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。配置到类上面就是整个类下面的方法都是这个策略，

@Service
@CacheConfig(cacheManager = "redisCacheManager")
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {@Override@Cacheable(cacheNames = "userCache", key = "#id",sync=true)public User getUserById(Long id) {System.out.println("查询数据库了");return getById(id);}
}

配置到方法上，只对这个方法生效，这个策略

 @Override@Cacheable(cacheNames = "userCache", key = "#id",cacheManager = "cacheManager",sync=true)public User getUserById(Long id) {System.out.println("查询数据库了");return getById(id);}在这里插入代码片