專案整合Redis快取主頁資料

阿新 • • 發佈：2021-06-26

1、在common模組新增依賴

由於redis快取是公共應用，所以我們把依賴與配置新增到了common模組下面，在common模組pom.xml下新增以下依賴

 <!-- redis -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-data-redis</artifactId>

        </dependency 
>

         <!--//spring2.X整合redis所需common-pool2-->

        <dependency>

            <groupId>org.apache.commons</groupId>

            <artifactId>commons-pool2</artifactId>

            <version>2.6.0</version>

        </dependency>

2、在service-base模組新增redis配置類

package com.wang.servicebase;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
 
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
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.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.time.Duration;

@EnableCaching
@Configuration
public class RedisConfig extends CachingConfigurerSupport {
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        template.setConnectionFactory(factory);
        //key序列化方式
        template.setKeySerializer(redisSerializer);
        //value序列化
        template.setValueSerializer(jackson2JsonRedisSerializer);
        //value hashmap序列化
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        return template;
    }

    @Bean
    public CacheManager cacheManager(RedisConnectionFactory factory) {
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        //解決查詢快取轉換異常的問題
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        // 配置序列化（解決亂碼的問題）,過期時間600秒
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofSeconds(600))
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
                .disableCachingNullValues();
        RedisCacheManager cacheManager = RedisCacheManager.builder(factory)
                .cacheDefaults(config)
                .build();
        return cacheManager;
    }

}

3.在service-cms模組配置檔案新增redis配置

#redis配置
spring.redis.host=8.140.124.212
spring.redis.port=6379
spring.redis.database=0
spring.redis.password=123456
spring.redis.timeout=1800000

spring.redis.lettuce.pool.max-active=20
spring.redis.lettuce.pool.max-wait=-1
#最大阻塞等待時間(負數表示沒限制)
spring.redis.lettuce.pool.max-idle=5
spring.redis.lettuce.pool.min-idle=0

4、在介面中新增redis快取

　　4.1在主啟動類上添加註解@EnableCaching

　　4.2修改CrmBannerServiceImpl實現類，新增redis快取註解

　　　　@Cacheable

屬性/方法名	解釋
value	快取名，必填，它指定了你的快取存放在哪塊名稱空間
cacheNames	與value差不多，二選一即可
key	可選屬性，可以使用SpEL標籤自定義快取的key

根據方法對其返回結果進行快取，下次請求時，如果快取存在，則直接讀取快取資料返回；如果快取不存在，則執行方法，並把返回的結果存入快取中。一般用在查詢方法上。

    @Override
    @Cacheable(key = "'selectIndexList'",value = "banner")
    public List<CrmBanner> selectAllBaners() {

        QueryWrapper<CrmBanner> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByDesc("id");
        queryWrapper.last("limit 2");
        List<CrmBanner> list = baseMapper.selectList(queryWrapper);
        return list;
    }