Spring Cache

Spring Cache

Spring Cache是一个框架，实现了基于注解的缓存功能，只需简单加一个注解，就能实现缓存功能

底层提供了抽象，可以切换不同的缓存实现，例如：EHCache,Caffeine,Redis

maven坐标

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-cache</artifactId>
    <version>2.7.3</version>
</dependency>

注解

注解	说明
@EnableCaching	开启缓存注解功能，通常加在启动类上
@Cacheable	在方法执行前先查询缓存中是否有数据，如果有数据，则直接返回缓存数据；如果没有缓存数据，调用方法并将方法返回值放到缓存中
@CachePut	将方法的返回值放到缓存中
@CacheEvict	将一条或多条数据从缓存中删除

CachePut样例

//key生成样式为:userChache::id
//@CachePut(cacheNames= "userCache",key = "#result.id")
//@CachePut(cacheNames= "userCache",key = "#p0.id")
//@CachePut(cacheNames= "userCache",key = "#a0.id")
//@CachePut(cacheNames= "userCache",key = "#root.args[0].id")
//@CachePut(cacheNames= "userCache",key = "#user.id")
public User save(@RequestBody User user){
    userMapper.insert(user);
    return user;
}

Cacheable样例

@Cacheable("cacheNames= "userCache",key = "#id"")//此处只能用形参id
public User getById(Long id){
    User user = userMapper.getById(id);
    return user;
}

CacheEvict样例

//方法执行完才删除缓存数据，此方法只能删除一条数据
@Cacheable("cacheNames= "userCache",key = "#id"")
public void deleteById(Long id){
    userMapper.deleteById(id);
}
//此方法能删除所有数据
@Cacheable("cacheNames= "userCache",allEntries = true)
public void deleteById(){
    userMapper.deleteAll();
}