j2chache

1.什么是j2cache?

J2cache是OSChina开发的一款二级缓存框架,但它并没有重复造*而是将资源进行了一个整合，即将Ehcache、Caffeine、redis、Spring Cache等进行整合。

J2cache分为2层缓存结构 第一层为进程式缓存caffeine 第二层为集中式缓存 redis

j2cache从1.3.0版本开始支持JGroups和Redis Pub/Sub两种方式进行缓存事件的通知。

2. 快速入门j2cache

1.导入maven坐标

 <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>net.oschina.j2cache</groupId>
            <artifactId>j2cache-spring-boot2-starter</artifactId>
            <version>2.8.0-release</version>
        </dependency>

        <dependency>
            <groupId>net.oschina.j2cache</groupId>
            <artifactId>j2cache-core</artifactId>
            <version>2.8.0-release</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-simple</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

2.yml配置文件

server:
  port: 9000
pinda:
  redis:
    ip: 127.0.0.1
    port: 6379
    database: 0
spring:
  redis:
    host: ${pinda.redis.ip}
    port: ${pinda.redis.port}
    database: ${pinda.redis.database}
j2cache:
  cache-clean-mode: passive
  allow-null-values: true
  redis-client: lettuce #指定redis客户端使用lettuce，也可以使用Jedis
  l2-cache-open: true #开启二级缓存
  broadcast: net.oschina.j2cache.cache.support.redis.SpringRedisPubSubPolicy
  #  broadcast: jgroups
  L1: #指定一级缓存提供者为caffeine
    provider_class: caffeine
  L2: #指定二级缓存提供者为redis
    provider_class: net.oschina.j2cache.cache.support.redis.SpringRedisProvider
    config_section: lettuce
  sync_ttl_to_redis: true
  default_cache_null_object: false
  serialization: fst  #序列化方式：fst、kyro、Java
caffeine:
  properties: /caffeine.properties   # 这个配置文件需要放在项目中
lettuce:
  mode: single
  namespace:
  storage: generic
  channel: j2cache
  scheme: redis
  hosts: ${pinda.redis.ip}:${pinda.redis.port}
  password: ${pinda.redis.password}
  database: ${pinda.redis.database}
  sentinelMasterId:
  maxTotal: 100
  maxIdle: 10
  minIdle: 10
  timeout: 10000
      
      
-----------------------------------------------------------------L1一级缓存配置-----------------------------------------------------------------------------
# Caffeine configuration
# [name] = size, xxxx[s|m|h|d]
default=2000, 2h
rx=50, 2h

3.常用方法

  @Autowired
    private CacheChannel cacheChannel;

    private String region = "abc";
    private String key = "location";

    /**
     * 获取缓存
     *
     * @return
     */
    @GetMapping("/getCacheData")
    public List<String> getCacheData() {
        CacheObject cacheObject = cacheChannel.get(region, key);
        // 如果缓存中没有数据
        if (Objects.isNull(cacheObject.getValue())) {
            List<String> list = new ArrayList<>();
            list.add("TOP");
            list.add("JUG");
            list.add("MID");
            list.add("AD");
            list.add("SUP");
            // 设置缓存
            cacheChannel.set(region, key, list);
        }
        return (List<String>) cacheObject.getValue();
    }

    //清理指定缓存
    @GetMapping("/evict")
    public String evict() {
        cacheChannel.evict(region, key);
        return "evict";
    }

    //检测存在那级缓存
    @GetMapping("/check")
    public String check() {
        int check = cacheChannel.check(region, key);
        return "level:" + check;
    }


    //检测缓存数据是否存在
    @GetMapping("/exists")
    public String exists() {
        boolean exists = cacheChannel.exists(region, key);
        return "exists:" + exists;
    }


    //清理指定区域的缓存
    @GetMapping("/clear")
    public String clear() {
        cacheChannel.clear(region);
        return "clear";
    }