添加依赖

由于redis缓存是公共应用，所以我们把依赖与配置添加到了common模块下面，在common模块pom.xml下添加以下依赖

<!-- redis -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

<!-- spring2.X集成redis所需common-pool2-->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.6.0</version>
</dependency>

配置

配置类

在service-base模块添加redis配置类，固定写法，粘贴即可

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 //开启缓存
@Configuration  //配置类
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);
        //解决查询缓存转换异常的问题
        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（解决乱码的问题）,过期时间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;
    }
}

使用redis模块配置

在使用到redis的模块的配置文件application.properties中添加redis配置

spring.redis.host=192.168.44.132
spring.redis.port=6379
spring.redis.database= 0
spring.redis.timeout=1800000

spring.redis.lettuce.pool.max-active=20
spring.redis.lettuce.pool.max-wait=-1
#最大阻塞等待时间(负数表示没限制)
spring.redis.lettuce.pool.max-idle=5
spring.redis.lettuce.pool.min-idle=0

linux中redis配置

1. 关闭防火墙

   #1:查看防火状态
   systemctl status firewalld
   service  iptables status
   
   #2:暂时关闭防火墙
   systemctl stop firewalld
   service  iptables stop
   
   #3:永久关闭防火墙
   systemctl disable firewalld
   chkconfig iptables off
   
   #4:重启防火墙
   systemctl enable firewalld
   service iptables restart  
   

2. redis配置文件

   1.注释掉bind 127.0.0.1
   
   2.修改protected-mode yes 为 protected-mode no
   

使用

由于首页数据变化不是很频繁，而且访问量相对较大，所以我们有必要把首页接口数据缓存到redis缓存中，减少数据库压力和提高访问速度改造service-cms模块首页banner接口，首页课程与讲师接口类似

springboot注解

缓存@Cacheable

根据方法对其返回结果进行缓存，下次再请求时，如果有缓存，则直接读取缓存数据返回；如果缓存不存在，则执行方法，并把返回的结果存入缓存中。一般用在查询方法上。

属性值如下：

缓存@CachePut

使用该注解标志的方法，每次都会执行，并将结果存入指定的缓存中。其他方法可以直接从响应的缓存中读取缓存数据，而不需要再去查询数据库。一般用在新增方法上。

属性值如下：

缓存@CacheEvict

使用该注解标志的方法，会清空指定的缓存。一般用在更新或者删除方法上

在service方法上使用注解

    @Cacheable(value = "banner", key = "‘selectIndexList‘")
    @Override
    public List<CrmBanner> selectAllBanner() {
        QueryWrapper<CrmBanner> wrapper = new QueryWrapper<>();
        wrapper.orderByDesc("id");
        wrapper.last("limit 2");
        List<CrmBanner> list = baseMapper.selectList(wrapper);
        return list;
    }

keys *查看redis是否存入

可以看到值已存入redis

谷粒 | 项目集成redis