为什么要添加缓存?
加快显示商品 详情页的速度。
在哪里添加缓存?
前台系统? 还是 后台系统?
— 都加。
每个团队都应该为自己的系统功能负责任,保证其性能。
前台系统添加缓存
导入依赖
导入Spring和Jedis的整合文件
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
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-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<!-- 连接池的配置 -->
<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<property name="maxTotal" value="${redis.maxTotal}" />
</bean>
<!-- 分片式集群连接池 -->
<bean class="redis.clients.jedis.ShardedJedisPool">
<constructor-arg index="0" ref="jedisPoolConfig" />
<constructor-arg index="1">
<list>
<bean class="redis.clients.jedis.JedisShardInfo">
<constructor-arg index="0" value="${redis.node1.host}" />
<constructor-arg index="1" value="${redis.node1.port}" />
</bean>
</list>
</constructor-arg>
</bean>
</beans>
redis.maxTotal=100
redis.node1.host=127.0.0.1
redis.node1.port=6379
Spring配置读取外部文件:
Service中添加缓存逻辑
private static final String REDIS_KEY = "TAOTAO_WEB_ITEM_DETAIL_";
private static final Integer REDIS_TIME = 60 * 60 * 24;
public Item queryItemById(Long itemId) {
// 从缓存中命中
String key = REDIS_KEY + itemId;
try {
String cacheData = this.redisService.get(key);
if (StringUtils.isNotEmpty(cacheData)) {
return MAPPER.readValue(cacheData, Item.class);
}
} catch (Exception e1) {
e1.printStackTrace();
}
try {
String url = TAOTAO_MANAGE_URL + "/rest/item/" + itemId;
String jsonData = this.apiService.doGet(url);
if (StringUtils.isEmpty(jsonData)) {
return null;
}
try {
// 将数据写入到缓存中
this.redisService.set(key, jsonData, REDIS_TIME);
} catch (Exception e) {
e.printStackTrace();
}
return MAPPER.readValue(jsonData, Item.class);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}