摘要：配置以及緩存是一種數據庫，一種數據庫，一種數據庫如何緩存將想要緩存的數據添加到數據庫中基于內存亦可持久化的數據庫，所以速度快配置啟動緩存是默認生成主鍵的方式是緩存管理器是的一種模板，還有一種模板是手動使用做緩存思路

是一種數據庫，一種數據庫，一種數據庫

如何緩存：將想要緩存的數據添加到 redis 數據庫中

redis：基于內存亦可持久化的 Key-Value 數據庫，所以速度快

    com.fasterxml.jackson.core
    jackson-databind
    2.4.1.3


    redis.clients
    jedis
    ${redis.version}


    org.springframework.data
    spring-data-redis
    ${spring.data.redis.version}


    org.springframework
    spring-context
    ${spring.version}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-data-redis")
    compile("com.fasterxml.jackson.core:jackson-databind:$jacksonVersion")
    compile("redis.clients:jedis:$redisVersion")
    ...
}

@EnableCaching
@Configuration
public class RedisConfig extends CachingConfigurerSupport {
    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return (target, method, params) -> {
            StringBuilder sb = new StringBuilder();
            sb.append(target.getClass().getName());
            sb.append(method.getName());
            for (Object obj : params) {
                sb.append(obj.toString());
            }
            return sb.toString();
        };
    }

    @Bean
    public CacheManager cacheManager(RedisTemplate redisTemplate) {
        return new RedisCacheManager(redisTemplate);
    }


    @Bean
    public RedisConnectionFactory redisCF() {
        JedisConnectionFactory cf = new JedisConnectionFactory();
        cf.setPassword("$2a$10$7e3cgzcCqwapf.TmEl1vi.b4ibSRxhqRjZKmRf9fV5b5u5L/CWaIa");
        return cf;
    }

    @Bean
    public StringRedisTemplate redisTemplate(RedisConnectionFactory cf) {
        StringRedisTemplate redis = new StringRedisTemplate(cf);
        Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(objectMapper);
        redis.setValueSerializer(serializer);
        redis.afterPropertiesSet();
        return redis;
    }

    ...
}

@EnableCaching 啟動 spring 緩存

keyGenerator bean 是默認生成主鍵的方式

cacheManager bean 是緩存管理器

StringRedisTemplate 是 spring-data-redis 的一種模板，還有一種模板是 RedisTemplate

public List findAll() {
    long provinces_redis_size = redis.opsForList().size("provinces").longValue();
    List redisProvinces = redis.opsForList().range("provinces", 0, provinces_redis_size);
    if(redisProvinces.size() != 0)
        return redisProvinces;

    List persistProvinces = repository.findAll();
    for(Provinces provinces : persistProvinces) {
        redis.opsForList().rightPush("provinces", provinces);
    }

    return persistProvinces;
}

思路就是查詢的時候從 redis 中查詢，若查到了，就將數據返回；若沒查到，就從正在使用的數據庫查（比如 MySql，H2等），然后將數據放入 redis 數據庫中

@Cacheable(value = "provincesCache", key = ""provinces"")
public List findAllWithSpringCache() {
    return repository.findAll();
}

@Cacheable(value = "citiesCache", key = "#provinceId")
public List findByProvinceId(String provinceId) {
    return repository.findByProvinceId(provinceId);
}

測試緩存省份 provinces

@SpringBootTest
@RunWith(SpringJUnit4ClassRunner.class)
public class ProvincesServiceTest {
    @Autowired
    private ProvincesService provincesService;

    @Autowired
    private RedisTemplate redis;

    @Autowired
    private StringRedisTemplate stringRedis;

    @After
    public void cleanUp() {
        redis.delete("provinces");
        stringRedis.delete("provinces");
        stringRedis.delete("provincesCache~keys");
    }

    @Test
    public void findAll() {
        List list = provincesService.findAll();
        Assert.assertEquals(list.size(), 34);
    }

    @Test
    public void findAllWithSpringCache() {
        List list = provincesService.findAllWithSpringCache();
        Assert.assertEquals(list.size(), 34);
    }
}

測試緩存市區 cities

@SpringBootTest
@RunWith(SpringJUnit4ClassRunner.class)
public class CitiesServiceTest {
    @Autowired
    private CitiesService citiesService;

    @Autowired
    private StringRedisTemplate stringRedis;

    @After
    public void cleanUp() {
        stringRedis.delete("440000");
    }

    @Test
    public void findByProvinceId() {
        List list = citiesService.findByProvinceId("440000");
        Assert.assertEquals(list.size(), 21);
    }
}

springmvc: https://git.oschina.net/seald...

springboot: https://git.oschina.net/seald...

建議看 springboot 的，springmvc 的加了挺多測試，比較不清晰