2018.7.27 java电商从1到2--chapter7 单点登录+redis分布式

在chapter6中已经使用redis+cookie+jackson+filter来实现单点登录。

这里进行进一步优化，使用分布式redis。

7.1 总览

• redis分布式算法--一致性hash
• ShardedJedis

7.2 一致性hash

参考来自：https://blog.csdn.net/lihao21/article/details/54193868

一致性hash中为了降低hash倾斜的影响，引入了虚拟节点，并说明了为什么可以降低影响。后面学习ShardedJedisPool的源码时可以发现，其父亲是默认添加虚拟节点的。

7.3 RedisShardedPool和RedisShardedPoolUtil

7.3.1 依赖和配置

不用动，和之前一样。

7.3.2 RedisShardedPool

涉及到的重要类：

• ShardedJedisPool
• ShardedJedis
• JedisPoolConfig
• JedisShardInfo
• Hashing.MURMUR_HASH

package com.mmall.common;

import com.mmall.util.PropertiesUtil;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.jedis.JedisShardInfo;
import redis.clients.jedis.ShardedJedis;
import redis.clients.jedis.ShardedJedisPool;
import redis.clients.util.Hashing;
import redis.clients.util.Sharded;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by geely
 */
public class RedisShardedPool {
    private static ShardedJedisPool pool;//sharded jedis连接池
    private static Integer maxTotal = Integer.parseInt(PropertiesUtil.getProperty("redis.max.total","20")); //最大连接数
    private static Integer maxIdle = Integer.parseInt(PropertiesUtil.getProperty("redis.max.idle","20"));//在jedispool中最大的idle状态(空闲的)的jedis实例的个数
    private static Integer minIdle = Integer.parseInt(PropertiesUtil.getProperty("redis.min.idle","20"));//在jedispool中最小的idle状态(空闲的)的jedis实例的个数

    private static Boolean testOnBorrow = Boolean.parseBoolean(PropertiesUtil.getProperty("redis.test.borrow","true"));//在borrow一个jedis实例的时候，是否要进行验证操作，如果赋值true。则得到的jedis实例肯定是可以用的。
    private static Boolean testOnReturn = Boolean.parseBoolean(PropertiesUtil.getProperty("redis.test.return","true"));//在return一个jedis实例的时候，是否要进行验证操作，如果赋值true。则放回jedispool的jedis实例肯定是可以用的。

    private static String redis1Ip = PropertiesUtil.getProperty("redis1.ip");
    private static Integer redis1Port = Integer.parseInt(PropertiesUtil.getProperty("redis1.port"));
    private static String redis2Ip = PropertiesUtil.getProperty("redis2.ip");
    private static Integer redis2Port = Integer.parseInt(PropertiesUtil.getProperty("redis2.port"));


    private static void initPool(){
        JedisPoolConfig config = new JedisPoolConfig();

        config.setMaxTotal(maxTotal);
        config.setMaxIdle(maxIdle);
        config.setMinIdle(minIdle);

        config.setTestOnBorrow(testOnBorrow);
        config.setTestOnReturn(testOnReturn);

        config.setBlockWhenExhausted(true);//连接耗尽的时候，是否阻塞，false会抛出异常，true阻塞直到超时。默认为true。

        JedisShardInfo info1 = new JedisShardInfo(redis1Ip,redis1Port,1000*2);
        JedisShardInfo info2 = new JedisShardInfo(redis2Ip,redis2Port,1000*2);

        List<JedisShardInfo> jedisShardInfoList = new ArrayList<JedisShardInfo>(2);
        jedisShardInfoList.add(info1);
        jedisShardInfoList.add(info2);

		//MURMUR_HASH对应的是一致性算法
        pool = new ShardedJedisPool(config,jedisShardInfoList, Hashing.MURMUR_HASH, Sharded.DEFAULT_KEY_TAG_PATTERN);
    }

    static{
        initPool();
    }

    public static ShardedJedis getJedis(){
        return pool.getResource();
    }

    public static void returnBrokenResource(ShardedJedis jedis){
        pool.returnBrokenResource(jedis);
    }

    public static void returnResource(ShardedJedis jedis){
        pool.returnResource(jedis);
    }


    public static void main(String[] args) {
        ShardedJedis jedis = pool.getResource();

        for(int i =0;i<10;i++){
            jedis.set("key"+i,"value"+i);
        }
        returnResource(jedis);

//        pool.destroy();//临时调用，销毁连接池中的所有连接
        System.out.println("program is end");
    }
}

7.3.3 RedisShardedPoolUtil

涉及到的重要类：

• RedisShardedPool
• ShardedJedis

package com.mmall.util;

import com.mmall.common.RedisShardedPool;
import lombok.extern.slf4j.Slf4j;
import redis.clients.jedis.ShardedJedis;

/**
 * Created by geely
 */
@Slf4j
public class RedisShardedPoolUtil {

    /**
     * 设置key的有效期，单位是秒
     * @param key
     * @param exTime
     * @return
     */
    public static Long expire(String key,int exTime){
        ShardedJedis jedis = null;
        Long result = null;
        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.expire(key,exTime);
        } catch (Exception e) {
            log.error("expire key:{} error",key,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }

    //exTime的单位是秒
    public static String setEx(String key,String value,int exTime){
        ShardedJedis jedis = null;
        String result = null;
        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.setex(key,exTime,value);
        } catch (Exception e) {
            log.error("setex key:{} value:{} error",key,value,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }

    public static String set(String key,String value){
        ShardedJedis jedis = null;
        String result = null;

        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.set(key,value);
        } catch (Exception e) {
            log.error("set key:{} value:{} error",key,value,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }

    public static String getSet(String key,String value){
        ShardedJedis jedis = null;
        String result = null;

        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.getSet(key,value);
        } catch (Exception e) {
            log.error("getset key:{} value:{} error",key,value,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }

    public static String get(String key){
        ShardedJedis jedis = null;
        String result = null;
        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.get(key);
        } catch (Exception e) {
            log.error("get key:{} error",key,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }

    public static Long del(String key){
        ShardedJedis jedis = null;
        Long result = null;
        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.del(key);
        } catch (Exception e) {
            log.error("del key:{} error",key,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }

    public static Long setnx(String key,String value){
        ShardedJedis jedis = null;
        Long result = null;

        try {
            jedis = RedisShardedPool.getJedis();
            result = jedis.setnx(key,value);
        } catch (Exception e) {
            log.error("setnx key:{} value:{} error",key,value,e);
            RedisShardedPool.returnBrokenResource(jedis);
            return result;
        }
        RedisShardedPool.returnResource(jedis);
        return result;
    }


    public static void main(String[] args) {
        ShardedJedis jedis = RedisShardedPool.getJedis();

        RedisPoolUtil.set("keyTest","value");
        String value = RedisPoolUtil.get("keyTest");
        RedisPoolUtil.setEx("keyex","valueex",60*10);
        RedisPoolUtil.expire("keyTest",60*20);
        RedisPoolUtil.del("keyTest");

        String aaa = RedisPoolUtil.get(null);
        System.out.println(aaa);

        System.out.println("end");
    }
}

7.4 使用RedisShardedPool和RedisShardedPoolUtil

略。将代码中用到RedisPool和RedisPoolUtil的地方改为RedisShardedPool和RedisShardedPoolUtil即可。