redis 配置以及缓存（javaconfig）

摘要：配置以及缓存是一种数据库，一种数据库，一种数据库如何缓存将想要缓存的数据添加到数据库中基于内存亦可持久化的数据库，所以速度快配置启动缓存是默认生成主键的方式是缓存管理器是的一种模板，还有一种模板是手动使用做缓存思路

是一种数据库，一种数据库，一种数据库

如何缓存：将想要缓存的数据添加到 redis 数据库中

redis：基于内存亦可持久化的 Key-Value 数据库，所以速度快

</>复制代码 
    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}

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

</>复制代码 
@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 启动 spring 缓存

keyGenerator bean 是默认生成主键的方式

cacheManager bean 是缓存管理器

StringRedisTemplate 是 spring-data-redis 的一种模板，还有一种模板是 RedisTemplate

</>复制代码 
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;
}

思路就是查询的时候从 redis 中查询，若查到了，就将数据返回；若没查到，就从正在使用的数据库查（比如 MySql，H2等），然后将数据放入 redis 数据库中

</>复制代码 
@Cacheable(value = "provincesCache", key = ""provinces"")
public List findAllWithSpringCache() {
    return repository.findAll();
}

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

测试缓存省份 provinces

</>复制代码 
@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);
    }
}

测试缓存市区 cities

</>复制代码 
@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...

建议看 springboot 的，springmvc 的加了挺多测试，比较不清晰