摘要：配置以及緩存是一種數(shù)據(jù)庫(kù)，一種數(shù)據(jù)庫(kù)，一種數(shù)據(jù)庫(kù)如何緩存將想要緩存的數(shù)據(jù)添加到數(shù)據(jù)庫(kù)中基于內(nèi)存亦可持久化的數(shù)據(jù)庫(kù)，所以速度快配置啟動(dòng)緩存是默認(rèn)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(dòng)使用做緩存思路

是一種數(shù)據(jù)庫(kù)，一種數(shù)據(jù)庫(kù)，一種數(shù)據(jù)庫(kù)

如何緩存：將想要緩存的數(shù)據(jù)添加到 redis 數(shù)據(jù)庫(kù)中

redis：基于內(nèi)存亦可持久化的 Key-Value 數(shù)據(jù)庫(kù)，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(dòng) spring 緩存

keyGenerator bean 是默認(rèn)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(shí)候從 redis 中查詢，若查到了，就將數(shù)據(jù)返回；若沒(méi)查到，就從正在使用的數(shù)據(jù)庫(kù)查（比如 MySql，H2等），然后將數(shù)據(jù)放入 redis 數(shù)據(jù)庫(kù)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(cè)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(cè)試緩存市區(qū) 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(cè)試，比較不清晰