spring cache实现一二级缓存

spring cache 抽象了cache，具体的实现可以随意组合。由于ConcurrentMapCache没有失效时间,虽然他是JVM最近的缓存，但用不好会是jvm很耗内存。所以退而求其次使用了caffeine（咖啡因缓存）这样可以实现进程缓存（有牛人可以解释下，我不是很明白什么是进程内缓存）。线面是spring整合caffeine缓存实现一二级缓存。

• 自定义缓存实现

public class MapCaffeCache implements Cache {

//	private ConcurrentMapCache mapCache = new ConcurrentMapCache("mapCache");

	private com.github.benmanes.caffeine.cache.@NonNull Cache mapCache = Caffeine.newBuilder()
			.expireAfterWrite(5, TimeUnit.SECONDS).expireAfterAccess(5, TimeUnit.SECONDS).maximumSize(5).build();
	private com.github.benmanes.caffeine.cache.@NonNull Cache caffeCache = Caffeine.newBuilder()
			.expireAfterWrite(1, TimeUnit.MINUTES).expireAfterAccess(1, TimeUnit.MINUTES).maximumSize(100).build();

	private String name = "userCache";

	@Override
	public String getName() {
		return this.name;
	}

	@Override
	public Object getNativeCache() {
		return this;
	}

	@Override
	public ValueWrapper get(Object key) {

		@Nullable
		Object ob = mapCache.getIfPresent(key);
		// 如果一级缓存有数据 直接返回 不触发二级缓存
		if (ob != null) {
			System.out.println(String.format("Cache L1 (CaffeineCache) :: %s = %s", key, ob));
			SimpleValueWrapper valueWrapper = new SimpleValueWrapper(ob);
			return valueWrapper;
		}

		Object obj = caffeCache.getIfPresent(key);
		if (obj != null) {
			SimpleValueWrapper valueWrapper2 = new SimpleValueWrapper(obj);
			System.out.println(String.format("Cache L2 (CaffeineCache) :: %s = %s", key, obj));
			// 如果二级缓存有数据 则更新到一级缓存
			mapCache.put(key, obj);
			return valueWrapper2;
		}
		return null;
	}

	@Override
	public  T get(Object key, Class type) {
		return (T) get(key).get();
	}

	@Override
	public  T get(Object key, Callable valueLoader) {
		return (T) get(key).get();
	}

	@Override
	public void put(Object key, Object value) {
		mapCache.put(key, value);
		caffeCache.put(key, value);
	}

	@Override
	public void evict(Object key) {
		mapCache.asMap().remove(key);
		caffeCache.asMap().remove(key);
	}

	@Override
	public void clear() {
		mapCache.asMap().clear();
		caffeCache.asMap().clear();
	}

}

• spring配置文件配置

 

• service 使用

// condition表达式为true缓存 表达式不可以和null运算、 unless返回true不缓存 unless表达式可以和null运算
	// (key 也可以表示为：key = "p0" 0表示第index参数做为key)
	@Cacheable(cacheManager = "cacheManager", key = "#i", value = "userCache", condition = "#i>7", unless = "#i>8")
	public String getList(int i) {
		return "list server method :: "
				+ LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
	}

	@Cacheable(cacheManager = "cacheManager", key = "#i", value = "userCache")
	public String getUsers(int i) {
		return "list server method :: "
				+ LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
	}

	@CachePut(cacheManager = "cacheManager", cacheNames = { "userCache" }, key = "#id")
	public String userUpdate(int id) {
		return "userUpdate server method :: "
				+ LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
	}