标签：pipeline JedisCluster currentJedisPool keys List 管道 jedis key keyList

package com.meiya.whale.mining.redis;


import org.apache.commons.lang3.StringUtils;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import redis.clients.jedis.*;
import redis.clients.util.JedisClusterCRC16;

import java.util.*;

@Component
public class JedisClusterUtil {

    @Autowired
    private JedisCluster jedisCluster;

    /**
     * Value批量查询
     *
     * @param keys
     * @return
     */
    public List<Object> batchGet(List<String> keys,String field) {
        List<Object> resList = new ArrayList<>();
        if (keys == null || keys.size() == 0) {
            return resList;
        }

        if (keys.size() == 1) {
            Map<String, String> map = jedisCluster.hgetAll(keys.get(0));
            resList.add(map);
            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) {
                    if(StringUtils.isNotBlank(field)){
                        currentPipeline.hget(key,field);
                    }else {
                        currentPipeline.hgetAll(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 {
                        resultMap.put(keyList.get(i), res.get(i));
                    }
                }
            } 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);
        }
    }
}

标签：pipeline,JedisCluster,currentJedisPool,keys,List,管道,jedis,key,keyList
来源： https://www.cnblogs.com/hyh123/p/15262114.html

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