简述

本文中，将改进数据服务。使用redis集群来提供缓存服务。

源代码

环境

IDE: IntelliJ IDEA
JDK: 1.8.0_u162
Framework: spring boot, dubbo
Cache: Redis
WebServer: Tomcat (本地端口8088)

开发

pom dependency

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

appliation.properties redis配置

通用

spring.redis.database=2
spring.redis.timeout=10000
spring.redis.pool.max-idle=8
spring.redis.pool.min-idle=1
spring.redis.pool.max-active=8
spring.redis.pool.max-wait=-1

单实例

1
2
3

spring.redis.host=127.0.0.1
spring.redis.port=6379
spring.redis.password=****

Sentinel集群

1 2	spring.redis.sentinel.master=mymaster spring.redis.sentinel.nodes=192.168.56.103:29000,192.168.56.103:29001,192.168.56.103:29002

配置类

RedisCacheConfig

package cn.icmyfuture.iarc.data.common;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.interceptor.KeyGenerator;
import org.springframework.context.annotation.Bean;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

public class RedisCacheConfig extends CachingConfigurerSupport {
    private static final Map<String, Long> cacheMap = new HashMap<String, Long>();

    public static void setCacheTime(String key, Long cacheTime){
        cacheMap.put(key, cacheTime);
    }

    @Bean
    public KeyGenerator keyGenerator() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append("v2:");
                sb.append(target.getClass().getName()+":");
                sb.append(method.getName()+":");
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };
    }

    @SuppressWarnings("rawtypes")
    @Bean
    public CacheManager cacheManager(RedisTemplate redisTemplate) {
        RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate);
        cacheManager.setExpires(cacheMap);
        return cacheManager;
    }

    @Bean
    public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) {
        StringRedisTemplate template = new StringRedisTemplate(factory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        om.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        template.setValueSerializer(jackson2JsonRedisSerializer);
        template.afterPropertiesSet();
        return template;
    }
}

CacheConfig

package cn.icmyfuture.iarc.data.config;

import cn.icmyfuture.iarc.data.common.RedisCacheConfig;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableCaching
public class CacheConfig extends RedisCacheConfig {
    public static final String getAllUsers = "getAllUsers";

    static {
        setCacheTime(getAllUsers, 180L);
    }
}

SpringBoot开启缓存

1 2	@EnableCaching public class DataApplication extends SpringBootServletInitializer

Service实现中，使用redis缓存

由于dubbo不支持使用注解@Cacheable，只能选择以下2种解决方式之一(本文使用第一种方式，对key的设置有更大的灵活性)

使用@Service注解，在代码中获取/设置缓存

不使用@Service注解，使用dubbo配置的方式来注册服务，同时开启缓存

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    UserDao userDao;

    @Autowired
    private CacheManager cacheManager;

    @Override
    public List<User> getAllUsers() {
        Cache cache = cacheManager.getCache(CacheConfig.getAllUsers);
        String key = String.format("%s", CacheConfig.getAllUsers);
        Cache.ValueWrapper wrapper = cache.get(key);
        List<User> users;
        if (wrapper == null) {
            users = userDao.getAllUsers();
            cache.put(key, users);
            return users;
        }
        return (List<User>) wrapper.get();
    }

调试

访问http://localhost:8002/user/getAllUsers来验证redis缓存的有效性
访问http://localhost:8002/druid/index.html来查看SQL监控以验证sql仅被执行了一次

部署

centos下配置好redis。maven工程根目录下执行命令mvn clean install，然后将iarc-data与iarc-service部署到tomcat中,访问http://localhost:8080/service/user/getAllUsers

架构之旅-集群与管理-数据-Redis

简述

源代码

环境

开发