SpringBoot2.x 整合Redis和使用Redis緩存

導入依賴

<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-redis -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
    <version>2.2.2.RELEASE</version>
</dependency>

以默認的方式(jdk序列化)存儲對象

配置序列化器，以json格式存儲

@Configuration
public class RedisConfig extends CachingConfigurerSupport {

    //配置Redistemplate
    @Bean
    public RedisTemplate<String, Object> redisTemplate(
            RedisConnectionFactory redisConnectionFactory)
            throws UnknownHostException {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);

        // 使用Jackson2JsonRedisSerialize 替換默認序列化
        Jackson2JsonRedisSerializer<Object> serializer = new Jackson2JsonRedisSerializer<>(Object.class);
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.activateDefaultTyping(objectMapper.getPolymorphicTypeValidator(),ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(objectMapper);

        // 設置value的序列化規則和 key的序列化規則
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(serializer);
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(serializer);
        template.afterPropertiesSet();

        return template;
    }

    //使用CacheManager緩存
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory factory) {
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

        //解決查詢緩存轉換異常的問題
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.activateDefaultTyping(om.getPolymorphicTypeValidator(),ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);

        // 配置序列化（解決亂碼的問題）,過期時間30秒
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofSeconds(1800000))
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
                .disableCachingNullValues();

        RedisCacheManager cacheManager = RedisCacheManager.builder(factory)
                .cacheDefaults(config)
                .build();
        return cacheManager;
    }
}

將Redis中的數據反序列化返回到前端頁面

編寫Controller

@RestController
public class EmployeeController {
    /**
     * 服務對象
     */
    @Resource
    private EmployeeService employeeService;

   //@Autowired
    //private RedisTemplate redisTemplate;
    /**
     * 通過主鍵查詢單條數據
     *
     * @param id 主鍵
     * @return 單條數據
     */
    @GetMapping("/emp/{id}")
    @Cacheable(cacheNames = {"emp"})  //使用緩存
    public Employee selectOne(@PathVariable("id") Integer id) {
        System.out.println("查詢了"+id+"號員工");
        return this.employeeService.queryById(id);
    }
}

進行訪問

看控制台輸出

我們可以看出進行了數據庫的查詢

清空控制台,我們再次進行訪問

說明確實走了Redis緩存

本篇隨筆參考[SpringBoot2.x整合redis和使用redis緩存](https://www.cnblogs.com/Neil-learning/p/12637711.html)