spring中的@Cacheable缓存
1. 使用方法
在方法上面加上注解@Cacheable,
@Override@Cacheable(cacheNames = "userCache", key = "#id")public User getUserById(Long id) {System.out.println("查询数据库了");return getById(id);}
如果你的项目中引入了,这个依赖会自动的使用reids作为缓存
<!-- pom.xml -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
2.切换策略
如果不想使用默认的缓存策略,那么可以再配置文件中制定相关的策略,
spring:cache:type: caffeine
如果是制定上面的策略需要下载相关的依赖否则可能会报错
<!-- caffeine缓存--><dependency><groupId>com.github.ben-manes.caffeine</groupId><artifactId>caffeine</artifactId></dependency>
3.工具类加@CacheConfig制定策略(推荐)
3.1 工具类
代码中制定了两种缓存的策略,1:Caffeine ,2:redis
制定1的换也是要引入相关的依赖文件的。
并且可以配置统一的key的过期时间等配置。
package com.jm.config;import java.time.Duration;
import java.util.concurrent.TimeUnit;
import com.github.benmanes.caffeine.cache.Caffeine;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.caffeine.CaffeineCacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;/*** 本地缓存配置*/
@Configuration
@EnableCaching
public class CacheConfig {@Value("${cache.capacity:100}")private Integer capacity;@Value("${cache.invalidSeconds:600}")private Long invalidSeconds;@Value("${cache.maxSize:1000}")private Long maxSize;@Bean("cacheManager")@Primarypublic CacheManager cacheManager() {CaffeineCacheManager cacheManager = new CaffeineCacheManager();cacheManager.setCaffeine(Caffeine.newBuilder().initialCapacity(capacity).expireAfterWrite(invalidSeconds, TimeUnit.SECONDS).maximumSize(maxSize));return cacheManager;}@Bean("redisCacheManager")public CacheManager redisCacheManager(RedisConnectionFactory connectionFactory) {RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig().serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer()))// 设置缓存过期时间为 invalidSeconds.entryTtl(Duration.ofSeconds(invalidSeconds));return RedisCacheManager.builder(connectionFactory).cacheDefaults(config).build();}
}
3.2使用方法
在类上加上@CacheConfig注解,并制定对应的缓存策略
@Service
@CacheConfig(cacheManager = "redisCacheManager")
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {@Override@Cacheable(cacheNames = "userCache", key = "#id")public User getUserById(Long id) {System.out.println("查询数据库了");return getById(id);}
}
备注说明
当然你也可以支持ehcahe,只有当你对数据持久化要求比较高的时候使用,当然我觉得90%的项目都不需要,我们只需要Caffeine就行了,他的性能比ehcache好太多了。