Redis的SETNX命令的簡單分布式鎖實現的Java示例

首先，確保你已經引入了Jedis這個Java Redis客戶端庫。你可以通過Maven或Gradle來添加依賴。

1、Maven依賴

<dependency><groupId>redis.clients</groupId><artifactId>jedis</artifactId><version>3.7.0</version>
</dependency>

2、Java代碼示例

import redis.clients.jedis.Jedis;
import java.util.UUID;
import java.util.concurrent.TimeUnit;public class RedisDistributedLock {private static final String LOCK_SUCCESS = "OK";private static final String SET_IF_NOT_EXIST = "NX";private static final String SET_WITH_EXPIRE_TIME = "PX";private static final Long RELEASE_SUCCESS = 1L;/*** 嘗試獲取分布式鎖* @param jedis Redis客戶端* @param lockKey 鎖* @param requestId 請求標識* @param expireTime 超期時間* @return 是否獲取成功*/public static boolean tryGetDistributedLock(Jedis jedis, String lockKey, String requestId, int expireTime) {String result = jedis.set(lockKey, requestId, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, expireTime);return LOCK_SUCCESS.equals(result);}/*** 釋放分布式鎖* @param jedis Redis客戶端* @param lockKey 鎖* @param requestId 請求標識* @return 是否釋放成功*/public static boolean releaseDistributedLock(Jedis jedis, String lockKey, String requestId) {String script = "if redis.call('get', KEYS[1]) == ARGV[1] then " +"return redis.call('del', KEYS[1]) " +"else " +"return 0 " +"end";Object result = jedis.eval(script, Collections.singletonList(lockKey), Collections.singletonList(requestId));return RELEASE_SUCCESS.equals(result);}public static void main(String[] args) {Jedis jedis = new Jedis("localhost", 6379);String lockKey = "myLock";String requestId = UUID.randomUUID().toString();int expireTime = 10 * 1000;try {if (tryGetDistributedLock(jedis, lockKey, requestId, expireTime)) {try {// 獲取到鎖，執(zhí)行業(yè)務邏輯System.out.println("執(zhí)行業(yè)務邏輯...");TimeUnit.SECONDS.sleep(5);} finally {releaseDistributedLock(jedis, lockKey, requestId);}} else {// 沒有獲取到鎖，執(zhí)行其他邏輯System.out.println("未獲取到鎖，執(zhí)行其他邏輯...");}} finally {if (jedis != null) {jedis.close();}}}
}

上述代碼中，tryGetDistributedLock方法用于嘗試獲取分布式鎖。它使用Redis的SET命令來實現，并通過NX和PX選項來確保只有在鎖不存在時設置鎖，并設置鎖的過期時間。
releaseDistributedLock方法用于釋放分布式鎖，它使用Redis的Lua腳本來確保只有鎖的持有者才能釋放鎖。