后端开发中缓存的作用以及基于Spring框架演示实现缓存

<!--        缓存的起步依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>

package com.example.demo;
 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
 
@SpringBootApplication
//开启缓存
@EnableCaching
public class DemoApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
 
}

@Override
@Cacheable(value="cacheSpace",key="#id")
public User getById(Integer id) {
    return userDao.selectById(id);
}