Shrio+Redis实现tomcat集群session共享
一、背景
当我们使用了nginx做项目集群以后，就会出现一个很严重的问题亟待解决，那就是：tomcat集群之间如何实现session共享的问题，如果这个问题不解决，就会出现登陆过后再次请求资源依旧需要登陆的问题。这篇文章我们就解决这个问题。
二、实现步骤
说明：本篇是在spring+shiro集成的基础上进行改进的，如果不知道spring和shiro怎么集成，请移步：spring集成shiro做登陆认证
1.在pom.xml中添加shiro-redis和jedis的依赖
<dependency>
<groupId>org.crazycake</groupId>
<artifactId>shiro-redis</artifactId>
<version>2.4.2.1-RELEASE</version>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.7.2</version>
</dependency>
2.首先我们需要对redis进行集成，在resources下新建config.properties
#redis pool config
redis.pool.maxActive=200
redis.pool.maxIdle=100
redis.pool.maxWait=100
redis.pool.testOnBorrow=true
#redis config
redis.host=192.168.85.129
redis.port=6379
redis.timeout=2000
redis.password=123456
redis.dbindex=8
redis.default.expire=1800000
3.在resources/spring文件夹下新建spring-redis.xml来集成redis操作客户端
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<description>Redis configuration</description>
<bean id="redisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<property name="maxTotal" value="${redis.pool.maxActive}"/>
<property name="maxIdle" value="${redis.pool.maxIdle}"/>
<property name="maxWaitMillis" value="${redis.pool.maxWait}"/>
<property name="testOnBorrow" value="${redis.pool.testOnBorrow}"/>
</bean>
<bean id="jedisPool" class="redis.clients.jedis.JedisPool" destroy-method="destroy">
<constructor-arg ref="redisPoolConfig"/>
<constructor-arg value="${redis.host}"/>
<constructor-arg type="int" value="${redis.port}"/>
<constructor-arg type="int" value="${redis.timeout}"/>
<constructor-arg type="java.lang.String" value="${redis.password}"/>
<constructor-arg type="int" value="${redis.dbindex}"/>
</bean>
<bean id="redisClient" class="com.hafiz.www.redis.RedisClient">
<constructor-arg name="jedisPool" ref="jedisPool"/>
<property name="expire" value="${redis.default.expire}"/>
</bean>
</beans>
4.添加redisClient.java作为访问redis的客户端
package com.hafiz.www.redis;
import org.crazycake.shiro.RedisManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import java.util.Set;
/**
* Desc: Jedis 操作客户端
* Created by hafiz.zhang on 2017/7/21.
*/
public class RedisClient extends RedisManager{
private static final Logger LOGGER = LoggerFactory.getLogger(RedisClient.class);
private static JedisPool jedisPool = null;
public RedisClient(JedisPool jedisPool) {
this.jedisPool = jedisPool;
}
public void init() {
super.init();
}
@Override
public byte[] get(byte[] key) {
Jedis jedis = jedisPool.getResource();
byte[] value;
try {
value = jedis.get(key);
} catch (Exception e) {
LOGGER.error("redis key:{} get value occur exception", new String(key));
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
return value;
}
@Override
public byte[] set(byte[] key, byte[] value) {
Jedis jedis = jedisPool.getResource();
try {
jedis.set(key, value);
Integer expire = getExpire();
if(expire != 0) {
jedis.expire(key, expire);
}
} catch (Exception e) {
LOGGER.error("redis key:{} set value:{} occur exception", new String(key), new String(value));
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
return value;
}
@Override
public byte[] set(byte[] key, byte[] value, int expire) {
Jedis jedis = jedisPool.getResource();
try {
jedis.set(key, value);
if(expire != 0) {
jedis.expire(key, expire);
}
} catch (Exception e) {
LOGGER.error("redis key:{} set value:{} in expire:{} occur exception", new String(key), new String(value), expire);
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
return value;
}
@Override
public void del(byte[] key) {
Jedis jedis = jedisPool.getResource();
try {
jedis.del(key);
} catch (Exception e) {
LOGGER.error("redis key:{} del value occur exception", new String(key));
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
}
@Override
public void flushDB() {
Jedis jedis = jedisPool.getResource();
try {
jedis.flushDB();
} catch (Exception e) {
LOGGER.error("redis flushDB occur exception");
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
}
@Override
public Long dbSize() {
Long dbSize = Long.valueOf(0L);
Jedis jedis = jedisPool.getResource();
try {
dbSize = jedis.dbSize();
} catch (Exception e) {
LOGGER.error("redis get dbSize occur exception");
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
return dbSize;
}
@Override
public Set<byte[]> keys(String pattern) {
Set keys = null;
Jedis jedis = jedisPool.getResource();
try {
keys = jedis.keys(pattern.getBytes());
} catch (Exception e) {
LOGGER.error("redis get keys in pattern:{} occur exception", pattern);
throw new RuntimeException("redis operation error:", e);
} finally {
jedis.close();
}
return keys;
}
}
5.接着，我们对spring-shiro.xml做如下修改(红色标记的部分)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util.xsd">
<description>Shiro Configuration</description>
<!--shiro-redis redisCacheManager-->
<bean id="redisCacheManager" class="org.crazycake.shiro.RedisCacheManager">
<property name="keyPrefix" value="shiro_redis_session:"/>
<property name="redisManager" ref="redisClient"/>
</bean>
<!--custom myself realm-->
<bean id="customRealm" class="com.hafiz.www.shiro.CustomRealm">
<property name="cacheManager" ref="redisCacheManager"/>
</bean>
<!--redisSessionDAO-->
<bean id="redisSessionDAO" class="org.apache.shiro.session.mgt.eis.EnterpriseCacheSessionDAO"></bean>
<!--simpleCookie,不定义在集群环境下会出现There is no session with id ....-->
<bean id="simpleCookie" class="org.apache.shiro.web.servlet.SimpleCookie">
<constructor-arg name="name" value="custom.session"/>
<property name="path" value="/"/>
</bean>
<!--sessionManager-->
<bean id="sessionManager" class="org.apache.shiro.web.session.mgt.DefaultWebSessionManager">
<property name="sessionDAO" ref="redisSessionDAO"/>
<property name="sessionIdCookie" ref="simpleCookie"/>
</bean>
<!--Shiro`s main business-tier object for web-enable applications-->
<bean id="securityManager" class="org.apache.shiro.web.mgt.DefaultWebSecurityManager">
<property name="realm" ref="customRealm"/>
<property name="cacheManager" ref="redisCacheManager"/>
<property name="sessionManager" ref="sessionManager"/>
</bean>
<!--shiro filter-->
<bean id="shiroFilter" class="org.apache.shiro.spring.web.ShiroFilterFactoryBean">
<property name="securityManager" ref="securityManager"/>
<property name="loginUrl" value="/login.html"/>
<property name="successUrl" value="/index.html"/>
<property name="unauthorizedUrl" value="/unauthorized.html"/>
<property name="filters">
<util:map>
<entry key="auth">
<bean class="com.hafiz.www.filter.AuthorizeFilter"/>
</entry>
</util:map>
</property>
<property name="filterChainDefinitions">
<value>
/login.json = anon
/logout.json = anon
/js/** = anon
/ = authc
/** = auth
</value>
</property>
</bean>
</beans>
6.spring.xml做如下修改
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<context:property-placeholder location="classpath:config.properties,classpath:jdbc.properties"/>
<import resource="spring-*.xml"/>
</beans>
到此我们就完了shiro+redis实现session共享的问题，其实也很简单，其中的实现逻辑也很简单，就是shiro的拦截器会首先去redis里面获取session,作为当本次请求的session.
其他代码以及简单测试代码不再贴出，给出github地址：https://github.com/hafizzhang/shiro-session-cluster.git
三、总结
通过本文，我们就完成了spring+shiro+redis实现集群session共享的问题，经过亲测可行。但有一点遗憾的地方，就是每次请求至少会有8次redis的读操作，一次写操作，这个问题还没有找到很好的解决办法，本地使用ehcahe也不太现实，因为涉及到本地缓存和redis缓存同步的问题，如果你有好的办法，欢迎讨论交流学习！
