转自:
http://flyingsnail.blog.51cto.com/5341669/1371650
一、相关jar包
主要用到的是jedis的核心包，笔者用到的是2.1.0版；另根据“池”的应用等还需要用到相关jar包。下图是笔者建立的简单的jedis测试project图：
jar包的文档可参考：
二、简单的Jedis实例
在引入相关jar包后，只要new一个Jedis对象，就能做redis相关操作了。以下是一个简单的jedis实例：
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package com.pptv.redis;import java.util.ArrayList;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Set;import redis.clients.jedis.Jedis;public class JedisDemo {public void test(){Jedis redis = new Jedis ("172.0.0.1",6379);//连接redisredis.auth("redis");//验证密码,如果需要验证的话// STRING 操作//SET key value将字符串值value关联到key。redis.set("name", "wangjun1");redis.set("id", "123456");redis.set("address", "guangzhou");//SETEX key seconds value将值value关联到key，并将key的生存时间设为seconds(以秒为单位)。redis.setex("foo", 5, "haha");//MSET key value [key value ...]同时设置一个或多个key-value对。redis.mset("haha","111","xixi","222");//redis.flushAll();清空所有的keySystem.out.println(redis.dbSize());//dbSize是多少个key的个数//APPEND key value如果key已经存在并且是一个字符串，APPEND命令将value追加到key原来的值之后。redis.append("foo", "00");//如果key已经存在并且是一个字符串，APPEND命令将value追加到key原来的值之后。//GET key 返回key所关联的字符串值redis.get("foo");//MGET key [key ...] 返回所有(一个或多个)给定key的值List list = redis.mget("haha","xixi");for(int i=0;i<list.size();i++){System.out.println(list.get(i));}}public static void main(String[] args) {JedisDemo t1 = new JedisDemo();t1.test();}} |
三、JedisPool应用
Jedis使用commons-pool完成池化实现。
先做个配置文件(properties文件)：
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#最大分配的对象数redis.pool.maxActive=1024#最大能够保持idel状态的对象数redis.pool.maxIdle=200#当池内没有返回对象时，最大等待时间redis.pool.maxWait=1000#当调用borrow Object方法时，是否进行有效性检查redis.pool.testOnBorrow=true#当调用return Object方法时，是否进行有效性检查redis.pool.testOnReturn=true#IPredis.ip=172.0.0.1#Portredis.port=6379 |
jedisPool的相关详细配置可参考：http://www.2cto.com/database/201311/254449.html
在静态代码段中完成初始化：
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private static JedisPool pool;static {ResourceBundle bundle = ResourceBundle.getBundle("redis");if (bundle == null) {throw new IllegalArgumentException("[redis.properties] is not found!");}JedisPoolConfig config = new JedisPoolConfig();config.setMaxActive(Integer.valueOf(bundle.getString("redis.pool.maxActive")));config.setMaxIdle(Integer.valueOf(bundle.getString("redis.pool.maxIdle")));config.setMaxWait(Long.valueOf(bundle.getString("redis.pool.maxWait")));config.setTestOnBorrow(Boolean.valueOf(bundle.getString("redis.pool.testOnBorrow")));config.setTestOnReturn(Boolean.valueOf(bundle.getString("redis.pool.testOnReturn")));pool = new JedisPool(config, bundle.getString("redis.ip"),Integer.valueOf(bundle.getString("redis.port")));} |
然后修改#2的简单实例，修改为Jedis从pool中获得：
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// 从池中获取一个Jedis对象Jedis jedis = pool.getResource();String keys = "name";// 删数据jedis.del(keys);// 存数据jedis.set(keys, "snowolf");// 取数据String value = jedis.get(keys);System.out.println(value);// 释放对象池pool.returnResource(jedis); |
四、Jedis分布式（Sharding/shared一致性哈希）
Memcached完全基于分布式集群，而Redis是Master-Slave，如果想把Reids，做成集群模式，无外乎多做几套Master-Slave，每套Master-Slave完成各自的容灾处理，通过Client工具，完成一致性哈希。（PS:Memcached是在Server端完成Sharding，Redis只能依靠各个Client做Sharding。可能会在Redis 3.0系列支持Server端Sharding。）
shared一致性哈希采用以下方案：
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Redis服务器节点划分：将每台服务器节点采用hash算法划分为160个虚拟节点(可以配置划分权重)
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将划分虚拟节点采用TreeMap存储
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对每个Redis服务器的物理连接采用LinkedHashMap存储
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对Key or KeyTag 采用同样的hash算法，然后从TreeMap获取大于等于键hash值得节点，取最邻近节点存储；当key的hash值大于虚拟节点hash值得最大值时，存入第一个虚拟节点
sharded采用的hash算法：MD5 和 MurmurHash两种；默认采用64位的MurmurHash算法；有兴趣的可以研究下，MurmurHash是一种高效，低碰撞的hash算法；参考地址：
保留前面的JedisPoolConfig，新增两个Redis的IP（redis1.ip，redis2.ip），完成两个JedisShardInfo实例，并将其丢进List中：
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JedisShardInfo jedisShardInfo1 = new JedisShardInfo(bundle.getString("redis1.ip"), Integer.valueOf(bundle .getString("redis.port")));JedisShardInfo jedisShardInfo2 = new JedisShardInfo(bundle.getString("redis2.ip"), Integer.valueOf(bundle .getString("redis.port")));List<JedisShardInfo> list = new LinkedList<JedisShardInfo>();list.add(jedisShardInfo1);list.add(jedisShardInfo2); |
初始化ShardedJedisPool代替JedisPool：
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ShardedJedisPool pool = new ShardedJedisPool(config, list); |
改由ShardedJedis，获取Jedis对象：
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// 从池中获取一个Jedis对象ShardedJedis jedis = pool.getResource();String keys = "name";String value = "snowolf";// 删数据jedis.del(keys);// 存数据jedis.set(keys, value);// 取数据String v = jedis.get(keys);System.out.println(v);// 释放对象池pool.returnResource(jedis); |
通过以上方式，向redis进行set操作的key-value，会通过hash而均匀的分配到pool里的redis机器中。
五、综合实例
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package com.pptv.redis;import java.util.ArrayList;import java.util.List;import redis.clients.jedis.Jedis;import redis.clients.jedis.JedisPool;import redis.clients.jedis.JedisPoolConfig;import redis.clients.jedis.JedisShardInfo;import redis.clients.jedis.ShardedJedis;import redis.clients.jedis.ShardedJedisPool;/*** redis的Java客户端Jedis测试验证** @author*/public class Test {/*** 非切片客户端链接*/private Jedis jedis;/*** 非切片链接池*/private JedisPool jedisPool;/*** 切片客户端链接*/private ShardedJedis shardedJedis;/*** 切片链接池*/private ShardedJedisPool shardedJedisPool;private String ip = "172.16.205.186";/*** 构造函数*/public Test() {initialPool();initialShardedPool();shardedJedis = shardedJedisPool.getResource();jedis = jedisPool.getResource();}private void initialPool() {// 池基本配置JedisPoolConfig config = new JedisPoolConfig();config.setMaxActive(20);config.setMaxIdle(5);config.setMaxWait(1000l);config.setTestOnBorrow(false);jedisPool = new JedisPool(config, ip, 6379);}/*** 初始化切片池*/private void initialShardedPool() {// 池基本配置JedisPoolConfig config = new JedisPoolConfig();config.setMaxActive(20);config.setMaxIdle(5);config.setMaxWait(1000l);config.setTestOnBorrow(false);// slave链接List<JedisShardInfo> shards = new ArrayList<JedisShardInfo>();shards.add(new JedisShardInfo(ip, 6379, "master"));// 构造池shardedJedisPool = new ShardedJedisPool(config, shards);}public void show() {// key检测testKey();// string检测testString();// list检测testList();// set检测testSet();// sortedSet检测testSortedSet();// hash检测testHash();shardedJedisPool.returnResource(shardedJedis);}private void testKey() {System.out.println("=============key==========================");// 清空数据System.out.println(jedis.flushDB());System.out.println(jedis.echo("foo"));// 判断key否存在System.out.println(shardedJedis.exists("foo"));shardedJedis.set("key", "values");System.out.println(shardedJedis.exists("key"));}private void testString() {System.out.println("=============String==========================");// 清空数据System.out.println(jedis.flushDB());// 存储数据shardedJedis.set("foo", "bar");System.out.println(shardedJedis.get("foo"));// 若key不存在，则存储shardedJedis.setnx("foo", "foo not exits");System.out.println(shardedJedis.get("foo"));// 覆盖数据shardedJedis.set("foo", "foo update");System.out.println(shardedJedis.get("foo"));// 追加数据shardedJedis.append("foo", " hello, world");System.out.println(shardedJedis.get("foo"));// 设置key的有效期，并存储数据shardedJedis.setex("foo", 2, "foo not exits");System.out.println(shardedJedis.get("foo"));try {Thread.sleep(3000);} catch (InterruptedException e) {}System.out.println(shardedJedis.get("foo"));// 获取并更改数据shardedJedis.set("foo", "foo update");System.out.println(shardedJedis.getSet("foo", "foo modify"));// 截取value的值System.out.println(shardedJedis.getrange("foo", 1, 3));System.out.println(jedis.mset("mset1", "mvalue1", "mset2", "mvalue2","mset3", "mvalue3", "mset4", "mvalue4"));System.out.println(jedis.mget("mset1", "mset2", "mset3", "mset4"));System.out.println(jedis.del(new String[] { "foo", "foo1", "foo3" }));}private void testList() {System.out.println("=============list==========================");// 清空数据System.out.println(jedis.flushDB());// 添加数据shardedJedis.lpush("lists", "vector");shardedJedis.lpush("lists", "ArrayList");shardedJedis.lpush("lists", "LinkedList");// 数组长度System.out.println(shardedJedis.llen("lists"));// 排序// System.out.println(shardedJedis.sort("lists"));// 字串System.out.println(shardedJedis.lrange("lists", 0, 3));// 修改列表中单个值shardedJedis.lset("lists", 0, "hello list!");// 获取列表指定下标的值System.out.println(shardedJedis.lindex("lists", 1));// 删除列表指定下标的值System.out.println(shardedJedis.lrem("lists", 1, "vector"));// 删除区间以外的数据System.out.println(shardedJedis.ltrim("lists", 0, 1));// 列表出栈System.out.println(shardedJedis.lpop("lists"));// 整个列表值System.out.println(shardedJedis.lrange("lists", 0, -1));}private void testSet() {System.out.println("=============set==========================");// 清空数据System.out.println(jedis.flushDB());// 添加数据shardedJedis.sadd("sets", "HashSet");shardedJedis.sadd("sets", "SortedSet");shardedJedis.sadd("sets", "TreeSet");// 判断value是否在列表中System.out.println(shardedJedis.sismember("sets", "TreeSet"));;// 整个列表值System.out.println(shardedJedis.smembers("sets"));// 删除指定元素System.out.println(shardedJedis.srem("sets", "SortedSet"));// 出栈System.out.println(shardedJedis.spop("sets"));System.out.println(shardedJedis.smembers("sets"));//shardedJedis.sadd("sets1", "HashSet1");shardedJedis.sadd("sets1", "SortedSet1");shardedJedis.sadd("sets1", "TreeSet");shardedJedis.sadd("sets2", "HashSet2");shardedJedis.sadd("sets2", "SortedSet1");shardedJedis.sadd("sets2", "TreeSet1");// 交集System.out.println(jedis.sinter("sets1", "sets2"));// 并集System.out.println(jedis.sunion("sets1", "sets2"));// 差集System.out.println(jedis.sdiff("sets1", "sets2"));}private void testSortedSet() {System.out.println("=============zset==========================");// 清空数据System.out.println(jedis.flushDB());// 添加数据shardedJedis.zadd("zset", 10.1, "hello");shardedJedis.zadd("zset", 10.0, ":");shardedJedis.zadd("zset", 9.0, "zset");shardedJedis.zadd("zset", 11.0, "zset!");// 元素个数System.out.println(shardedJedis.zcard("zset"));// 元素下标System.out.println(shardedJedis.zscore("zset", "zset"));// 集合子集System.out.println(shardedJedis.zrange("zset", 0, -1));// 删除元素System.out.println(shardedJedis.zrem("zset", "zset!"));System.out.println(shardedJedis.zcount("zset", 9.5, 10.5));// 整个集合值System.out.println(shardedJedis.zrange("zset", 0, -1));}private void testHash() {System.out.println("=============hash==========================");// 清空数据System.out.println(jedis.flushDB());// 添加数据shardedJedis.hset("hashs", "entryKey", "entryValue");shardedJedis.hset("hashs", "entryKey1", "entryValue1");shardedJedis.hset("hashs", "entryKey2", "entryValue2");// 判断某个值是否存在System.out.println(shardedJedis.hexists("hashs", "entryKey"));// 获取指定的值System.out.println(shardedJedis.hget("hashs", "entryKey"));// 批量获取指定的值System.out.println(shardedJedis.hmget("hashs", "entryKey", "entryKey1"));// 删除指定的值System.out.println(shardedJedis.hdel("hashs", "entryKey"));// 为key中的域 field 的值加上增量 incrementSystem.out.println(shardedJedis.hincrBy("hashs", "entryKey", 123l));// 获取所有的keysSystem.out.println(shardedJedis.hkeys("hashs"));// 获取所有的valuesSystem.out.println(shardedJedis.hvals("hashs"));}/*** @param args*/public static void main(String[] args) {new Test().show();}} |
