Client 接口

public interface LiveTecherClient {
    /**
     * 获取直播老师信息
     *
     * @param id    直播老师id
     * @return 老师信息
     */
    LiveTeacherInfo getTeacher(long id);

    /**
     * 批量获取直播老师信息
     *
     * @param ids 直播老师id 列表
     * @return 直播老师id to LiveTeacherInfo
     */
    Map<Long, LiveTeacherInfo> getIdToTeacher(List<Long> ids);

    /**
     * admin 用户是否是直播老师
     *
     * @param adminName admin 用户名称
     * @return true: admin 用户是直播老师
     */
    boolean isTeacher(String adminName);
}

涉及的数据结构：

@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class LiveTeacherInfo {
    private long id; // 直播老师 ID
    private String nickName; // 直播老师 名称
    private String adminName; // 老师的 admin 帐号用户名
}

Fake Client 实现

public class FakeLiveTecherClient implements LiveTecherClient {
    private volatile AtomicLong idGen = new AtomicLong();
    private volatile List<LiveTeacherInfo> liveTeacherInfos = new CopyOnWriteArrayList<>();

    public LiveTeacherInfo createLiveTeacher() {
        return createLiveTeacher("adminName");
    }

    public LiveTeacherInfo createLiveTeacher(String adminName) {
        LiveTeacherInfo liveTeacherInfo = LiveTeacherInfo.builder()
            .id(idGen.incrementAndGet())
            .nickName("Colin")
            .adminName(adminName)
            .build();
        liveTeacherInfos.add(liveTeacherInfo);
        return liveTeacherInfo;
    }

    @Override
    public LiveTeacherInfo getTeacher(long id) {
        return liveTeacherInfos.stream()
            .filter(v -> v.getId() == id)
            .findFirst()
            .orElse(null);
    }

    @Override
    public Map<Long, LiveTeacherInfo> getIdToTeacher(List<Long> ids) {
        return liveTeacherInfos.stream()
            .filter(v -> ids.contains(v.getId()))
            .collect(Collectors.toMap(LiveTeacherInfo::getId, Function.identity()));
    }

    @Override
    public boolean isTeacher(String adminName) {
        return liveTeacherInfos.stream()
            .anyMatch(v -> v.getAdminName().equals(adminName));
    }
}