redisUtils工具类--RedisTemplate实现

林龙野
2023-12-01

配置文件:bootstrap-dev.yml

 redis:
    database: 0
    host: iac-redis-dev-tech.ikunchi.com
    port: 30038
    password:
    timeout: 60000ms
    jedis:
      pool:
        # 连接池最大阻塞等待时间(使用负值表示没有限制)
        max-wait: -1ms
        # 连接池最大连接数(使用负值表示没有限制)
        max-active: -1

 

RedisConfig.java

@Configuration
public class RedisConfig {

    @Bean
    @SuppressWarnings("all")
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();
        template.setConnectionFactory(factory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        // key采用String的序列化方式
        template.setKeySerializer(stringRedisSerializer);
        // hash的key也采用String的序列化方式
        template.setHashKeySerializer(stringRedisSerializer);
        // value序列化方式采用jackson
        template.setValueSerializer(jackson2JsonRedisSerializer);
        // hash的value序列化方式采用jackson
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        template.afterPropertiesSet();
        return template;
    }
}

 

 

CacheService.java

@Service
public class CacheService {

    private static Logger logger = LoggerFactory.getLogger(CacheService.class);

    private static final Long SUCCESS = 1L;

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    /**
     * 指定缓存失效时间
     *
     * @param key  键
     * @param time 时间(秒)
     * @return
     */
    public boolean expire(String key, long time) {
        try {
            if (time > 0) {
                redisTemplate.expire(key, time, TimeUnit.SECONDS);
            }
            return true;
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return false;
        }
    }

    /**
     * 根据key 获取过期时间
     *
     * @param key 键 不能为null
     * @return 时间(秒) 返回0代表为永久有效
     */

    public long getExpire(String key) {
        return redisTemplate.getExpire(key, TimeUnit.SECONDS);
    }

    /**
     * 判断key是否存在
     *
     * @param key 键
     * @return true 存在 false不存在
     */
    public boolean hasKey(String key) {
        try {
            return redisTemplate.hasKey(key);
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return false;
        }
    }

    /**
     * 删除缓存
     *
     * @param key 可以传一个值 或多个
     */
    @SuppressWarnings("unchecked")
    public void del(String... key) {
        if (key != null && key.length > 0) {
            if (key.length == 1) {
                redisTemplate.delete(key[0]);
            } else {
                redisTemplate.delete(CollectionUtils.arrayToList(key));
            }
        }
    }

    /**
     * 普通缓存获取
     *
     * @param key 键
     * @return 值
     */
    public Object get(String key) {
        return key == null ? null : redisTemplate.opsForValue().get(key);
    }

    /**
     * 普通缓存放入
     *
     * @param key   键
     * @param value 值
     * @return true成功 false失败
     */
    public boolean set(String key, Object value) {
        try {
            redisTemplate.opsForValue().set(key, value);
            return true;
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return false;
        }
    }

    /**
     * 普通缓存放入并设置时间
     *
     * @param key   键
     * @param value 值
     * @param time  时间(秒) time要大于0 如果time小于等于0 将设置无限期
     * @return true成功 false 失败
     */
    public boolean set(String key, Object value, long time) {
        try {
            if (time > 0) {
                redisTemplate.opsForValue().set(key, value, time, TimeUnit.SECONDS);
            } else {
                set(key, value);
            }
            return true;
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return false;
        }
    }

    /**
     * 递增
     *
     * @param key   键
     * @param delta 要增加几(大于0)
     * @return
     */
    public long incr(String key, long delta) {
        if (delta < 0) {
            throw new RuntimeException("递增因子必须大于0");
        }
        return redisTemplate.opsForValue().increment(key, delta);
    }

    /**
     * 递减
     *
     * @param key   键
     * @param delta 要减少几(小于0)
     * @return 147
     */
    public long decr(String key, long delta) {
        if (delta < 0) {
            throw new RuntimeException("递减因子必须大于0");
        }
        return redisTemplate.opsForValue().increment(key, -delta);
    }

    /**
     * 获取分布式锁
     * @param lockKey 锁
     * @param requestId 请求标识
     * @param expireTime 单位秒
     * @param waitTimeout 单位毫秒
     * @return 是否获取成功
     */
    public boolean tryLock(String lockKey, String requestId, int expireTime,long waitTimeout) {
        long nanoTime = System.nanoTime(); // 当前时间
        try{
            String script = "if redis.call('setNx',KEYS[1],ARGV[1]) then if redis.call('get',KEYS[1])==ARGV[1] then return redis.call('expire',KEYS[1],ARGV[2]) else return 0 end end";

            logger.info("开始获取分布式锁-key[{}]",lockKey);
            int count = 0;
            do{
                RedisScript<String> redisScript = new DefaultRedisScript<>(script, String.class);

                logger.debug("尝试获取分布式锁-key[{}]requestId[{}]count[{}]",lockKey,requestId,count);
                Object result = redisTemplate.execute(redisScript, Collections.singletonList(lockKey),requestId,expireTime);

                if(SUCCESS.equals(result)) {
                    logger.debug("尝试获取分布式锁-key[{}]成功",lockKey);
                    return true;
                }

                Thread.sleep(500L);//休眠500毫秒
                count++;
            }while ((System.nanoTime() - nanoTime) < TimeUnit.MILLISECONDS.toNanos(waitTimeout));

        }catch(Exception e){
            logger.error("尝试获取分布式锁-key[{}]异常",lockKey);
            logger.error(e.getMessage(),e);
        }

        return false;
    }

    /**
     * 释放锁
     * @param lockKey 锁
     * @param requestId 请求标识
     * @return 是否释放成功
     */
    public boolean releaseLock(String lockKey, String requestId) {

        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(lockKey), requestId);
        if (SUCCESS.equals(result)) {
            return true;
        }

        return false;

    }
}
 

 加锁另一种方式,试过可用,上面未验证

/***
 * 加锁
 * @param key
 * @param value 当前时间+超时时间
 * @return 锁住返回true
 */
public boolean lock(String key,String value){
    if(stringRedisTemplate.opsForValue().setIfAbsent(key,value)){//setNX 返回boolean
        return true;
    }
    //如果锁超时 ***
    String currentValue = stringRedisTemplate.opsForValue().get(key);
    if(!StringUtils.isEmpty(currentValue) && Long.parseLong(currentValue)<System.currentTimeMillis()){
        //获取上一个锁的时间
        String oldvalue  = stringRedisTemplate.opsForValue().getAndSet(key,value);
        if(!StringUtils.isEmpty(oldvalue)&&oldvalue.equals(currentValue)){
            return true;
        }
    }
    return false;
}
/***
 * 解锁
 * @param key
 * @param value
 * @return
 */
public void unlock(String key,String value){
    try {
        String currentValue = stringRedisTemplate.opsForValue().get(key);
        if(!StringUtils.isEmpty(currentValue)&&currentValue.equals(value)){
            stringRedisTemplate.opsForValue().getOperations().delete(key);
        }
    } catch (Exception e) {
        log.error("解锁异常");
    }
}

 

转载于:https://www.cnblogs.com/yoishion/p/11314376.html

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