Spring Boot中使用Redis和Lua脚本实现延时队列

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Component;
 
import java.util.Collections;
import java.util.List;
 
@Component
public class DelayQueue {
 
    private static final Long RELEASE_LOCK_SCRIPT_TIMEOUT = 10000L;
    private final DefaultRedisScript<Long> releaseLockScript;
    private final StringRedisTemplate stringRedisTemplate;
 
    @Autowired
    public DelayQueue(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.releaseLockScript = new DefaultRedisScript<>();
        releaseLockScript.setScriptText(
                "local lockKey = KEYS[1] " +
                "local identifier = ARGV[1] " +
                "local currentIdentifier = redis.call('get', lockKey) " +
                "if currentIdentifier == identifier then " +
                "    return redis.call('del', lockKey) " +
                "else " +
                "    return 0 " +
                "end");
        releaseLockScript.setResultType(Long.class);
    }
 
    public boolean tryAcquireLock(String lockKey, String identifier) {
        // 尝试获取锁，成功返回true，失败返回false
        // 这里需要实现具体的逻辑
    }
 
    public void releaseLock(String lockKey, String identifier) {
        // 使用Lua脚本安全地释放锁
        List<String> keys = Collections.singletonList(lockKey);
        Long result = stringRedisTemplate.execute(releaseLockScript, keys, identifier);
        if (result != null && result.equals(1L)) {
            // 释放锁成功
        } else {
            // 释放锁失败或没有获得锁
        }
    }
}

这个代码实例展示了如何在Spring Boot应用中使用Redis和Lua脚本来实现一个简单的延时队列。其中tryAcquireLock方法需要根据具体需求实现。releaseLock方法使用了Lua脚本来安全地释放锁，避免了在释放锁时可能出现的竞争条件问题。