（一） 缓存
1、 内存缓存的利与弊
可以使用google guava cache或则caffie，作为内存缓存性能之王。但是只能基于内存，不具备分布式的能力，并且想让内存缓存失效再外部控制比较难实现。如果需要实现，则通过接口或则其他方式进行内存缓存的失效管理。例如通过MQ等消息中间件，维护开发较难。
2、 分布式缓存redis
a) 单机
b) 集群模式
（一） Redis 6.X Sentinel 哨兵集群搭建https://mp.weixin.qq.com/s/iy2y135EirDig87NZ-Xeqw
c) 客户端
（一） 可视化工具AnotherRedisDesktopManager
https://mp.weixin.qq.com/s/_YgvMn1GKCwrJkB9-KQxJg
d) 分布式锁 Redission
（一） https://mp.weixin.qq.com/s/CbnPRfvq4m1sqo2uKI6qQw
e) Springboot整合实现
package com.manlitech.cloudboot.basebootconfig.redis;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.manlitech.cloudboot.common.enums.ResultEnums;
import com.manlitech.cloudboot.basebootconfig.exception.MyException;
import io.lettuce.core.ReadFrom;
import io.lettuce.core.cluster.ClusterClientOptions;
import io.lettuce.core.cluster.ClusterTopologyRefreshOptions;
import org.joda.time.DateTime;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.data.redis.RedisProperties;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisClusterConfiguration;
import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceClientConfiguration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import java.time.Duration;
/**
* redis集群配置
* @author shensg
* @date 2019/3/21
*
* 增加
* @EnableCaching
* extends CachingConfigurerSupport
* 两处即可实现@Cacheable @CachePut @CacheEvict 使用
*/
@Configuration
public class RedisConfiguration {
@Autowired
private RedisProperties redisProperties;
@Value("${redis.maxRedirects:3}")
private int maxRedirects;
@Value("${redis.refreshTime:5}")
private int refreshTime;
@Bean
public LettuceConnectionFactory redisConnectionFactory() {
//单机版
if(redisProperties.getCluster() == null) {
RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
redisStandaloneConfiguration.setDatabase(redisProperties.getDatabase());
redisStandaloneConfiguration.setHostName(redisProperties.getHost());
redisStandaloneConfiguration.setPassword(redisProperties.getPassword());
redisStandaloneConfiguration.setPort(redisProperties.getPort());
return new LettuceConnectionFactory(redisStandaloneConfiguration);
}
//集群版本
if(redisProperties.getCluster() != null) {
RedisClusterConfiguration redisClusterConfiguration = new RedisClusterConfiguration(redisProperties.getCluster().getNodes());
redisClusterConfiguration.setMaxRedirects(maxRedirects);
//支持自适应集群拓扑刷新和静态刷新源
ClusterTopologyRefreshOptions clusterTopologyRefreshOptions = ClusterTopologyRefreshOptions.builder()
.enablePeriodicRefresh()
.enableAllAdaptiveRefreshTriggers()
.refreshPeriod(Duration.ofSeconds(refreshTime))
.build();
ClusterClientOptions clusterClientOptions = ClusterClientOptions.builder()
.topologyRefreshOptions(clusterTopologyRefreshOptions).build();
//从优先，读写分离，读从可能存在不一致，最终一致性CP
LettuceClientConfiguration lettuceClientConfiguration = LettuceClientConfiguration.builder()
.readFrom(ReadFrom.SLAVE_PREFERRED)
.clientOptions(clusterClientOptions).build();
return new LettuceConnectionFactory(redisClusterConfiguration, lettuceClientConfiguration);
}
throw new MyException(ResultEnums.UNKONW_REDIS_TYPE);
}
@Bean
public RedisTemplate<Object, Object> redisTemplate(LettuceConnectionFactory redisConnectionFactory) {
RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(redisConnectionFactory);
Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
ObjectMapper om = new ObjectMapper();
SimpleModule simpleModule = new SimpleModule();
simpleModule.addSerializer(DateTime.class,new JodaDateTimeJsonSerializer());
simpleModule.addDeserializer(DateTime.class,new JodaDateTimeJsonDeserializer());
om.registerModule(simpleModule);
om.setVisibility(PropertyAccessor.ALL,JsonAutoDetect.Visibility.ANY);
om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
jackson2JsonRedisSerializer.setObjectMapper(om);
redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
redisTemplate.setKeySerializer(new StringRedisSerializer());
redisTemplate.afterPropertiesSet();
return redisTemplate;
}
}
package com.manlitech.cloudboot.basebootconfig.redis;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import org.joda.time.DateTime;
import java.io.IOException;
public class JodaDateTimeJsonSerializer extends JsonSerializer<DateTime> {
@Override
public void serialize(DateTime dateTime, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
jsonGenerator.writeString(dateTime.toString("yyyy-MM-dd HH:mm:ss"));
}
}
package com.manlitech.cloudboot.basebootconfig.redis;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import org.joda.time.DateTime;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
import java.io.IOException;
public class JodaDateTimeJsonDeserializer extends JsonDeserializer<DateTime> {
@Override
public DateTime deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
String dateString =jsonParser.readValueAs(String.class);
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss");
return DateTime.parse(dateString,formatter);
}
}