// JavaScript示例代码
   const debounceSearch = _.debounce((query) => {
       fetch(`/api/search?q=${query}`)
           .then(response => response.json()
           .then(data => console.log(data);
   }, 300);

   document.getElementById('search-input').addEventListener('input', (e) => {
       debounceSearch(e.target.value);
   });
   

   // JavaScript示例代码
   const throttleScroll = _.throttle(() => {
       console.log('Scrolled');
   }, 1000);

   window.addEventListener('scroll', throttleScroll);
   

   <!-- HTML 示例代码 -->
   <button id="submit-btn" type="submit">提交</button>

   // JavaScript 示例代码
   document.getElementById('submit-btn').addEventListener('click', async (e) => {
       e.preventDefault();
       const button = e.target;
       button.disabled = true;
       button.textContent = '提交中...';

       try {
           await fetch('/api/submit', {
               method: 'POST',
               body: JSON.stringify(formData)
           });
           alert('提交成功');
       } catch (error) {
           console.error('提交失败:', error);
           alert('提交失败，请重试');
       } finally {
           button.disabled = false;
           button.textContent = '提交';
       }
   });

   // Java示例代码
   String requestId = UUID.randomUUID().toString();
   // 将requestId保存到数据库或缓存中...

// JavaScript示例代码
fetch('/api/resource', {
  method: 'PUT',
  headers: {
    'If-Match': '"current-version-number"' // 传入版本号
  },
  body: JSON.stringify(data)
})

   // Java示例代码
   String token = Jwts.builder()
       .setSubject(user.getId().toString()
       .setExpiration(new Date(System.currentTimeMillis() + 3600000)
       .signWith(SignatureAlgorithm.HS512, secretKey)
       .compact();
   

   // Java示例代码
   long currentTimeMillis = System.currentTimeMillis();
   // 比较currentTimeMillis与传入的时间戳...
   

-- SQL示例代码
BEGIN;
SELECT * FROM orders WHERE order_id = ? FOR UPDATE;
-- 执行业务逻辑...
COMMIT;

// Java示例代码
int rowsAffected = jdbcTemplate.update(
    "UPDATE orders SET status = ?, version = version + 1 WHERE order_id = ? AND version = ?",
    newStatus, orderId, currentVersion
);
if (rowsAffected == 0) {
    throw new OptimisticLockException("Data has been modified by another transaction.");
}

// Redis分布式锁示例代码
String lockKey = "order_lock_" + orderId;
String lockValue = UUID.randomUUID().toString();
Boolean isLocked = redisTemplate.opsForValue().setIfAbsent(lockKey, lockValue, 10, TimeUnit.SECONDS);
if (isLocked != null && isLocked) {
    try {
        // 执行业务逻辑...
    } finally {
        if (lockValue.equals(redisTemplate.opsForValue().get(lockKey)) {
            redisTemplate.delete(lockKey);
        }
    }
} else {
    // 处理无法获取锁的情况...
}

import redis
import uuid
r = redis.Redis(host='localhost', port=6379, db=0)
lock_key = "my_lock"
unique_value = uuid.uuid4()
lock_acquired = r.setnx(lock_key, unique_value)
if lock_acquired:
    print("Lock acquired successfully")
else:
    print("Failed to acquire lock")

WATCH lock_key
GET lock_key
if value == unique_value
    MULTI
    DEL lock_key
    EXEC
else
    UNWATCH

def release_lock(redis_conn, lock_key, unique_value):
    value = redis_conn.get(lock_key)
    if value == unique_value:
        redis_conn.delete(lock_key)
        print("Lock released successfully")
    else:
        print("Cannot release a lock not held by this client")

lock_acquired = r.set(lock_key, unique_value, px = 30000)

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
CuratorFramework client = CuratorFrameworkFactory.newClient("zookeeper_server:2181", new ExponentialBackoffRetry(1000, 3);
client.start();
InterProcessMutex lock = new InterProcessMutex(client, "/locks/my_lock");
try {
    if (lock.acquire(10, TimeUnit.SECONDS) {
        System.out.println("Lock acquired successfully");
        // 执行幂等性相关操作
    } else {
        System.out.println("Failed to acquire lock");
    }
} catch (Exception e) {
    e.printStackTrace();
}

try {
    lock.release();
    System.out.println("Lock released successfully");
} catch (Exception e) {
    e.printStackTrace();
}

     // Java示例代码
     RLock lock = redissonClient.getLock("order_lock_" + orderId);
     try {
         if (lock.tryLock(10, TimeUnit.SECONDS) {
             // 执行业务逻辑...
         }
     } catch (InterruptedException e) {
         Thread.currentThread().interrupt();
     } finally {
         lock.unlock();
     }
     

     -- 创建订单表时添加唯一索引
     CREATE TABLE orders (
       id BIGINT AUTO_INCREMENT PRIMARY KEY,
       order_id VARCHAR(50) NOT NULL UNIQUE,
       status VARCHAR(20),
       version INT DEFAULT 0,
       created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
     );
     

// Java示例代码
String orderId = UUID.randomUUID().toString();
RLock lock = redissonClient.getLock("order_lock_" + orderId);

try {
    if (lock.tryLock(10, TimeUnit.SECONDS) {
        try {
            // 尝试插入订单记录
            int rowsAffected = jdbcTemplate.update(
                "INSERT INTO orders (order_id, status, version) VALUES (?, ?, ?)",
                orderId, "PENDING", 0
            );

            if (rowsAffected == 0) {
                throw new DuplicateOrderException("Order already exists.");
            }

            // 继续处理其他业务逻辑...
        } catch (DuplicateKeyException e) {
            // 查询现有订单并返回
            Order existingOrder = jdbcTemplate.queryForObject(
                "SELECT * FROM orders WHERE order_id = ?",
                new Object[]{orderId},
                new BeanPropertyRowMapper<>(Order.class)
            );
            return existingOrder;
        }
    }
} catch (InterruptedException e) {
    Thread.currentThread().interrupt();
} finally {
    lock.unlock();
}