Redis分布式锁

直接上代码

package xxx.xxx.common.utils;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.data.redis.core.script.RedisScript;
import org.springframework.stereotype.Component;

import java.util.Collections;
import java.util.concurrent.TimeUnit;

/**
 * @Description: Redis分布式锁
 * @author: wph
 * @date: 2021/11/29
 */
@Component
@Slf4j
public class RedisLock {
    private static final Long SUCCESS_UNLOCK = 1L;
    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    /**
     * redis 加锁
     * key 锁的key
     * value 锁的值，用于解锁
     * expireTime 失效时间 单位：SECONDS
     */
    public boolean tryLockForSpin(String key, String value, long expireTime, long spinTimeOut) {
        Long start = System.currentTimeMillis();
        try {
            for (; ; ) {
                log.debug("尝试获取锁，当前线程ID{}", Thread.currentThread().getId());
                boolean ret = redisTemplate.opsForValue().setIfAbsent(key, value, expireTime, TimeUnit.SECONDS);
                if (ret) {
                    log.debug("获取锁成功，当前线程ID{}", Thread.currentThread().getId());
                    return true;
                }
                //否则循环等待，在spinTimeOut时间内仍未获取到锁，则获取失败
                long end = System.currentTimeMillis() - start;
                if (end >= spinTimeOut) {
                    return false;
                }
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return false;
    }
    /**
     * redis 加锁
     * key 锁的key
     * value 锁的值，用于解锁
     * expireTime 失效时间 单位：SECONDS
     * isSpin 是否需要自旋循环获取锁（未获取）
     * spinTimeOut 自旋的过期时间
     */
    public boolean tryLock(String key, String value, long expireTime,boolean isSpin,long spinTimeOut) {
        if (isSpin){
            return tryLockForSpin(key, value, expireTime,spinTimeOut);
        }else{
            try {
                log.debug("尝试获取锁，当前线程ID{}", Thread.currentThread().getId());
                boolean ret = redisTemplate.opsForValue().setIfAbsent(key, value, expireTime, TimeUnit.SECONDS);
                if (ret) {
                    log.debug("获取锁成功，当前线程ID{}", Thread.currentThread().getId());
                    return true;
                }
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            return false;
        }
    }
    /**
     * @Description: 释放锁
     * @date: 2021/11/29
     * @param key
     * @param value
     */
    public boolean unlock(String key, String value) {
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        RedisScript<String> redisScript = new DefaultRedisScript<>(script, String.class);
        Object result = redisTemplate.execute(redisScript, Collections.singletonList(key), value);
        if (SUCCESS_UNLOCK.equals(result)) {
            log.debug("释放锁成功，当前线程ID{}", Thread.currentThread().getId());
            return true;
        }
        return false;
    }
}