Guava Load Multiple Keys and Get multiple items

Question

I would like to use Guava as cache but I can't seem to find Guava has the capability of allowing me to load multiple items and get multiple items.

I see CacheLoader has the following:

    @Override
    public Value load(String key) {
        return getKey();
    }

And what I need to load is:

    @Override
    public List<Value> load(List<String> keys) {
        return getKeys();
    }

I would also expect to get one or a list of items from the cache, but I am happy even if I had to wrap that one item into a list just to get it.

I'm new to Guava and I'm not sure if Guava has such functionality?

Answer 1

You can use CacheLoader.loadAll() to load multiple items, and LoadingCache.getAll() to get them.

For example:

new CacheLoader<String, Value>() {
    @Override
    public Value load(String key) {
        return getKey();
    }

    @Override
    public Map<String, Value> load(Iterable<? extends String> keys) {
        return getKeys();
    }
}
//...
List<String> keys = Arrays.asList("key1", "key2", "key3");
ImmutableMap<String, Value> values = cache.getAll(keys);