springboot+springcache+r

一. spring cache

对于缓存，可以使用的框架太多，如reids,caffeine,ehcache等等，各有各自的优势。如果我们要想使用缓存，就得与这些框架耦合，为了避免这种情况，spring cache就利用AOP，实现基于注解的缓存功能，并进行合理的抽象，使业务代码不用担心底层使用了什么缓存框架。

二. 编码

1. maven依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
</dependencies>
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2. application.yml配置文件

spring:
  redis:
    lettuce:
      pool:
        max-active: 8 # 连接池最大连接数
        max-idle: 8 # 连接池最大空闲连接数
        min-idle: 0 # 连接池最小空闲连接数
        max-wait: -1ms # 连接池最大阻塞等待时间，负值表示没有限制
    host: localhost
    port: 6379
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3. CacheConfig配置类

/**
 * @Description: 缓存配置
 * @Author: songrenwei
 * @Date: 2020/12/11/00:00
 */
@Configuration
@EnableCaching
public class CacheConfig {

    @Bean
    public CacheManager cacheManager(RedisConnectionFactory connectionFactory) {
        RedisSerializer<String> stringRedisSerializer = new StringRedisSerializer();
        //default信息缓存配置
        RedisCacheConfiguration default1h = RedisCacheConfiguration.defaultCacheConfig()
                        // 设置过期时间
                        .entryTtl(Duration.ofHours(1))
                        // String的方式序列化key
                        .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(stringRedisSerializer))
                        // jackson的方式序列化value
                        .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer()))
                        // 空值不缓存
                        .disableCachingNullValues()
                        // 设置缓存名称前缀
                        .prefixCacheNameWith("default_1h:");
        RedisCacheConfiguration m30 = RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofMinutes(30)).serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(stringRedisSerializer)).serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer())).disableCachingNullValues().prefixCacheNameWith("srw_");
        RedisCacheConfiguration d30 = RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofDays(30)).serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(stringRedisSerializer)).serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer())).disableCachingNullValues().prefixCacheNameWith("srw_");
        RedisCacheConfiguration h24 = RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofHours(24)).serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(stringRedisSerializer)).serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer())).disableCachingNullValues().prefixCacheNameWith("srw_");
        RedisCacheConfiguration s60 = RedisCacheConfiguration.defaultCacheConfig().entryTtl(Duration.ofSeconds(60)).serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(stringRedisSerializer)).serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer())).disableCachingNullValues().prefixCacheNameWith("srw_");

        Map<String, RedisCacheConfiguration> redisCacheConfigurationMap = new LinkedHashMap<String, RedisCacheConfiguration>(8) {
            private static final long serialVersionUID = 2474073019770319870L;
            {
                put("60s", s60);
                put("30m", m30);
                put("24h", h24);
                put("30d", d30);
                put("default", default1h);
            }
        };

        return new RedisCacheManager(RedisCacheWriter.nonLockingRedisCacheWriter(connectionFactory), default1h, redisCacheConfigurationMap);
    }

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);
        RedisSerializer<Object> jackson2JsonRedisSerializer = jsonSerializer();
        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        // key采用String的序列化方式
        template.setKeySerializer(stringRedisSerializer);
        // hash的key也采用String的序列化方式
        template.setHashKeySerializer(stringRedisSerializer);
        // value序列化方式采用jackson
        template.setValueSerializer(jackson2JsonRedisSerializer);
        // hash的value序列化方式采用jackson
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        template.afterPropertiesSet();
        return template;
    }

    private RedisSerializer<Object> jsonSerializer() {
        Jackson2JsonRedisSerializer<Object> 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.activateDefaultTyping(LaissezFaireSubTypeValidator.instance , ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        return jackson2JsonRedisSerializer;
    }

}
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4. 测试

4.1 controller

@Slf4j
@RestController
@RequestMapping("/user")
@RequiredArgsConstructor
public class UserController {

    private final UserService userService;

    @GetMapping("/query/{id}")
    public JsonResult<?> query(@PathVariable("id") Long id) {
        return JsonResult.successResponse(userService.query(id));
    }
}
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4.2 service

@Slf4j
@Service
@RequiredArgsConstructor
public class UserServiceImpl implements UserService {

    private final UserMapper userMapper;

    @Cacheable(value = "30m", key = "#id", unless = "#result == null")
    @Override
    public User query(Long id) {
        return userMapper.selectById(id);
    }
}
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4.3 测试结果

调用前先刷新下redis, 如下没有对应的key

postman调用接口

成功响应，查看日志

刷新redis

redis中已经存储了key, 以及缓存有效期
再调下接口，查看日志，未显示日志，说明已经走了redis。