SpringCache基本操作

Spring Cache 是Spring 提供的一整套的缓存解决方案，它不是具体的缓存实现，它只提供一整套的接口和代码规范、配置、注解等，用于整合各种缓存方案，比如Redis、Caffeine、Guava Cache、Ehcache。使用注解方式替代原有硬编码方式缓存，语法更加简单优雅！

网上教程有点少，只记录一下使用方法

添加在公共模块

• 添加依赖

pom.xml

<!-- 缓存依赖 -->
<!--spring-cache-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- redis连接池-->
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
</dependency>

• 编写缓存配置

package org.ssm.config;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.jsontype.impl.LaissezFaireSubTypeValidator;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import org.springframework.context.annotation.Bean;
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.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;

import java.time.Duration;

/**
 * @author shaoshao
 * @Date 2022/11/29 20:59
 * @Description: 缓存配置类 放置配置的方法,子模板继承和复用
 */
public class CacheConfiguration {


    //配置缓存manager
    @Bean
    @Primary  //同类型,多个bean,默认生效! 默认缓存时间1小时!  可以选择!
    public RedisCacheManager cacheManagerHour(RedisConnectionFactory redisConnectionFactory) {

        RedisCacheConfiguration instanceConfig = instanceConfig(1 * 3600L);//缓存时间1小时

        //构建缓存对象
        return RedisCacheManager.builder(redisConnectionFactory)
                .cacheDefaults(instanceConfig)
                .transactionAware()
                .build();
    }

    //缓存一天配置
    @Bean
    public RedisCacheManager cacheManagerDay(RedisConnectionFactory redisConnectionFactory) {

        RedisCacheConfiguration instanceConfig = instanceConfig(24 * 3600L);//缓存时间1小时

        //构建缓存对象
        return RedisCacheManager.builder(redisConnectionFactory)
                .cacheDefaults(instanceConfig)
                .transactionAware()
                .build();
    }


    /**
     * 实例化具体的缓存配置!
     * 设置缓存方式JSON
     * 设置缓存时间 单位秒
     *
     * @param ttl
     * @return
     */
    private RedisCacheConfiguration instanceConfig(Long ttl) {

        //设置jackson序列化工具
        Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer
                = new Jackson2JsonRedisSerializer<Object>(Object.class);

        //常见jackson的对象映射器,并设置一些基本属性
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        objectMapper.registerModule(new JavaTimeModule());
        objectMapper.configure(MapperFeature.USE_ANNOTATIONS, false);
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        objectMapper.activateDefaultTyping(LaissezFaireSubTypeValidator.instance,
                ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);

        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);

        return RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofSeconds(ttl)) //设置缓存时间
                .disableCachingNullValues()
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer));
    }

}

application-cache.yml

spring:
  cache:
    type: redis
  redis:
    host: 192.168.174.131
    port: 6379
    jedis: # 设置Redis连接池
      pool:
        max-wait: 2000ms
        min-idle: 2
        max-idle: 8
        max-active: 10

调用模块

• 激活配置（这里是配置类在另一个模块，调用另一个模块）

application.yml

spring:
  profiles:
    active: cache

• 启动类添加注解

package org.ssm.product;

/**
 * @author shaoshao
 * @version 1.0
 * @date 2022/11/17 15:40
 */

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.context.annotation.Bean;
import org.ssm.clients.CategoryClient;
import org.ssm.clients.SearchClient;
import org.ssm.pojo.Category;

/**
 * projectName: b2c-cloud-store
 *
 * @author:
 * description: 启动类
 */
@SpringBootApplication
@MapperScan(basePackages = "org.ssm.product.mapper")
@EnableFeignClients(clients = {CategoryClient.class, SearchClient.class})
@EnableCaching
public class ProductApplication {

    public static void main(String[] args) {
        SpringApplication.run(ProductApplication.class,args);
    }


    /**
     * 新的分页插件,一缓和二缓遵循mybatis的规则,需要设置 MybatisConfiguration#useDeprecatedExecutor = false 避免缓存出现问题(该属性会在旧插件移除后一同移除)
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }



}

• 配置类继承公共模块的配置列

@Configuration
public class CarouselConfiguration extends CacheConfiguration {
}

控制层

package org.ssm.carousel.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.ssm.carousel.service.CarouselService;
import org.ssm.utils.R;

/**
 * @author shaoshao
 * @version 1.0
 * @date 2022/11/16 15:35
 */
@RestController
@RequestMapping("carousel")
public class CarouselController {

    @Autowired
    private CarouselService carouselService;
    @PostMapping("list")
    public R list() {
        return carouselService.list();
    }
}

实现类接口：CarouselService

public interface CarouselService {
    R list();
}

实现类：CarouselServiceImpl

package org.ssm.carousel.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import org.ssm.carousel.mapper.CarouselMapper;
import org.ssm.carousel.service.CarouselService;
import org.ssm.pojo.Carousel;
import org.ssm.utils.R;

import java.util.List;
import java.util.stream.Collectors;

/**
 * @author shaoshao
 * @version 1.0
 * @date 2022/11/16 15:46
 */
@Service
@Slf4j
public class CarouselServiceImpl implements CarouselService {

    @Autowired
    private CarouselMapper carouselMapper;

    @Cacheable(value = "list.carousel", key = "#root.methodName", cacheManager = "cacheManagerDay")
    @Override
    public R list() {
        QueryWrapper<Carousel> wrapper = new QueryWrapper<>();
        wrapper.orderByDesc("priority");
        List<Carousel> list = carouselMapper.selectList(wrapper);
        List<Carousel> collect = list.stream().limit(6).collect(Collectors.toList());
        log.info("CarouselServiceImpl.list业务结束,结果是: {}", R.ok(collect));
        return R.ok(collect);
    }
}

关于缓存的注解使用方法可以看注解的使用这篇博客cache模块

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