10. redis java client
十. redis java client
redis主页上列出的java 客户端有JDBC-Redis JRedis Jedis三种,下面分别介绍三种客户端的优缺点及其他相关的工具.
|
支持redis版本 | 性能 | 维护 | 推荐 |
JDBC-Redis | not good | |||
JRedis | 1.2.n release 2.0.0 尚未release版本 |
fast | ||
Jedis | 2.0.0 release | fast | actively developed | 推荐 |
JDBC-Redis
JDBC-Redis is just a JDBC wrapper for JRedis database.
If you plan on using your code with different back-ends then JDBC is a good way to go. NOTE: It is not a complete JDBC implementation and the NOSQL will bleed through.
If you are going to stay with Redis then I would suggest using the API, which will give you more flexibility. Use a DAO layer pattern to encapsulate your DB Access and down the road that is all you will need to change.
- Romain Hippeau
Redis syntax is completely different from standard SQL so using JDBC doesn't help encapsulating different back-ends as you suggest: I would have to write new queries anyway... – muriloq Jun 16 '10 at 14:00
@muriloq - but the mechanical acquiring and releasing resources is standard. – Romain Hippeau
spring wrapper
Spring provides a wrapper around both implementations(Jredis Jedis) and they're providing serialization/deserialization, amongst other things:
Person p = new Person("Joe", "Trader", 33); template.convertAndSet("trader:1", p); Person samePerson = template.getAndConvert("trader:1", Person.class); Assert.assertEquals(p, samePerson);
放弃spring wrapper
项目中本来打算使用spring wrapper,出于以下原因最终还是放弃,直接使用Jedis,等有时间在把:
1.spring wrapper的版本是1.0.0.M2,里面有些bug (*)
2.对shard的支持没有jedis好
3.依赖spring3.0(主要是spring3.0 core中的convert及serializer),我们目前大多项目还是采用spring2.5.6(主要)
4.经过多层封装后性能还是会有损耗
spring nosql/cross-store
prototype implementation allowing entities to be stored in multiple types of data stores (i.e. JPA and Neo4j or JPA and Redis etc.)
JOhm
JOhm is a blazingly fast Object-Hash Mapping library for Java inspired by the awesome Ohm. The JOhm OHM is a modern-day avatar of the old ORM's like Hibernate with the difference being that we are not dealing with an RDBMS here but with a NoSQL rockstar.
homepage:https://github.com/xetorthio/johm
jedis pool的问题
在使用jedis pool时遇到了这个问题:It seems like server has closed the connection
原因分析:
1.redis server 关闭了此客户端的连接:server端设置了maxidletime(默认是5分钟),服务端会不断循环检测clinet的最后一次通信时间(lastinteraction),如果大于maxidletime,则关闭连接,并回收相关资源。client在向该连接中写数据后就会由于server端已经关闭而出现 broken pipe的问题。
2.pool的设置错误:
<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<property name="maxActive" value="20" />
<property name="maxIdle" value="10" />
<property name="maxWait" value="1000" />
</bean>
<!-- jedis shard信息配置 -->
<bean id="jedis.shardInfo" class="redis.clients.jedis.JedisShardInfo">
<constructor-arg index="0" value="*.*.*.*" />
<constructor-arg index="1" value="6379" />
</bean>
<!-- jedis shard pool配置 -->
<bean id="shardedJedisPool" class="redis.clients.jedis.ShardedJedisPool">
<constructor-arg index="0" ref="jedisPoolConfig" />
<constructor-arg index="1">
<list>
<ref bean="jedis.shardInfo" />
</list>
</constructor-arg>
</bean>
<bean id="jedisCommands" factory-bean="shardedJedisPool"
factory-method="getResource" />
上面的这种配法在spring初始化时获取一次实例化jedisCommands,而后每次的redis的调用时并未从pool中获取
解决方案:
设置
<!-- POOL配置 --> <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig"> <property name="maxActive" value="20" /> <property name="maxIdle" value="10" /> <property name="maxWait" value="1000" /> <property name="testOnBorrow" value="true"/> </bean> <!-- jedis shard信息配置 --> <bean id="jedis.shardInfo" class="redis.clients.jedis.JedisShardInfo"> <constructor-arg index="0" value="*.*.*.*" /> <constructor-arg index="1" value="6379" /> </bean> <!-- jedis shard pool配置 --> <bean id="shardedJedisPool" class="redis.clients.jedis.ShardedJedisPool"> <constructor-arg index="0" ref="jedisPoolConfig" /> <constructor-arg index="1"> <list> <ref bean="jedis.shardInfo" /> </list> </constructor-arg> </bean>
参考:
http://*.com/questions/3047010/best-redis-library-for-java
https://github.com/xetorthio/johm
https://github.com/xetorthio/jedis/issues/closed#issue/76