加锁使用命令：set lock_key unique_value NX PX 1000

NX:等同于SETNX ，只有键不存在时才能设置成功

PX：设置键的过期时间为10秒

unique_value：一个必须是唯一的随机值（UUID），通常由客户端生成。解决误删他人锁的关键。

这条命令是原子性的，要么一起成功，要么一起失败。

解锁：Lua 脚本保证原子性

需要先判断当前锁的值是否是自己设置的unique_value，如果是，才能使用DEL删除，两个操作必须保证原子性，使用Lua脚本安全的释放锁；

// unlock.lua

if redis.call("get", KEYS[1]) == ARGV[1] then

return redis.call("del", KEYS[1])

else

return 0

end

下面是一个完整的基于 Spring Boot 和 Vue 的秒杀案例，使用 Redis 分布式锁防止超卖。

后端实现 (Spring Boot)

1. 添加依赖 (pom.xml)

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-pool2</artifactId></dependency>
</dependencies>

2. 应用配置 (application.yml)

spring:redis:host: localhostport: 6379password: database: 0lettuce:pool:max-active: 8max-wait: -1msmax-idle: 8min-idle: 0
server:port: 8080

3. Redis 分布式锁工具类

@Component
public class RedisDistributedLock {@Autowiredprivate StringRedisTemplate redisTemplate;// 锁的超时时间，防止死锁private static final long LOCK_EXPIRE = 30000L; // 30秒// 获取锁的等待时间private static final long LOCK_WAIT_TIME = 3000L; // 3秒// 锁的重试间隔private static final long SLEEP_TIME = 100L; // 100毫秒/*** 尝试获取分布式锁* @param lockKey 锁的key* @param requestId 请求标识（可以使用UUID）* @param expireTime 锁的超时时间(毫秒)* @return 是否获取成功*/public boolean tryLock(String lockKey, String requestId, long expireTime) {try {long startTime = System.currentTimeMillis();while (true) {// 使用SET命令代替SETNX，保证原子性Boolean result = redisTemplate.opsForValue().setIfAbsent(lockKey, requestId, expireTime, TimeUnit.MILLISECONDS);if (Boolean.TRUE.equals(result)) {return true; // 获取锁成功}// 检查是否超时if (System.currentTimeMillis() - startTime > LOCK_WAIT_TIME) {return false; // 获取锁超时}// 等待一段时间后重试try {Thread.sleep(SLEEP_TIME);} catch (InterruptedException e) {Thread.currentThread().interrupt();return false;}}} catch (Exception e) {return false;}}/*** 释放分布式锁* @param lockKey 锁的key* @param requestId 请求标识* @return 是否释放成功*/public boolean releaseLock(String lockKey, String requestId) {// 使用Lua脚本保证原子性 ，先判断锁的键值是否等于requestId，等于才能进行删除String script = "if redis.call('get', KEYS[1]) == ARGV[1] then " +"return redis.call('del', KEYS[1]) " +"else " +"return 0 " +"end";DefaultRedisScript<Long> redisScript = new DefaultRedisScript<>();redisScript.setScriptText(script);redisScript.setResultType(Long.class);Long result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey), requestId);return result != null && result == 1;}/*** 简化版获取锁（使用默认超时时间）*/public boolean tryLock(String lockKey, String requestId) {return tryLock(lockKey, requestId, LOCK_EXPIRE);}
}

4. 商品服务类

@Service
public class ProductService {@Autowiredprivate RedisDistributedLock redisDistributedLock;@Autowiredprivate StringRedisTemplate redisTemplate;private static final String PRODUCT_STOCK_PREFIX = "product:stock:";private static final String PRODUCT_LOCK_PREFIX = "product:lock:";/*** 初始化商品库存  //从数据库中查询出对应商品的库存数量*/public void initProductStock(Long productId, Integer stock) {redisTemplate.opsForValue().set(PRODUCT_STOCK_PREFIX + productId, stock.toString());}/*** 获取商品库存*/public Integer getProductStock(Long productId) {String stockStr = redisTemplate.opsForValue().get(PRODUCT_STOCK_PREFIX + productId);return stockStr != null ? Integer.parseInt(stockStr) : 0;}/*** 秒杀下单（使用分布式锁）*/public boolean seckillProduct(Long productId, String userId) {String lockKey = PRODUCT_LOCK_PREFIX + productId;String requestId = UUID.randomUUID().toString();try {// 尝试获取锁if (!redisDistributedLock.tryLock(lockKey, requestId)) {return false; // 获取锁失败}// 检查库存Integer stock = getProductStock(productId);if (stock <= 0) {return false; // 库存不足}// 模拟业务处理耗时  //修改商品的库存try {Thread.sleep(100);} catch (InterruptedException e) {Thread.currentThread().interrupt();}// 扣减库存redisTemplate.opsForValue().decrement(PRODUCT_STOCK_PREFIX + productId);// 记录订单（这里简化处理，实际应保存到数据库）System.out.println("用户 " + userId + " 成功秒杀商品 " + productId);return true;} finally {// 释放锁redisDistributedLock.releaseLock(lockKey, requestId);}}
}

前端实现 (Vue)

1. 安装依赖

npm install axios

2. 秒杀页面组件 (Seckill.vue)

<template><div class="seckill-container"><h1>商品秒杀</h1><div class="product-info"><h2>商品ID: {{ productId }}</h2><p>当前库存: {{ stock }}</p><button @click="initStock">初始化库存(100件)</button></div><div class="seckill-form"><input v-model="userId" placeholder="请输入用户ID" /><button @click="seckill" :disabled="isSeckilling">{{ isSeckilling ? '秒杀中...' : '立即秒杀' }}</button></div><div class="result"><h3>秒杀结果:</h3><p>{{ resultMessage }}</p></div><div class="logs"><h3>操作日志:</h3><ul><li v-for="(log, index) in logs" :key="index">{{ log }}</li></ul></div></div>
</template><script>
import axios from 'axios';export default {name: 'Seckill',data() {return {productId: 1001, // 商品IDstock: 0, // 当前库存userId: '', // 用户IDresultMessage: '', // 秒杀结果logs: [], // 操作日志isSeckilling: false // 是否正在秒杀};},mounted() {this.getStock();},methods: {// 获取商品库存async getStock() {try {const response = await axios.get(`http://localhost:8080/api/seckill/stock/${this.productId}`);this.stock = response.data;this.addLog(`获取库存成功: ${this.stock}`);} catch (error) {this.addLog('获取库存失败: ' + error.message);}},// 初始化库存async initStock() {try {await axios.post(`http://localhost:8080/api/seckill/init/${this.productId}/100`);this.addLog('初始化库存成功');this.getStock(); // 重新获取库存} catch (error) {this.addLog('初始化库存失败: ' + error.message);}},// 执行秒杀async seckill() {if (!this.userId) {this.resultMessage = '请输入用户ID';return;}this.isSeckilling = true;this.resultMessage = '秒杀中...';try {const response = await axios.post(`http://localhost:8080/api/seckill/${this.productId}?userId=${this.userId}`);this.resultMessage = response.data;this.addLog(`用户 ${this.userId} ${response.data}`);} catch (error) {this.resultMessage = '秒杀失败: ' + (error.response?.data || error.message);this.addLog(`用户 ${this.userId} 秒杀失败: ${error.response?.data || error.message}`);} finally {this.isSeckilling = false;this.getStock(); // 重新获取库存}},// 添加日志addLog(message) {const timestamp = new Date().toLocaleTimeString();this.logs.unshift(`[${timestamp}] ${message}`);// 只保留最近20条日志if (this.logs.length > 20) {this.logs.pop();}}}
};
</script><style scoped>
.seckill-container {max-width: 600px;margin: 0 auto;padding: 20px;
}.product-info, .seckill-form, .result, .logs {margin-bottom: 20px;padding: 15px;border: 1px solid #ddd;border-radius: 5px;
}input {padding: 8px;margin-right: 10px;width: 200px;
}button {padding: 8px 16px;background-color: #4CAF50;color: white;border: none;border-radius: 4px;cursor: pointer;
}button:disabled {background-color: #cccccc;cursor: not-allowed;
}button:hover:not(:disabled) {background-color: #45a049;
}ul {list-style-type: none;padding: 0;max-height: 300px;overflow-y: auto;
}li {padding: 5px 0;border-bottom: 1px solid #eee;
}
</style>

3. 主应用文件 (App.vue)

<template><div id="app"><Seckill /></div>
</template><script>
import Seckill from './components/Seckill.vue'export default {name: 'App',components: {Seckill}
}
</script><style>
#app {font-family: Avenir, Helvetica, Arial, sans-serif;-webkit-font-smoothing: antialiased;-moz-osx-font-smoothing: grayscale;color: #2c3e50;margin-top: 20px;
}
</style>