package src.java8.bitwise;

/**
 * @author shi.likun
 * @create 2021-01-06 14:59
 */
public class Permission {
    /**是否允许查询 二进制第一位，0 否 1是*/
    public static final int ALLOW_SELECT = 1<<0; //0001 = 1

    /**是否允许新增 二进制第二位，0 否 1是*/
    public static final int ALLOW_INSERT = 1<<1;//0010 = 2

    /**是否允许修改 二进制第三位，0 否 1是*/
    public static final int ALLOW_UPDATE = 1<<2;//0100 = 4

    /**是否允许删除 二进制第四位，0 否 1是*/
    public static final int ALLOW_DELETE = 1<<3;//1000 = 8

    /**存储目前的状态*/
    private int flag;

    /**设置用户权限*/
    public void setPer(int per){
        flag = per;
    }

    /**增加用户权限（1个或者多个）*/
    public void enable(int per){
        flag = flag|per;
    }

    /**删除用户权限（1个或者多个）*/
    public void disable(int per){
        flag = flag&~per;
    }

    /**判断用户的权限*/
    public boolean isAllow(int per){
        return ((flag&per) == per);
    }

    /**判断用户没有的权限*/
    public boolean isNotAllow(int per){
        return ((flag&per) == 0);
    }

    public static void main(String[] args) {
        int flag = 15;//二进制1111，拥有所有权限
        Permission permission = new Permission();
        permission.setPer(flag);
        permission.disable(ALLOW_DELETE|ALLOW_INSERT);
        System.out.println("select = " + permission.isAllow(ALLOW_SELECT));
        System.out.println("update = " + permission.isAllow(ALLOW_UPDATE));
        System.out.println("insert = " + permission.isAllow(ALLOW_INSERT));
        System.out.println("delete = " + permission.isAllow(ALLOW_DELETE));
    }
}