A early stage cache library for Java 8 applications, created to deliver a delightful programming interface, performance, focusing in bulk operations to maximize throughput and without any pretensions to implement JSR107.

Currently we have just the Redis as cache storage backend, but another one can be added by implementing a small set of basic operations.

Since 2015.

Initialize it:

CacheFuns<String, String> cache = new CacheFuns<String, String>(
        new RedisCacheOperations(new JedisPool("localhost")),
                /* KeyMapper */,
                /* ValueMapper */);

Where CacheFuns is defined as this: CacheFuns<K, T> where K is the type of the key, and T is the type of the stored object.

So, with the cache initialized, you can do a simple get:

Optional<String> value = cache.get("key1");

But you can also pass a Supplier<T> as parameters to supply the value when it is missing in the cache, and automatically the value loaded from our data source is stored, as this example demonstrates:

Optional<String> value = cache.get("key1", (id) -> Optional.of("Value1"))
value.get(); // returns Value1
cache.get("key1").isPresent(); // returns true.

Or you can get a stream of stored values using streamOf methods:

cache.streamOf(Arrays.asList("Key1", "Key2", "Key3"))
     .filter(...)
     .forEach(...)

Or even you can use the supplyStreamOf to get a Supplier of an Stream:

Supplier<Stream<Optional<T>>> supplierOfCustomers = cache.supplyStreamOf(Arrays.asList("Customer1", "Customer2")
...
supplierOfCustomers.get(); // Finally executes the operation.

It also has a streamOf method that accepts a function which you can provide the real values for missing keys:

Collection<String> customerIds = Arrays.asList("Customer1", "Customer2", "CustomerN")

Stream<Optional<String>> customersStream = cache.streamOf(ids, (id) -> {
  /* 
  Loads the customer from database based on given 'id'
  */
})

Using Redis as backend, all batch operations (such as getAll, streamOf and supplyStreamOf) are done pipelined to maximize performance.

Being 'functional' give us more power to compose operations, as an example, you can create L1 L2 cache operations easily just by composing these functions. Let's take a look at these examples, given two caches, one of them l1 is a fast in-memory cache, and a l2, a Redis acting as cache, slower than L1 of course.

And the get is defined as this: Supplier<Optional<T>> get(final K id, final Supplier<Optional<T>> supplier), you can do a L1 L2 get:

Optional<String> value = //
        l1.get(key, //
        l2.get(key, () -> Optional.of(/* something loading from database by example */))).get();

It tries to load from l1, after l2 and finally hits the database if the caches didn't found the stored value represented by its key. You can compose N caches, but we don't know why you need this, but who knows.

For further details and examples, take a look at the unit tests. We are working hard on this library, and very soon you gonna see some new features and support to another backends.

The MIT License (MIT)

Copyright (c) 2015 cachefun

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.