设计一个简单的 RedisDistributedLock 类，实现单例模式，并包含基本的锁定机制。这个类将使用 Redis 来管理锁，确保在分布式系统中资源的同步访问

import redis.clients.jedis.Jedis;public class RedisDistributedLock {private static RedisDistributedLock instance;private Jedis jedis;private final String redisHost;private final int redisPort;// 私有构造函数，防止外部实例化private RedisDistributedLock(String host, int port) {this.redisHost = host;this.redisPort = port;this.jedis = new Jedis(redisHost, redisPort);}// 公共静态方法，返回唯一实例public static synchronized RedisDistributedLock getSingletonInstance(String host, int port) {if (instance == null) {instance = new RedisDistributedLock(host, port);}return instance;}// 尝试获取锁public boolean lockTransaction(String transactionId) {String key = "lock:" + transactionId;String result = jedis.set(key, "locked", "NX", "EX", 10); // 锁超时时间为10秒return "OK".equals(result);}// 释放锁public void unlockTransaction(String transactionId) {String key = "lock:" + transactionId;jedis.del(key);}// 清理资源public void close() {jedis.close();}
}