Redis集群是没法执行批量操作命令的，如mget，pipeline等。这是因为redis将集群划分为16383个哈希槽，不同的key会划分到不同的槽中。但是，Jedis客户端提供了计算key的slot方法，已经slot和节点之间的映射关系，通过这两个数据，就可以计算出每个key所在的节点，然后使用pipeline获取数据。具体代码如下：

初始化    JedisCluster类

@Configurationpublic class JedisClusterConfig {    @Value("${spring.redis.cluster.nodes}")    private String clusterNodes;    @Value("${spring.redis.cache.commandTimeout}")    private Integer commandTimeout;    @Bean    public JedisCluster getJedisCluster() {        String[] serverArray = clusterNodes.split(",");        Set<HostAndPort> nodes = new HashSet<>();        for (String ipPort : serverArray) {            String[] ipPortPair = ipPort.split(":");            nodes.add(new HostAndPort(ipPortPair[0].trim(), Integer.valueOf(ipPortPair[1].trim())));        }        return new JedisCluster(nodes, commandTimeout);    }}

工具类 JedisClusterUtil

@Componentpublic class JedisClusterUtil {    @Autowired    private JedisCluster jedisCluster;    @Resource(name = "redisTemplate4Json")    protected RedisTemplate<String, Object> redisTemplate;    /**     * ZSet批量查询     * @param keys     * @return     */    public List<Object> batchZRange(List<String> keys) {        List<Object> resList = new ArrayList<>();        if (keys == null || keys.size() == 0) {            return resList;        }        if (keys.size() == 1) {            BoundZSetOperations<String, Object> operations = redisTemplate.boundZSetOps(keys.get(0));            Set<Object> set = operations.reverseRange(0, 0);            resList.add(set.iterator().next());            return resList;        }        Map<JedisPool, List<String>> jedisPoolMap = getJedisPool(keys);        List<String> keyList;        JedisPool currentJedisPool = null;        Pipeline currentPipeline;        List<Object> res = new ArrayList<>();        Map<String, Object> resultMap = new HashMap<>();        //执行        for (Map.Entry<JedisPool, List<String>> entry : jedisPoolMap.entrySet()) {            Jedis jedis = null;            try {                currentJedisPool = entry.getKey();                keyList = entry.getValue();                //获取pipeline                jedis = currentJedisPool.getResource();                currentPipeline = jedis.pipelined();                for (String key : keyList) {                    currentPipeline.zrevrange(key, 0, 0);                }                //从pipeline中获取结果                res = currentPipeline.syncAndReturnAll();                currentPipeline.close();                for (int i = 0; i < keyList.size(); i++) {                    if (null == res.get(i)) {                        resultMap.put(keyList.get(i), null);                    } else {                        Set<Object> set = (Set<Object>) res.get(i);                        if (null == set || set.isEmpty()) {                            resultMap.put(keyList.get(i), null);                        } else {                            byte[] byteStr = set.iterator().next().toString().getBytes();                            Object obj = redisTemplate.getDefaultSerializer().deserialize(byteStr);                            resultMap.put(keyList.get(i), obj);                        }                    }                }            } catch (Exception e) {                e.printStackTrace();            } finally {                returnResource(jedis, currentJedisPool);            }        }        resList = sortList(keys, resultMap);        return resList;    }    /**     * Value批量查询     * @param keys     * @return     */    public List<Object> batchGet(List<String> keys){        List<Object> resList = new ArrayList<>();        if (keys == null || keys.size() == 0) {            return resList;        }        if (keys.size() == 1) {            BoundValueOperations<String, Object> operations = redisTemplate.boundValueOps(keys.get(0));            resList.add(operations.get());            return resList;        }        Map<JedisPool, List<String>> jedisPoolMap = getJedisPool(keys);        List<String> keyList;        JedisPool currentJedisPool = null;        Pipeline currentPipeline;        List<Object> res = new ArrayList<>();        Map<String, Object> resultMap = new HashMap<>();        for (Map.Entry<JedisPool, List<String>> entry : jedisPoolMap.entrySet()) {            Jedis jedis = null;            try {                currentJedisPool = entry.getKey();                keyList = entry.getValue();                //获取pipeline                jedis = currentJedisPool.getResource();                currentPipeline = jedis.pipelined();                for (String key : keyList) {                    currentPipeline.get(key);                }                //从pipeline中获取结果                res = currentPipeline.syncAndReturnAll();                currentPipeline.close();                for (int i = 0; i < keyList.size(); i++) {                    if (null == res.get(i)) {                        resultMap.put(keyList.get(i), null);                    } else {                        byte[] byteStr = keyList.get(i).toString().getBytes();                        Object obj = redisTemplate.getDefaultSerializer().deserialize(byteStr);                        resultMap.put(keyList.get(i), obj);                    }                }            } catch (Exception e) {                e.printStackTrace();            } finally {                returnResource(jedis, currentJedisPool);            }        }        resList = sortList(keys, resultMap);        return resList;    }    private Map<JedisPool, List<String>> getJedisPool(List<String> keys){        //JedisCluster继承了BinaryJedisCluster        //BinaryJedisCluster的JedisClusterConnectionHandler属性        //里面有JedisClusterInfoCache，根据这一条继承链，可以获取到JedisClusterInfoCache        //从而获取slot和JedisPool直接的映射        MetaObject metaObject = SystemMetaObject.forObject(jedisCluster);        JedisClusterInfoCache cache = (JedisClusterInfoCache) metaObject.getValue("connectionHandler.cache");        //保存地址+端口和命令的映射        Map<JedisPool, List<String>> jedisPoolMap = new HashMap<>();        JedisPool currentJedisPool = null;        List<String> keyList;        for (String key : keys) {            //计算哈希槽            int crc = JedisClusterCRC16.getSlot(key);            //通过哈希槽获取节点的连接            currentJedisPool = cache.getSlotPool(crc);            //由于JedisPool作为value保存在JedisClusterInfoCache中的一个map对象中，每个节点的            //JedisPool在map的初始化阶段就是确定的和唯一的，所以获取到的每个节点的JedisPool都是一样            //的，可以作为map的key            if (jedisPoolMap.containsKey(currentJedisPool)) {                jedisPoolMap.get(currentJedisPool).add(key);            } else {                keyList = new ArrayList<>();                keyList.add(key);                jedisPoolMap.put(currentJedisPool, keyList);            }        }        return jedisPoolMap;    }    private List<Object> sortList(List<String> keys, Map<String, Object> params) {        List<Object> resultList = new ArrayList<>();        Iterator<String> it = keys.iterator();        while (it.hasNext()) {            String key = it.next();            resultList.add(params.get(key));        }        return resultList;    }    /**     * 释放jedis资源     *     * @param jedis     */    public void returnResource(Jedis jedis, JedisPool jedisPool) {        if (jedis != null && jedisPool != null) {            jedisPool.returnResource(jedis);        }    }

 注意：一定要完成后释放 jedis 资源  不然会造成卡死现象

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标签：节点,批量,集群,操作,初始化