().mapToInt(p -> p).sum();
    }

    public static void main(String[] args) {
        System.out.println(parseAuthMethod(8));
    }
}