com.feingto.cloud.cache.provider.RedisLock Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of feingto-cache Show documentation

There is a newer version: 2.5.2.RELEASE

package com.feingto.cloud.cache.provider;

import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.util.StringUtils;

import java.util.Objects;
import java.util.concurrent.TimeUnit;

/**
 * Redis 分布式锁
 *
 * @author longfei
 */
public class RedisLock {
    private final ValueOperations operations;

    public RedisLock(RedisTemplate redisTemplate) {
        this.operations = redisTemplate.opsForValue();
    }

    /**
     * 加锁
     *
     * @param key       键
     * @param lockValue 当前锁值
     */
    public boolean lock(String key, String lockValue) {
        return this.lock(key, lockValue, null);
    }

    /**
     * 加锁
     *
     * @param key         键
     * @param lockValue   当前锁值
     * @param lockSeconds 锁定秒数
     */
    public boolean lock(String key, String lockValue, Integer lockSeconds) {
        if (Objects.nonNull(lockSeconds) && operations.setIfAbsent(key, lockValue, lockSeconds, TimeUnit.SECONDS)) {
            return true;
        } else if (Objects.isNull(lockSeconds) && operations.setIfAbsent(key, lockValue)) {
            return true;
        }

        String current = operations.get(key);
        if (StringUtils.hasText(current) && Long.parseLong(current) < System.currentTimeMillis()) {
            String old = operations.getAndSet(key, lockValue);
            return StringUtils.hasText(old) && old.equals(current);
        }

        return false;
    }

    /**
     * 解锁
     *
     * @param key       键
     * @param lockValue 当前锁值
     */
    public void unlock(String key, String lockValue) {
        try {
            String current = operations.get(key);
            if (StringUtils.hasText(current) && current.equals(lockValue)) {
                operations.getOperations().delete(key);
            }
        } catch (Exception ignored) {
        }
    }

    /**
     * 获取当前锁值
     *
     * @param expireTime 有效期秒数
     * @return 当前时间毫秒数 + 超时时间毫秒数
     */
    public String getLockValue(long expireTime) {
        return String.valueOf(System.currentTimeMillis() + expireTime * 1000);
    }
}