根据角色动态展示

要求，使用redis缓存，根据用户角色可以动态展示菜单

1， mapper层

接口

 public interface MenuMapper {
    //根据角色id查询一级菜单
    List<Menu> selectFirstLevelMenus(Integer roleId);
   //根据一级菜单Id查询二级菜单
   List<Menu> selectSecondLevelMenus(Integer id);
}

xml映射文件

<select id="selectFirstLevelMenus" resultType="Menu">
    select id, m.name, path, icon
    from t_menu m,
         t_role_menu rm
    where m.id = rm.menu_id
      and rm.role_id = #{roleid}
      and level = 1
    ORDER BY priority

</select>

<select id="selectSecondLevelMenus" resultType="Menu">
    select  name,linkurl ,path from   t_menu  where parentMenuId=#{id}
</select>

2 ，实现登录的userserImpl中存权限或者角色之前，根据角色id得到一级菜单继而得到二级菜单，并且存入redisd的List中

@Service
@Transactional
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Autowired
    private RoleMapper roleMapper;
    @Autowired
    private PermissionMapper permissionMapper;
    @Autowired
    private RedisTemplate redisTemplate;
    @Autowired
    private MenuMapper menuMapper;

    @Override
    public User findByUsername(String username) {
        User user = userMapper.selectByUsername(username);
        if (null != user) {
            Set<Role> roles = roleMapper.selectByUserid(user.getId());
            if (roles != null && roles.size() > 0) {

                for (Role role : roles) {

                    //用List类型缓存一级菜单,key就是角色的keyword
                    BoundListOperations opt = redisTemplate.boundListOps(role.getKeyword());
                    Set<Permission> permissions = permissionMapper.selectByRoleid(role.getId());
                    if (permissions != null && permissions.size() > 0) {
                        role.setPermissions(permissions);
                    }
                    List range = opt.range(0, -1);
                    if (null == range || range.size() == 0) {
                        //查询角色对应的一级菜单
                        List<Menu> firstLevelMenus = menuMapper.selectFirstLevelMenus(role.getId());
                        for (Menu menu : firstLevelMenus) {
                            //查询二级菜单
                            List<Menu> secondLevelMenus = menuMapper.selectSecondLevelMenus(menu.getId());
                            //设置一级菜单的子菜单
                            menu.setChildren(secondLevelMenus);
                            //存一级菜单到redis
                            opt.rightPush(menu);
                        }
                        //设置一天有效
                        opt.expire(24, TimeUnit.HOURS);
                    }
                }
                user.setRoles(roles);
            }
        }
        return user;
    }
}

3，main页面

//发请求，获取用户的菜单
axios.get('../user/getMenus').then(response => {
   this.menuList=response.data.data;
});

4，controller 中得到认证实体，然后获取其中的角色——以“"ROLE_"开头，

    @Autowired
    private RedisTemplate redisTemplate;

    @ApiOperation("获取用户的菜单")
    @GetMapping("/getMenus")
    public Result getMenus() {
        User user = (User) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
        //得到一个集合,默认当前的getAuthorities()返回结合中有角色也有权限
        Stream<GrantedAuthority> stream = user.getAuthorities().stream();
        List<String> role_keywords = stream.filter(t -> t.getAuthority().startsWith("ROLE_")).map(e -> e.getAuthority()).collect(Collectors.toList());
        //角色的keyword
        String s = role_keywords.get(0);
        BoundListOperations opt = redisTemplate.boundListOps(s);
        //一级菜单
        List<Menu> ranges = opt.range(0, -1);
        //调用MenuSerice中的方法根据一级菜单获取对应的二级菜单
        //Map<String, Object> map = new HashMap<>();
        return new Result(true, "一级菜单获取成功", ranges);
    }
}