Redis中Redlock算法的具体使用

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>4.0.1</version>
</dependency>

import redis.clients.jedis.Jedis;
import java.util.List;
import java.util.UUID;

public class RedisRedlock {
    private List<Jedis> redisClients;
    private int retryDelayMillis = 200;
    private int expireMillis = 30000;
    private int quorum;  // 大多数实例数量

    public RedisRedlock(List<Jedis> redisClients) {
        this.redisClients = redisClients;
        this.quorum = (redisClients.size() / 2) + 1;
    }

    public String acquireLock(String lockKey) {
        String lockValue = UUID.randomUUID().toString();
        long startMillis = System.currentTimeMillis();
        int retryCount = 3;

        while (retryCount-- > 0) {
            int lockedCount = 0;
            long elapsedMillis = 0;

            for (Jedis client : redisClients) {
                if (client.set(lockKey, lockValue, "NX", "PX", expireMillis) != null) {
                    lockedCount++;
                }
            }

            elapsedMillis = System.currentTimeMillis() - startMillis;

            if (lockedCount >= quorum && elapsedMillis < expireMillis) {
                return lockValue;
            } else {
                for (Jedis client : redisClients) {
                    if (lockValue.equals(client.get(lockKey))) {
                        client.del(lockKey);
                    }
                }
            }

            try {
                Thread.sleep(retryDelayMillis);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }

        return null;
    }

    public boolean releaseLock(String lockKey, String lockValue) {
        boolean isReleased = false;
        for (Jedis client : redisClients) {
            String luaScript = "if redis.call('get', KEYS[1]) == ARGV[1] then " +
                               "return redis.call('del', KEYS[1]) else return 0 end";
            Object result = client.eval(luaScript, 1, lockKey, lockValue);
            if (result.equals(1L)) {
                isReleased = true;
            }
        }
        return isReleased;
    }
}

import redis.clients.jedis.Jedis;
import java.util.Arrays;

public class TestRedlock {
    public static void main(String[] args) {
        Jedis redis1 = new Jedis("localhost", 6379);
        Jedis redis2 = new Jedis("localhost", 6380);
        Jedis redis3 = new Jedis("localhost", 6381);

        RedisRedlock redlock = new RedisRedlock(Arrays.asList(redis1, redis2, redis3));
        String lockKey = "my_distributed_lock";
        String lockValue = redlock.acquireLock(lockKey);

        if (lockValue != null) {
            try {
                System.out.println("Lock acquired, performing critical operations.");
                // 执行需要同步的操作
            } finally {
                redlock.releaseLock(lockKey, lockValue);
                System.out.println("Lock released.");
            }
        } else {
            System.out.println("Failed to acquire lock.");
        }

        redis1.close();
        redis2.close();
        redis3.close();
    }
}