spring缓存cache的使用
在spring配置文件中添加schema和spring对缓存注解的支持：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:cache="http://www.springframework.org/schema/cache"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/cache
http://www.springframework.org/schema/cache/spring-cache.xsd"
default-autowire="byName">
<!--缓存配置-->
<cache:annotation-driven/>在spring配置文件中加入缓存管理器：
<!-- generic cache manager -->
<bean id="cacheManager"
class="org.springframework.cache.support.SimpleCacheManager">
<property name="caches">
<set>
<bean class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"
p:name="hardwareCache"/>
<bean class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"
p:name="bannerCache"/>
</set>
</property>
</bean>
然后在代码的service的impl层加上如下注解即可把数据缓存起来：
@Cacheable(value="bannerCache")其中@Cacheable表示spring将缓存该方法获取到的数据，(缓存是基于key-value方式实现的)，key为该方法的参数，value为返回的数据，当你连续访问该方法时你会发现只有第一次会访问数据库. 其他次数只是查询缓存.减轻了数据库的压力.
当更新了数据库的数据，需要让缓存失效时，使用下面的注解：
这个注解表示让appCache缓存的所有数据都失效。
@CacheEvict(value = "appCache", allEntries = true)
springcache配置缓存存活时间
Spring Cache @Cacheable本身不支持key expiration的设置，以下代码可自定义实现Spring Cache的expiration，针对Redis、SpringBoot2.0。
直接上代码：
@Service
@Configuration
public class CustomCacheMng{
private Logger logger = LoggerFactory.getLogger(this.getClass());
// 指明自定义cacheManager的bean name
@Cacheable(value = "test",key = "'obj1'",cacheManager = "customCacheManager")
public User cache1(){
User user = new User().setId(1);
logger.info("1");
return user;
}
@Cacheable(value = "test",key = "'obj2'")
public User cache2(){
User user = new User().setId(1);
logger.info("2");
return user;
}
// 自定义的cacheManager，实现存活2天
@Bean(name = "customCacheManager")
public CacheManager cacheManager(
RedisTemplate<?, ?> redisTemplate) {
RedisCacheWriter writer = RedisCacheWriter.lockingRedisCacheWriter(redisTemplate.getConnectionFactory());
RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofDays(2));
return new RedisCacheManager(writer, config);
}
// 提供默认的cacheManager，应用于全局
@Bean
@Primary
public CacheManager defaultCacheManager(
RedisTemplate<?, ?> redisTemplate) {
RedisCacheWriter writer = RedisCacheWriter.lockingRedisCacheWriter(redisTemplate.getConnectionFactory());
RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig();
return new RedisCacheManager(writer, config);
}
}
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
