Question: What is the best distributed cache for Java?

Answer

When it comes to choosing a distributed caching solution for Java, there are several options and the best one for your use case will depend on your specific requirements. However, below are some popular solutions:

1. Ehcache

Ehcache is an open-source, standards-based cache that boosts performance, offloads your database, and simplifies scalability. It's robust, proven, and full-featured, which makes it an ideal choice.

Here is a simple example of how to use Ehcache:

CacheManager cacheManager = CacheManager.getInstance();
Cache cache = cacheManager.getCache("myCache");

Element element = new Element("key1", "value1");
cache.put(element);

Element value = cache.get("key1");

2. Hazelcast

Hazelcast is another popular option. Hazelcast IMDG (In-Memory Data Grid) is an open-source distributed in-memory object store supporting a wide variety of data structures.

Here is how you might use Hazelcast in a simple application:

HazelcastInstance hz = Hazelcast.newHazelcastInstance();
IMap<String, String> map = hz.getMap( "my-distributed-map" );
map.put( "key", "value" );

String currentValue = map.get( "key" );

3. Infinispan

Infinispan is an open-source data grid platform and highly scalable caching solution. It offers features like transactions, eviction, and querying which can be beneficial for certain use cases.

A basic usage example of Infinispan looks like this:

DefaultCacheManager manager = new DefaultCacheManager();
Cache<String, String> cache = manager.getCache();

cache.put("key", "value");
String value = cache.get("key");

Remember, each of these options has their own strengths and weaknesses, and might work better or worse depending on your particular needs. Always evaluate multiple options and choose the one that fits your project requirements best.