Java Guava组合Multimap和Cache

问题描述

是否有可用的组合Guava的缓存和 Multimap 功能？基本上，我需要一个集合，其中条目在给定时间后过期，例如 Cache 中可用，但我有非唯一键，我需要条目独立到期。

Is there any such thing as a combination of Guava's Cache and Multimap functionality available? Essentially, I need a collection where entries expire after a given time such as available in Cache but I have non-unique keys and I need the entries to expire independently.

推荐答案

我认为Louis Wasserman在上面的一条评论中提供了答案，即没有现成的组合 Multimap 和缓存可用。我已用下面的伪代码中概述的解决方案解决了我的问题/要求：

I think that Louis Wasserman provided the answer in one of the comments above, i.e. that there is no off-the-shelf combo of Multimap and Cache available. I have solved my problem/requirements with the solution outlined in pseudo-code below:

private Cache<Integer,Object> cache = CacheBuilder.newBuilder().SomeConfig.build();
private Multimap<Integer,Object> multimap = HashMultimap<Integer, Object>.create();
private AtomicInteger atomicid = new AtomicInteger(0);

public void putInMultimap(int id, Object obj) {
   int mapid = atomicid.addAndGet(1);
   cache.put(mapid,obj);
   multimap.put(id,mapid);
}
public List<Object> getFromMultimap(int id) {
   Set<Integer> mapids = multimap.get(id);
   List<Object> list = new ArrayList<Object>();
   for (int i : mapids) {
      list.add(cache.getIfPresent(i));
   }
   return list;
}

这个简单的解决方案有一些限制，但它对我来说没问题。

This simple 'solution' has some limitations but it works OK for me.

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