<parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.0.2.RELEASE</version><relativePath/>
</parent>

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

<!-- Java Persistence API, ORM 规范 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- 数据库连接 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- MySQL 驱动, 注意, 这个需要与 MySQL 版本对应 -->
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.12</version><scope>runtime</scope>
</dependency>

-- 测试数据库
CREATE DATABASE IF NOT EXISTS test;-- 城市信息表
CREATE TABLE IF NOT EXISTS `test`.`city_info` (`id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '自增 id',`city` varchar(128) NOT NULL DEFAULT '' COMMENT '城市名称',`longitude` bigint(20) NOT NULL DEFAULT '0' COMMENT '经度(100倍存储)',`latitude` bigint(20) NOT NULL DEFAULT '0' COMMENT '纬度(100倍存储)',PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT COMMENT='城市信息表';-- fake 测试数据
INSERT INTO `city_info` (`id`, `city`, `longitude`, `latitude`)
VALUES(1, '合肥', 11717, 3152),(2, '安庆', 11702, 3031),(3, '宿州', 11658, 3338);

/*** <h1>Redis 配置</h1>* 继承 CachingConfigurerSupport 重写 CacheManager 和 KeyGenerator* Created by Qinyi.*/
@EnableCaching      // 启用缓存功能, 默认不启用
@Configuration
public class RedisConfig extends CachingConfigurerSupport {private final RedisConnectionFactory redisConnectionFactory;@Autowiredpublic RedisConfig(RedisConnectionFactory redisConnectionFactory) {this.redisConnectionFactory = redisConnectionFactory;}/*** <h2>配置 CacheManager: 序列化方式、过期时间</h2>* */@Overridepublic CacheManager cacheManager() {// 初始化一个 RedisCacheWriter// RedisCacheWriter 提供了对 Redis 的 set、setnx、get 等命令的访问权限// 可以由多个缓存实现共享,并负责写/读来自 Redis 的二进制数据RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory);// 设置 CacheManager 的值序列化方式RedisSerializer<Object> jsonSerializer = new JdkSerializationRedisSerializer();RedisSerializationContext.SerializationPair<Object> pair = RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer);// 提供 Redis 的配置RedisCacheConfiguration defaultCacheConfig = RedisCacheConfiguration.defaultCacheConfig().serializeValuesWith(pair);// 设置默认超过期时间是 30 秒defaultCacheConfig.entryTtl(Duration.ofSeconds(30));// 初始化 RedisCacheManager 返回return new RedisCacheManager(redisCacheWriter, defaultCacheConfig);}/*** <h2>定义 key 生成器: 类名、方法名、参数列表</h2>* 自定义 KeyGenerator 的核心思想是保证 key 不会冲突* 默认的是 SimpleKeyGenerator, 它使用方法参数组合生成的一个 key, 这里存在一个问题:*  如果2个方法, 参数是一样的. 但执行逻辑不同, 那么将会导致执行第二个方法时命中第一个方法的缓存. 所以, 通常需要自定义.* */@Overridepublic KeyGenerator keyGenerator() {return (clazz, method, args) -> {StringBuilder sb = new StringBuilder();sb.append(clazz.getClass().getName()).append("#");sb.append(method.getName()).append("(");for (Object obj : args) {sb.append(obj.toString()).append(",");}sb.deleteCharAt(sb.length() - 1);sb.append(")");return sb.toString();};}
}

/*** <h1>城市信息实体</h1>* Created by Qinyi.*/
@Data
@NoArgsConstructor
@AllArgsConstructor
@Entity
@Table(name = "city_info")
public class CityInfo implements Serializable {/** 自增主键 */@Id@GeneratedValue(strategy = GenerationType.IDENTITY)@Column(name = "id", nullable = false)private Long id;/** 城市名称 */@Basic@Column(name = "city", nullable = false)private String city;/** 经度 */@Basic@Column(name = "longitude", nullable = false)private Long longitude;/** 纬度 */@Basic@Column(name = "latitude", nullable = false)private Long latitude;
}

/*** <h1>城市信息服务接口定义</h1>* Created by Qinyi.*/
public interface ICityInfoService {/*** <h2>根据 id 获取城市信息</h2>* @param id 记录 id* @return {@link CityInfo}* */CityInfo getCityInfoById(Long id);/*** <h2>更新城市信息</h2>* @param newObj 新的城市信息* @return {@link CityInfo}* */CityInfo updateCityInfo(CityInfo newObj);/*** <h2>根据 id 删除城市信息</h2>* @param id 记录 id* */void deleteCityInfoById(Long id);
}

/*** <h1>城市信息服务接口定义</h1>* Created by Qinyi.*/
@Slf4j
@Service
public class CityInfoServiceImpl implements ICityInfoService {/** CityInfo Dao */private final CityInfoRepository repository;@Autowiredpublic CityInfoServiceImpl(CityInfoRepository repository) {this.repository = repository;}/*** <h2>根据 id 获取城市信息</h2>* 如果不指定 key, 则会使用 KeyGenerator 来生成 key*  1. 如果指定了 key = "#id", redis 中的 key 是 city_info::1*  2. 如果使用自定义的 KeyGenerator(不指定 key), redis 中的 key 是:*      city_info::com.imooc.ad.service.impl.CityInfoServiceImpl#getCityInfoById(1)* */@Override@SuppressWarnings("all")@Cacheable(cacheNames = "city_info", key = "#id")
//    @Cacheable(cacheNames = "city_info")public CityInfo getCityInfoById(Long id) {log.info("get CityInfo by id: {}", id.toString());return repository.findById(id).get();}@Override@CachePut(cacheNames="city_info", key="#newObj.id")public CityInfo updateCityInfo(CityInfo newObj) {log.info("update CityInfo: {}", JSON.toJSONString(newObj));return repository.save(newObj);}@Override@CacheEvict(cacheNames = "city_info", key = "#id")public void deleteCityInfoById(Long id) {log.info("delete CityInfo by id: {}", id.toString());repository.deleteById(id);}
}

/*** <h1>Spring 声明式缓存测试用例</h1>* Created by Qinyi.*/
@RunWith(SpringRunner.class)
@SpringBootTest(classes = {Application.class}, webEnvironment = SpringBootTest.WebEnvironment.NONE)
public class CacheAnnotationTest {@Autowiredprivate ICityInfoService cityInfoService;/*** <h2>测试多次获取, 可以直接从缓存(Redis)中获取数据, 而不用查询数据库</h2>* */@Testpublic void testGetCityInfoById() {System.out.println(JSON.toJSONString(cityInfoService.getCityInfoById(1L)));}/*** <h2>测试更新缓存</h2>* */@Testpublic void testUpdateCityInfo() {System.out.println(JSON.toJSONString(cityInfoService.updateCityInfo(new CityInfo(1L, "合肥", 11717L, 3153L))));}/*** <h2>测试删除缓存</h2>* */@Testpublic void testDeleteCityInfoById() {cityInfoService.deleteCityInfoById(1L);}
}

127.0.0.1:6379> keys *
1) "city_info::1"
2) "city_info::com.imooc.ad.service.impl.CityInfoServiceImpl#getCityInfoById(1)"
127.0.0.1:6379> type city_info::1
string
127.0.0.1:6379> get city_info::1
"xacxedx00x05srx00x1ccom.imooc.ad.entity.CityInfoxe2/O>xd3xe6xeexc8x02x00x04Lx00x04citytx00x12Ljava/lang/String;Lx00x02idtx00x10Ljava/lang/Long;Lx00blatitudeqx00~x00x02Lx00tlongitudeqx00~x00x02xptx00x06xe5x90x88xe8x82xa5srx00x0ejava.lang.Long;x8bxe4x90xccx8f#xdfx02x00x01Jx00x05valuexrx00x10java.lang.Numberx86xacx95x1dx0bx94xe0x8bx02x00x00xpx00x00x00x00x00x00x00x01sqx00~x00x05x00x00x00x00x00x00x0cPsqx00~x00x05x00x00x00x00x00x00-xc5"
12