springboot中使用redis做数据缓存

SpringBoot缓存注解

@Cacheable一般用在查询

@CachePut一般用在新增

@CacheEvict一般用在更新或者删除

操作步骤

第一步

导入依赖

        <!-- 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>

第二步

写一个配置类，在配置类上写**@Configuration**、
@EnableCaching(开启缓存注解)这两个注解，继承CachingConfigurerSupport类

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;

@Configuration
@EnableCaching//开启缓存注解
public class RedisConfig extends CachingConfigurerSupport{
    
    
    //RedisTemplate模板
    @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;
    }

    //对缓存做管理
    @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;
    }
}

第三步

@Cacheable(value = “banner”,key=“‘selectIndexList’”)，value和key顺序前后都一样。key里面的值要加 单引号，不然会报错。

@Cacheable(value = "banner", key = "'selectIndexList'")
@Override
public List<CrmBanner> selectIndexList() {
    
    
List<CrmBanner> list = baseMapper.selectList(new
QueryWrapper<CrmBanner>().orderByDesc("sort"));
return list;
 }
@Override
public void pageBanner(Page<CrmBanner> pageParam, Object o) {
    
    
baseMapper.selectPage(pageParam,null);
 }
@Override
public CrmBanner getBannerById(String id) {
    
    
return baseMapper.selectById(id);
 }
@CacheEvict(value = "banner", allEntries=true)
@Override
public void saveBanner(CrmBanner banner) {
    
    
baseMapper.insert(banner);
 }

第四步

在application.properties文件中添加，如下模块

#Windows下写127.0.0.1，如果是Linux系统下则写自己对应的IP地址
spring.redis.host=127.0.0.1
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

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注意事项

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