Springboot with redis

spring boot redis

Springboot集成redis可以实现三个目标：

1. 缓存
2. 集中存储session
3. Pub/Sub消息队列

pom和properties配置

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

#spring.data.redis.repositories.enabled=false
spring.cache.type=redis
# 用redis存储session
spring.session.store-type=redis
spring.session.redis.namespace=myproject:session
spring.redis.host=localhost
spring.redis.port=6379
spring.redis.password=

启动类加@EnableCaching 启用缓存

@SpringBootApplication
@EnableCaching
public class Application {
  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}

使用缓存

在类和方法分别用@CacheConfig和@Cacheable、@CachePut、@CacheEvict等注解即可。

@Service
@CacheConfig(cacheNames = "myprojectcache:somentity")
public class SomentityService {
  @Cacheable(key="#id")
  public Somentity findById(Integer id) {
    //TODO:
  }
}

如果注解方式不能满足要求，可以注入@Resource cacheManager调用其方法处理缓存。

@Resource private CacheManager cacheManager;
//获取cache
cacheManager.getCache("myprojectcache:somentity").get/put/evict(...);

声明消息队列所需的@Bean messageListenerContainer

@Configuration
public class RedisConfig {
  @Bean
  public RedisMessageListenerContainer messageListenerContainer(RedisConnectionFactory connectionFactory) {
    RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    container.setConnectionFactory(connectionFactory);
    return container;
  }
}

定义MessageHandler

@Component
public interface RedisMessageHandler {
  public void handleMessage(String message);
}
@Slf4j
public class MyMessageHandler implements RedisMessageHandler {
  @Override
  public void handleMessage(String text) {
    log.debug(text);
  }
}

在合适的类里注入messageListenerContainer，实现添加消息监听频道的方法，以及发送消息的方法

@Autowired RedisMessageListenerContainer messageListenerContainer;
@Synchronized public void addMessageListener(String channel) {
  if (!exists(channel) {
    MessageListenerAdapter listener = new MessageListenerAdapter(new MyMessageHandler(channel));
    listener.afterPropertiesSet();
    messageListenerContainer.addMessageListener(listener, new ChannelTopic(channel));
  }
}
@Autowired private StringRedisTemplate stringRedisTemplate;
public void sendMsg(String channel, String message){
  stringRedisTemplate.convertAndSend(channel, message);
}

StringRedisTemplate的几个常见用法

ValueOperations<String, String> ops = stringRedisTemplate.opsForValue();
Long value = ops.increment(key) : ops.decrement(key);
Set<String> keys = stringRedisTemplate.keys(keyPrefix);
List<String> values = ops.multiGet(keys);
stringRedisTemplate.delete(key);
stringRedisTemplate.remame(key, newkey);