mybatis整合redis步骤
1.添加redis相关依赖
redis与spring的整合依赖
log4j2配置:Log4j2 + Slf4j
jackson
2.spring + redis 集成实现缓存功能(与mybatis无关)
添加两个redis的配置文件,并将redis.properties和spring-redis.xml配置到spring-context.xml文件中
将redis缓存引入到mybatis中
注意事项:
1、spring多配置文件的引入方式
2、pom中对properties文件的编译
3、加一个spring-xxx.xml一定记得在spring-Context.xml导入
. redis常用类
1.1 Jedis
jedis就是集成了redis的一些命令操作,封装了redis的java客户端
1.2 JedisPoolConfig
Redis连接池
1.3 ShardedJedis
基于一致性哈希算法实现的分布式Redis集群客户端
实现 mybatis 的二级缓存,一般来说有如下两种方式:
1) 采用 mybatis 内置的 cache 机制。
2) 采用三方 cache 框架, 比如ehcache, oscache 等等.
具体步骤:
1 添加redis相关依赖
<!-- redis与spring的整合依赖 -->
<redis.version>2.9.0</redis.version>
<redis.spring.version>1.7.1.RELEASE</redis.spring.version>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>${redis.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-redis</artifactId>
<version>${redis.spring.version}</version>
</dependency>
版本冲突问题:
1. ClassNotFoundException : redis/client/util/geoUtils 说这个类找不到。
2. org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'redisTemplate' defined in class path resource [applicationContext.xml]
说创建 redisTemplate bean 对象时失败了。
redis.client 2.9.0 ---- spring-data-redis 1.7.1.RELEASE
redis.client 2.9.0 ---- spring-data-redis 1.7.2.RELEASE 这两个是可以使用的
.1.2 log4j2配置:Log4j2 + Slf4j (mybatis整合ehcache时导入了)
1.3 jackson
<!-- jackson -->
<jackson.version>2.9.3</jackson.version>
<!-- jackson -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
2.spring + redis 集成实现缓存功能(与mybatis无关)
2.1 添加两个redis的配置文件,并将redis.properties和spring-redis.xml配置到spring-context.xml文件中
redis.properties
redis.hostName=119.23.189.202
redis.port=6379
redis.password=123456
redis.timeout=10000
redis.maxIdle=300
redis.maxTotal=1000
redis.maxWaitMillis=1000
redis.minEvictableIdleTimeMillis=300000
redis.numTestsPerEvictionRun=1024
redis.timeBetweenEvictionRunsMillis=30000
redis.testOnBorrow=true
redis.testWhileIdle=true
spring-redis.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 1. 引入properties配置文件 -->
<!-- <context:property-placeholder location="classpath:redis.properties" />
--> <!-- 2. redis连接池配置-->
<bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
<!--最大空闲数-->
<property name="maxIdle" value="${redis.maxIdle}"/>
<!--连接池的最大数据库连接数 -->
<property name="maxTotal" value="${redis.maxTotal}"/>
<!--最大建立连接等待时间-->
<property name="maxWaitMillis" value="${redis.maxWaitMillis}"/>
<!--逐出连接的最小空闲时间 默认1800000毫秒(30分钟)-->
<property name="minEvictableIdleTimeMillis" value="${redis.minEvictableIdleTimeMillis}"/>
<!--每次逐出检查时 逐出的最大数目 如果为负数就是 : 1/abs(n), 默认3-->
<property name="numTestsPerEvictionRun" value="${redis.numTestsPerEvictionRun}"/>
<!--逐出扫描的时间间隔(毫秒) 如果为负数,则不运行逐出线程, 默认-1-->
<property name="timeBetweenEvictionRunsMillis" value="${redis.timeBetweenEvictionRunsMillis}"/>
<!--是否在从池中取出连接前进行检验,如果检验失败,则从池中去除连接并尝试取出另一个-->
<property name="testOnBorrow" value="${redis.testOnBorrow}"/>
<!--在空闲时检查有效性, 默认false -->
<property name="testWhileIdle" value="${redis.testWhileIdle}"/>
</bean>
<!-- 3. redis连接工厂 -->
<bean id="connectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
destroy-method="destroy">
<property name="poolConfig" ref="poolConfig"/>
<!--IP地址 -->
<property name="hostName" value="${redis.hostName}"/>
<!--端口号 -->
<property name="port" value="${redis.port}"/>
<!--如果Redis设置有密码 -->
<property name="password" value="${redis.password}"/>
<!--客户端超时时间单位是毫秒 -->
<property name="timeout" value="${redis.timeout}"/>
</bean>
<!-- 4. redis操作模板,使用该对象可以操作redis -->
<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
<property name="connectionFactory" ref="connectionFactory"/>
<!--如果不配置Serializer,那么存储的时候缺省使用String,如果用User类型存储,那么会提示错误User can't cast to String!! -->
<property name="keySerializer">
<bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>
</property>
<property name="valueSerializer">
<bean class="org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer"/>
</property>
<property name="hashKeySerializer">
<bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>
</property>
<property name="hashValueSerializer">
<bean class="org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer"/>
</property>
<!--开启事务 -->
<property name="enableTransactionSupport" value="true"/>
</bean>
<!-- 5.使用中间类解决RedisCache.RedisTemplate的静态注入,从而使MyBatis实现第三方缓存 -->
<bean id="redisCacheTransfer" class="com.zking.ssm.util.RedisCacheTransfer">
<property name="redisTemplate" ref="redisTemplate"/>
</bean>
</beans>
注1:将redis.properties导入到spring-context.xml文件中
spring中引入第二个属性文件会出现“找不到某个配置项”错误,这是因为spring只允许有一个<context:property-placeholder/>
<!--引入一个属性文件的写法-->
<context:property-placeholder ignore-unresolvable="true" location="classpath:jdbc.properties" />
<!--引入两个或多个属性文件的写法-->
<context:property-placeholder ignore-unresolvable="true" location="classpath:jdbc.properties,classpath:redis.properties" />
注2:通过import标签将spring-redis.xml导入到spring-context.xml文件中
<!--导入redis配置-->
<import resource="spring-redis.xml"/>
<!--1. 引入外部多文件方式 -->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<property name="ignoreResourceNotFound" value="true" />
<property name="locations">
<list>
<value>classpath:jdbc.properties</value>
<value>classpath:redis.properties</value>
</list>
</property>
</bean>
<?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">
<!-- 1. 引入外部多文件方式-->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
<property name="ignoreResourceNotFound" value="true" />
<property name="locations">
<list>
<value>classpath:jdbc.properties</value>
<value>classpath:redis.properties</value>
</list>
</property>
</bean>
<import resource="spring-mybatis.xml"></import>
<import resource="mybatis-ehcache.xml"></import>
<import resource="spring-redis.xml"></import>
</beans>
pom.xml中改一下
2.2 将redis缓存引入到mybatis中
1 创建mybatis的自定义缓存类“RedisCache”,必须实现org.apache.ibatis.cache.Cache接口
RedisCache.java (对比 mybatis整合echcache 相当于echcache的第四步 ,在XxxMapper.xml中配置cache )
package com.zking.ssm.util;
import org.apache.ibatis.cache.Cache;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
public class RedisCache implements Cache //实现类
{
private static final Logger logger = LoggerFactory.getLogger(RedisCache.class);
private static RedisTemplate<String,Object> redisTemplate;
private final String id;
/**
* The {@code ReadWriteLock}.
*/
private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
@Override
public ReadWriteLock getReadWriteLock()
{
return this.readWriteLock;
}
public static void setRedisTemplate(RedisTemplate redisTemplate) {
RedisCache.redisTemplate = redisTemplate;
}
public RedisCache(final String id) {
if (id == null) {
throw new IllegalArgumentException("Cache instances require an ID");
}
logger.debug("MybatisRedisCache:id=" + id);
this.id = id;
}
@Override
public String getId() {
return this.id;
}
@Override
public void putObject(Object key, Object value) {
try{
logger.info(">>>>>>>>>>>>>>>>>>>>>>>>putObject: key="+key+",value="+value);
if(null!=value)
redisTemplate.opsForValue().set(key.toString(),value,2, TimeUnit.DAYS);
}catch (Exception e){
e.printStackTrace();
logger.error("redis保存数据异常!");
}
}
@Override
public Object getObject(Object key) {
try{
logger.info(">>>>>>>>>>>>>>>>>>>>>>>>getObject: key="+key);
if(null!=key)
return redisTemplate.opsForValue().get(key.toString());
}catch (Exception e){
e.printStackTrace();
logger.error("redis获取数据异常!");
}
return null;
}
@Override
public Object removeObject(Object key) {
try{
if(null!=key)
return redisTemplate.expire(key.toString(),1,TimeUnit.DAYS);
}catch (Exception e){
e.printStackTrace();
logger.error("redis获取数据异常!");
}
return null;
}
@Override
public void clear() {
Long size=redisTemplate.execute(new RedisCallback<Long>() {
@Override
public Long doInRedis(RedisConnection redisConnection) throws DataAccessException {
Long size = redisConnection.dbSize();
//连接清除数据
redisConnection.flushDb();
redisConnection.flushAll();
return size;
}
});
logger.info(">>>>>>>>>>>>>>>>>>>>>>>>clear: 清除了" + size + "个对象");
}
@Override
public int getSize() {
Long size = redisTemplate.execute(new RedisCallback<Long>() {
@Override
public Long doInRedis(RedisConnection connection)
throws DataAccessException {
return connection.dbSize();
}
});
return size.intValue();
}
}
2 静态注入中间类“RedisCacheTransfer”,解决RedisCache中RedisTemplate的静态注入,从而使MyBatis实现第三方缓存
RedisCacheTransfer.java
package com.zking.ssm.util;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
public class RedisCacheTransfer {
@Autowired
public void setRedisTemplate(RedisTemplate redisTemplate) {
RedisCache.setRedisTemplate(redisTemplate);
}
}
2.3 spring与mybatis整合文件中开发二级缓存(整合echcache时加了)
加入spring-mybatis.xml
<!--设置mybaits对缓存的支持-->
<property name="configurationProperties">
<props>
<!-- 全局映射器启用缓存 *主要将此属性设置完成即可-->
<prop key="cacheEnabled">true</prop>
<!-- 查询时,关闭关联对象即时加载以提高性能 -->
<prop key="lazyLoadingEnabled">false</prop>
<!-- 设置关联对象加载的形态,此处为按需加载字段(加载字段由SQL指 定),不会加载关联表的所有字段,以提高性能 -->
<prop key="aggressiveLazyLoading">true</prop>
</props>
</property>
2.4 在XxxMapper.xml中添加自定义cache功能
<cache
type="com.zking.zf.redis.RedisCache"
eviction="LRU"
flushInterval="6000000"
size="1024"
readOnly="false"
/>
type:指定redis的二级缓存类的全路径名
eviction:二级缓存算法(FIFO/LRU/SOFT/WEAK)
flushInterval:刷新间隔,间隔多长时间清空缓存,被动触发非定时器轮询
size:缓存大小。每个缓存可以存储 1024 个列表或对象的引用
readOnly:缓存将作为“读/写”缓存,意味着获取的对象不是共享的且对调用者是安全的。不会有其它的调用者或线程潜在修改。
再自己测试一波就ok了