java web redis使用(二)

上篇中已经安装好redis，然后下面就说怎么在java web中用客户端来使用regis

使用jedis java客户端 

一：一个简单的示例代码:

public   static   void  main(String[] args) {
    Jedis jedis = new  Jedis( "147.151.240.234" , 6379 );
    jedis.set("foo" ,  "bar" );
    String value = jedis.get("foo" );
    System.out.println(value);
}

 

二：spring中配置 ：

首先，在项目中引入jeids的jar包。   

<!-- java readis客户端 -->
< dependency >
    < groupId > redis.clients </ groupId >
    < artifactId > jedis </ artifactId >
    < version > 2.0.0 </ version >
</ dependency >

其次，在spring配置文件中添加配置（也可以直接new出这些对象，一样的） 

<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
    <property name="maxActive"  value="50" />
    <property name="maxIdle" value="10" />
    <property name="maxWait" value="1000" />
    <property name="testOnBorrow"  value="true"/>
</bean>

<bean id="jedis.shardInfo" class="redis.clients.jedis.JedisShardInfo">
    <constructor-arg index="0" value="这里填你的reids服务器ip" />
    <constructor-arg index="1" value="6379" />
</bean>

<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>

 

最后，调用的时候

 

ShardedJedis jedis =  shardedJedisPool.getResource();
   jedis.get(key); //从redis服务器获取值
   jedis.set(key, value); //将值保存到redis服务器

 

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>

 

 

最近初次尝试使用redis，java客户端采用的jedis，写了几个简单的类满足基本的服务器配置，以及客户端对象的使用等。

客户端对象的创建

package  jediscache.common;

import  redis.clients.jedis.Jedis;
import  redis.clients.jedis.JedisPool;
import  redis.clients.jedis.JedisPoolConfig;
import  redis.clients.jedis.Protocol;

public   class  JedisFactory {

    private  JedisPoolConfig jedisPoolConfig;

    private  JedisPool jedisPool;

    public  JedisFactory(JedisPoolConfig jedisPoolConfig) {
        super ();
        this .jedisPoolConfig = jedisPoolConfig;
    }

    public  Jedis getJedisInstance(String host) {
        return  getJedisPool(host, Protocol.DEFAULT_PORT).getResource();
    }

    public  Jedis getJedisInstance(String host,  int  port) {
        return  getJedisPool(host, port).getResource();
    }

    public  JedisPool getJedisPool(String host) {
        return  getJedisPool(host, Protocol.DEFAULT_PORT);
    }

    public  JedisPool getJedisPool(String host,  int  port) {
        if  (jedisPool ==  null ) {
            jedisPool = new  JedisPool(jedisPoolConfig, host, port);
        }
        return  jedisPool;
    }

    /**
     * 配合使用getJedisInstance方法后将jedis对象释放回连接池中
     *
     * @param jedis 使用完毕的Jedis对象
     * @return true 释放成功；否则返回false
     */
    public   boolean  release(Jedis jedis) {
        if  (jedisPool !=  null  && jedis !=  null ) {
            jedisPool.returnResource(jedis);
            return   true ;
        }
        return   false ;
    }

}

 

使用客户端对象

public   void  testLpush() {
    JedisFactory factory = new  JedisFactory( new  JedisPoolConfig());
    Jedis jedis = factory.getJedisInstance("localhost" );

    try  {
        String word = "word" ;
        jedis.lpush(word, "first" );
        jedis.lpush(word, "second" );
        jedis.lpush(word, "three" );
        System.out.println("word : "  + jedis.lrange(word,  0 , - 1 ));
    } finally  {
        factory.release(jedis);
    }
}