使用java代码做一个功能齐全的redis分布式锁

以下是一个基本的Redis分布式锁的Java实现。它包括获取锁、释放锁、自动续期、可重入等功能。可以根据具体需求进行修改和优化。

import redis.clients.jedis.Jedis;
import redis.clients.jedis.params.SetParams;

public class RedisDistributedLock {
    private final Jedis jedis;
    private final String lockKey;
    private final String lockValue;
    private final int expireTime;
    private final long retryInterval;
    private final int maxRetryTimes;
    private final ThreadLocal<Integer> reentrantCount;

    public RedisDistributedLock(Jedis jedis, String lockKey, String lockValue, int expireTime, long retryInterval, int maxRetryTimes) {
        this.jedis = jedis;
        this.lockKey = lockKey;
        this.lockValue = lockValue;
        this.expireTime = expireTime;
        this.retryInterval = retryInterval;
        this.maxRetryTimes = maxRetryTimes;
        this.reentrantCount = new ThreadLocal<>();
        this.reentrantCount.set(0);
    }

    /**
     * 获取锁
     *
     * @return true：获取锁成功；false：获取锁失败
     */
    public boolean lock() throws InterruptedException {
        int retryTimes = 0;
        while (retryTimes < maxRetryTimes) {
            SetParams params = new SetParams();
            params.nx().ex(expireTime);
            String result = jedis.set(lockKey, lockValue, params);
            if ("OK".equals(result)) {
                return true;
            }
            retryTimes++;
            Thread.sleep(retryInterval);
        }
        return false;
    }

    /**
     * 释放锁
     */
    public void unlock() {
        int count = reentrantCount.get();
        if (count > 0) {
            reentrantCount.set(count - 1);
            return;
        }
        if (lockValue.equals(jedis.get(lockKey))) {
            jedis.del(lockKey);
        }
    }

    /**
     * 自动续期
     */
    public void renew() {
        jedis.expire(lockKey, expireTime);
    }

    /**
     * 可重入锁
     *
     * @return true：获取锁成功；false：获取锁失败
     */
    public boolean reentrantLock() {
        int count = reentrantCount.get();
        if (count > 0) {
            reentrantCount.set(count + 1);
            return true;
        }
        if (lockValue.equals(jedis.get(lockKey))) {
            reentrantCount.set(1);
            return true;
        }
        return false;
    }
}

使用示例：

public class Main {
    public static void main(String[] args) throws InterruptedException {
        Jedis jedis = new Jedis("localhost", 6379);
        RedisDistributedLock lock = new RedisDistributedLock(jedis, "my_lock", "my_value", 10, 1000, 3);
        try {
            if (lock.lock()) {
                // 获取锁成功，执行业务逻辑
                System.out.println("Got the lock, do something...");
                Thread.sleep(5000);
            } else {
                // 获取锁失败，处理异常情况
                System.out.println("Failed to get the lock");
            }
        } finally {
            lock.unlock();
        }
    }
}

注意事项：

- RedisDistributedLock类的构造函数需要传入Jedis对象，因此需要先导入jedis依赖。
- 为了防止误删其他线程的锁，lockValue应该是一个随机生成的字符串，确保每个线程都有自己的标识。
- 自动续期和可重入锁需要在业务逻辑中显式调用，否则会因为过期或者重入次数不匹配而导致锁失效。