前言

大家在工作中可能会遇到这样的需求，即Redis读写分离，目的是为了压力分散化。下面我将为大家介绍借助AWS的ELB实现读写分离，以写主读从为例。

实现

引用库文件

<> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>2.6.2</version> </dependency>

方式一，借助切面

JedisPoolSelector

此类的目的是为读和写分别配置不同的注解，用来区分是主还是从。

package com.silence.spring.redis.readwriteseparation; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * Created by keysilence on 16/10/26. */ @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface JedisPoolSelector { String value(); }

JedisPoolAspect

此类的目的是针对主和从的注解，进行动态链接池调配，即主的使用主链接池，从的使用从连接池。

package com.silence.spring.redis.readwriteseparation; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; import org.aspectj.lang.reflect.MethodSignature; import org.springframework.beans.BeansException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import redis.clients.jedis.JedisPool; import javax.annotation.PostConstruct; import java.lang.reflect.Method; import java.util.Date; /** * Created by keysilence on 16/10/26. */ @Aspect public class JedisPoolAspect implements ApplicationContextAware { private ApplicationContext ctx; @PostConstruct public void init() { System.out.println("jedis pool aspectj started @" + new Date()); } @Pointcut("execution(* com.silence.spring.redis.readwriteseparation.util.*.*(..))") private void allMethod() { } @Before("allMethod()") public void before(JoinPoint point) { Object target = point.getTarget(); String method = point.getSignature().getName(); Class classz = target.getClass(); Class<?>[] parameterTypes = ((MethodSignature) point.getSignature()) .getMethod().getParameterTypes(); try { Method m = classz.getMethod(method, parameterTypes); if (m != null && m.isAnnotationPresent(JedisPoolSelector.class)) { JedisPoolSelector data = m .getAnnotation(JedisPoolSelector.class); JedisPool jedisPool = (JedisPool) ctx.getBean(data.value()); DynamicJedisPoolHolder.putJedisPool(jedisPool); } } catch (Exception e) { e.printStackTrace(); } } public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.ctx = applicationContext; } }

DynamicJedisPoolHolder

此类目的是存储当前使用的JedisPool，即上面类赋值后的结果保存。

package com.silence.spring.redis.readwriteseparation; import redis.clients.jedis.JedisPool; /** * Created by keysilence on 16/10/26. */ public class DynamicJedisPoolHolder { public static final ThreadLocal<JedisPool> holder = new ThreadLocal<JedisPool>(); public static void putJedisPool(JedisPool jedisPool) { holder.set(jedisPool); } public static JedisPool getJedisPool() { return holder.get(); } }

RedisUtils

此类目的是对Redis具体的调用，里面包含使用主还是从的方式调用。

package com.silence.spring.redis.readwriteseparation.util; import com.silence.spring.redis.readwriteseparation.DynamicJedisPoolHolder; import com.silence.spring.redis.readwriteseparation.JedisPoolSelector; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Created by keysilence on 16/10/26. */ public class RedisUtils { private static Logger logger = LoggerFactory.getLogger(RedisUtils.class); @JedisPoolSelector("master") public String setString(final String key, final String value) { String ret = DynamicJedisPoolHolder.getJedisPool().getResource().set(key, value); System.out.println("key:" + key + ",value:" + value + ",ret:" + ret); return ret; } @JedisPoolSelector("slave") public String get(final String key) { String ret = DynamicJedisPoolHolder.getJedisPool().getResource().get(key); System.out.println("key:" + key + ",ret:" + ret); return ret; } }

spring-datasource.xml

<"1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <bean id="poolConfig"> <> <property name="maxTotal" value="100"/> <> <property name="maxIdle" value="50"/> <> <property name="minIdle" value="20"/> <> <property name="maxWaitMillis" value="1000"/> <> <> <property name="testOnBorrow" value="true" /> <> <property name="testOnReturn" value="true" /> <> <property name="testWhileIdle" value="true" /> <> <property name="numTestsPerEvictionRun" value="10" /> <> <property name="timeBetweenEvictionRunsMillis" value="60000" /> <> <> </bean> <bean id="master"> <constructor-arg index="0" ref="poolConfig"/> <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/> <constructor-arg index="2" value="6379" type="int"/> </bean> <bean id="slave"> <constructor-arg index="0" ref="poolConfig"/> <> <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/> <constructor-arg index="2" value="6380" type="int"/> </bean> <bean id="redisUtils"> </bean> <bean id="jedisPoolAspect" /> <aop:aspectj-autoproxy proxy-target-class="true"/> </beans>

Test

package com.silence.spring.redis.readwriteseparation; import com.silence.spring.redis.readwriteseparation.util.RedisUtils; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * Created by keysilence on 16/10/26. */ public class Test { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-datasource.xml"); System.out.println(ctx); RedisUtils redisUtils = (RedisUtils) ctx.getBean("redisUtils"); redisUtils.setString("aaa", "111"); System.out.println(redisUtils.get("aaa")); } }

方式二，依赖注入

与方式一类似，但是需要写死具体使用主的池还是从的池，思路如下：

放弃注解的方式，直接将主和从的两个链接池注入到具体实现类中。

RedisUtils

package com.silence.spring.redis.readwriteseparation.util; import com.silence.spring.redis.readwriteseparation.DynamicJedisPoolHolder; import com.silence.spring.redis.readwriteseparation.JedisPoolSelector; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import redis.clients.jedis.JedisPool; /** * Created by keysilence on 16/10/26. */ public class RedisUtils { private static Logger logger = LoggerFactory.getLogger(RedisUtils.class); private JedisPool masterJedisPool; private JedisPool slaveJedisPool; public void setMasterJedisPool(JedisPool masterJedisPool) { this.masterJedisPool = masterJedisPool; } public void setSlaveJedisPool(JedisPool slaveJedisPool) { this.slaveJedisPool = slaveJedisPool; } public String setString(final String key, final String value) { String ret = masterJedisPool.getResource().set(key, value); System.out.println("key:" + key + ",value:" + value + ",ret:" + ret); return ret; } public String get(final String key) { String ret = slaveJedisPool.getResource().get(key); System.out.println("key:" + key + ",ret:" + ret); return ret; } }

spring-datasource.xml

<"1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <bean id="poolConfig"> <> <property name="maxTotal" value="100"/> <> <property name="maxIdle" value="50"/> <> <property name="minIdle" value="20"/> <> <property name="maxWaitMillis" value="1000"/> <> <> <property name="testOnBorrow" value="true" /> <> <property name="testOnReturn" value="true" /> <> <property name="testWhileIdle" value="true" /> <> <property name="numTestsPerEvictionRun" value="10" /> <> <property name="timeBetweenEvictionRunsMillis" value="60000" /> <> <> </bean> <bean id="masterJedisPool"> <constructor-arg index="0" ref="poolConfig"/> <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/> <constructor-arg index="2" value="6379" type="int"/> </bean> <bean id="slaveJedisPool"> <constructor-arg index="0" ref="poolConfig"/> <constructor-arg index="1" value="192.168.100.110" type="java.lang.String"/> <constructor-arg index="2" value="6380" type="int"/> </bean> <bean id="redisUtils"> <property name="masterJedisPool" ref="masterJedisPool"/> <property name="slaveJedisPool" ref="slaveJedisPool"/> </bean> </beans>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持查字典教程网。