Redis分布式锁

ReturnLock returnLock = RedisLock.applyByIds(scIds, redisLockTime, organizationId, () -> {
    // dothing 具体的代码业务逻辑
    return 123;
});
 
if (!returnLock.getFlag()) {
    if(returnLock.getLock()){
        throw new CommonException("归集数据有程序正在运行，请稍候刷新页面重试");
    }else {
        throw new CommonException(returnLock.getErrorMsg());
    }
}
// 返回对象
System.out.println(returnLock.getResObj()) // 123

public static ReturnLock applyByIds(List<Long> scIds, Long timeOutToDeleteRedisKey, Long tenantId,
                                    Supplier<Object> supplier) {
    // 获得锁
    Map<String, String> keyMap = getLockByIds(scIds, timeOutToDeleteRedisKey, tenantId);
    ReturnLock returnLock = new ReturnLock();
    returnLock.setFlag(true);
    returnLock.setLock(false);
    try {
        // 判断主键ID数量和加锁的数量是否一致，不一致说明有加锁失败的数据，返回失败锁信息
        if(scIds.size() > keyMap.size()){
            returnLock.setFlag(false);
            returnLock.setLock(true);
            returnLock.setKeyMap(keyMap);
            return returnLock;
        }
        // 应用代码执行后的返回结果 supplier：java8四大内置函数的供给型接口
        // Supplier<T>（供给型接口）无参数，返回类型为T的对象：T get()
        returnLock.setResObj(supplier.get());
    }catch (Exception e) {
        returnLock.setFlag(false);
        returnLock.setErrorMsg(e.getMessage());
        e.printStackTrace();
    }finally {
        // 应用代码执行报错，解锁
        unLockByIds(keyMap);
    }
    return returnLock;
}

private static Map<String, String> getLockByIds(List<Long> scIds, Long timeOutToDeleteRedisKey, Long tenantId) {
    Map<String, String> keyMap = new HashMap<>();
    // 从spring上下文中获取Redis的操作对象，因为这个代码是写在util中，所以通过上下文方式获取bean对象
    // RedisHelper：Redis的操作对象，我们自己公司基于redisTemplate封装的
    RedisHelper redisHelper = SpringUtil.getBean(RedisHelper.class);
    try {
        if (CollectionUtil.isNotEmpty(scIds)) {
            for (int i = 0; i < scIds.size(); i++) {
                String item = "L_" + scIds.get(i);
                String UUID = UUIDUtils.generateTenantUUID(tenantId);
                // 判断key值是否被锁，如果没有锁则加锁并设置过期时间, 如果有锁, 则报错并立即释放已加的锁
                // strSetIfAbsent会返回true/false,底层是封装了java的setIfAbsent方法和Redis的setnx方法
                // 如果设置成功返回true否则false
                if (redisHelper.strSetIfAbsent(item, UUID)) {
                    // 设置过期时间
                    redisHelper.setExpire(item, timeOutToDeleteRedisKey, TimeUnit.SECONDS);
                    // 保存设置的锁信息
                    keyMap.put(item, UUID);
                } else {
                    // 锁设置异常，表示有数据被锁住了，解锁之间加锁的数据
                    if (MapUtil.isNotEmpty(keyMap)) {
                        if (unLockByIds(keyMap)) {
                            // 解锁失败再次解锁
                            unLockByIds(keyMap);
                        }
                    }
                    // 返回锁信息
                    return keyMap;
                }
            }
        }
        return keyMap;
    }catch (Exception e) {
        e.printStackTrace();
    }
}

private static Boolean unLockByIds(Map<String, String> keyMap) {
    RedisHelper redisHelper = SpringUtil.getBean(RedisHelper.class);
    try {
        if (MapUtil.isEmpty(keyMap)) {
            return false;
        }
        // 判断是否是自己的锁
        for (String key : keyMap.keySet()) {
            String uuid = keyMap.get(key);
            if (StringUtils.equals(uuid, redisHelper.strGet(key))) {
                // 封装了redisTemplate.delete(key);
                redisHelper.delKey(key);
            }
        return true;
    }catch (Exception e) {
        e.printStackTrace();
        return false;
    }
}