JetChache如何实现缓存、更新、删除操作

缓存工具的对比

工具名称	功能对比	备注
Spring Cache	Spring官方提供，使用简单，功能单一，不能使用缓存刷新、二级缓存	对需求不高者可以使用
JetCache	阿里出品，原生的支持TTL、两级缓存、分布式自动刷新，还提供了Cache接口用于手工缓存操作。	对缓存要求高的用户推荐使用

快速接入

1.加依赖

            <dependency>
                <groupId>com.alicp.jetcache</groupId>
                <artifactId>jetcache-starter-redis-lettuce</artifactId>
                <version>2.6.0</version>
            </dependency>

2.加配置

在bootstrap.yml里增加如下配置

jetcache:
  statIntervalMinutes: 15
  areaInCacheName: false
  local:
    default:
      type: linkedhashmap
      keyConvertor: fastjson
  remote:
    default:
      type: redis.lettuce
      keyConvertor: fastjson
      uri: redis://127.0.0.1:6379/
      #uri: redis-sentinel://127.0.0.1:26379,127.0.0.1:26380,127.0.0.1:26381/?sentinelMasterId=mymaster
      #readFrom: slavePreferred

3.增加config配置类JetCacheConfiguration

package vip.mate.core.jetcache.config;

import com.alicp.jetcache.anno.CacheConsts;
import com.alicp.jetcache.anno.config.EnableCreateCacheAnnotation;
import com.alicp.jetcache.anno.config.EnableMethodCache;
import com.alicp.jetcache.anno.support.GlobalCacheConfig;
import com.alicp.jetcache.anno.support.SpringConfigProvider;
import com.alicp.jetcache.embedded.EmbeddedCacheBuilder;
import com.alicp.jetcache.embedded.LinkedHashMapCacheBuilder;
import com.alicp.jetcache.redis.lettuce.RedisLettuceCacheBuilder;
import com.alicp.jetcache.support.FastjsonKeyConvertor;
import com.alicp.jetcache.support.JavaValueDecoder;
import com.alicp.jetcache.support.JavaValueEncoder;
import io.lettuce.core.ClientOptions;
import io.lettuce.core.RedisClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import vip.mate.core.common.factory.YamlPropertySourceFactory;

import java.util.HashMap;
import java.util.Map;

@Configuration
@EnableMethodCache(basePackages = "vip.mate.system")
@EnableCreateCacheAnnotation
@PropertySource(factory = YamlPropertySourceFactory.class, value = "classpath:mate-jetcache.yml")
public class JetCacheConfiguration {
    @Bean
    public RedisClient redisClient(){
        RedisClient client = RedisClient.create("redis://127.0.0.1");
        client.setOptions(ClientOptions.builder().
                disconnectedBehavior(ClientOptions.DisconnectedBehavior.REJECT_COMMANDS)
                .build());
        return client;
    }

    @Bean
    public SpringConfigProvider springConfigProvider() {
        return new SpringConfigProvider();
    }

    @Bean
    public GlobalCacheConfig config(SpringConfigProvider configProvider, RedisClient redisClient){
        Map localBuilders = new HashMap();
        EmbeddedCacheBuilder localBuilder = LinkedHashMapCacheBuilder
                .createLinkedHashMapCacheBuilder()
                .keyConvertor(FastjsonKeyConvertor.INSTANCE);
        localBuilders.put(CacheConsts.DEFAULT_AREA, localBuilder);

        Map remoteBuilders = new HashMap();
        RedisLettuceCacheBuilder remoteCacheBuilder = RedisLettuceCacheBuilder.createRedisLettuceCacheBuilder()
                .keyConvertor(FastjsonKeyConvertor.INSTANCE)
                .valueEncoder(JavaValueEncoder.INSTANCE)
                .valueDecoder(JavaValueDecoder.INSTANCE)
                .redisClient(redisClient);
        remoteBuilders.put(CacheConsts.DEFAULT_AREA, remoteCacheBuilder);

        GlobalCacheConfig globalCacheConfig = new GlobalCacheConfig();
        // globalCacheConfig.setConfigProvider(configProvider);//for jetcache <=2.5
        globalCacheConfig.setLocalCacheBuilders(localBuilders);
        globalCacheConfig.setRemoteCacheBuilders(remoteBuilders);
        globalCacheConfig.setStatIntervalMinutes(15);
        globalCacheConfig.setAreaInCacheName(false);

        return globalCacheConfig;
    }

}

4.加注解

以下需要Spring或者SpringBoot环境

public interface UserService {
    @Cached(name="userCache.", key="#userId", expire = 3600)
    User getUserById(long userId);

    @CacheUpdate(name="userCache.", key="#user.userId", value="#user")
    void updateUser(User user);

    @CacheInvalidate(name="userCache.", key="#userId")
    void deleteUser(long userId);
}

使用@Cached注解可以为一个方法添加缓存，@CacheUpdate用于更新缓存，@CacheInvalidate用于移除缓存元素。

入坑提示

采用最新的2.6.0版本，有一个问题，就是采用jedis的方式的时候，提示一些报错信息，暂时调整为lettuce

代码参考

微服务源码，集成了JetCache
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