import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * @description: Redis分布式鎖實現(xiàn)工具類
 * @author: qianghaohao
 * @time: 2021/7/19
 */
@Component
public class RedisLock {
    @Autowired
    StringRedisTemplate redisTemplate;

    /**
     * 獲取鎖
     *
     * @param lockKey    鎖
     * @param identity   身份標識（保證鎖不會被其他人釋放）
     * @param expireTime 鎖的過期時間（單位：秒）
     * @return
     */
    public boolean lock(String lockKey, String identity, long expireTime) {
        // 由于我們目前 springboot 版本比較低，1.5.9，因此還不支持下面這種寫法
        // return redisTemplate.opsForValue().setIfAbsent(lockKey, identity, expireTime, TimeUnit.SECONDS);
        if (redisTemplate.opsForValue().setIfAbsent(lockKey, identity)) {
            redisTemplate.expire(lockKey, expireTime, TimeUnit.SECONDS);
            return true;
        }
        return false;
    }

    /**
     * 釋放鎖
     *
     * @param lockKey  鎖
     * @param identity 身份標識（保證鎖不會被其他人釋放）
     * @return
     */
    public boolean releaseLock(String lockKey, String identity) {
        String luaScript = "if " +
                "  redis.call('get', KEYS[1]) == ARGV[1] " +
                "then " +
                "  return redis.call('del', KEYS[1]) " +
                "else " +
                "  return 0 " +
                "end";
        DefaultRedisScript<Boolean> redisScript = new DefaultRedisScript<>();
        redisScript.setResultType(Boolean.class);
        redisScript.setScriptText(luaScript);
        List<String> keys = new ArrayList<>();
        keys.add(lockKey);
        Object result = redisTemplate.execute(redisScript, keys, identity);
        return (boolean) result;
    }
}

@Autowired
private RedisLock redisLock;  // redis 分布式鎖

        String redisLockKey = String.format("%s:docker-image:%s", REDIS_LOCK_PREFIX, imageVo.getImageRepository());
        String redisLockValue = UUID.randomUUID().toString();
        try {
            if (!redisLock.lock(redisLockKey, redisLockValue, REDIS_LOCK_TIMEOUT)) {
                logger.info("redisLockKey [" + redisLockKey + "] 已存在，不執(zhí)行鏡像插入和更新");
                result.setMessage("新建鏡像頻繁，稍后重試，鎖占用");
                return result;
            }
            ... // 執(zhí)行業(yè)務(wù)邏輯
       catch (Execpion e) {
            ... // 異常處理
       } finally {  // 釋放鎖
            if (!redisLock.releaseLock(redisLockKey, redisLockValue)) {
                logger.error("釋放redis鎖 [" + redisLockKey + "] 失敗);
            } else {
                logger.error("釋放redis鎖 [" + redisLockKey + "] 成功");
            }
        }