Caffeine is a high performance, near optimal caching library based on Java 8. For more details, see our user's guide and browse the API docs for the latest release.

Caffeine provides an in-memory cache using a Google Guava inspired API. The improvements draw on our experience designing Guava's cache and ConcurrentLinkedHashMap.

LoadingCache<Key, Graph> graphs = Caffeine.newBuilder()
    .maximumSize(10_000)
    .expireAfterAccess(5, TimeUnit.MINUTES)
    .refreshAfterWrite(1, TimeUnit.MINUTES)
    .build(key -> createExpensiveGraph(key));

Caffeine provides flexible construction to create a cache with a combination of the following features:

• automatic loading of entries into the cache, optionally asynchronously
• size-based eviction when a maximum is exceeded based on frequency and recency
• time-based expiration of entries, measured since last access or last write
• asynchronously refresh when the first stale request for an entry occurs
• keys automatically wrapped in weak references
• values automatically wrapped in weak or soft references
• notification of evicted (or otherwise removed) entries
• writes propagated to an external resource
• accumulation of cache access statistics

In addition, Caffeine offers the following extensions:

• JSR-107 JCache
• Guava adapters
• Simulation

Use Caffeine in a community provided integration:

• Spring Cache (upcoming Spring 4.3 & Boot 1.4 releases)
• ScalaCache: Simple caching in Scala
• Scaffeine: Scala wrapper for Caffeine
• Ratpack (upcoming 1.3 release)

• A short look at what Caffeine brings to your applications.
  • Add a Boost of Caffeine to Your Java at VOXXED
• A in-depth description of Caffeine's architecture.
  • Design of a Modern Cache at HighScalability
• Caffeine is presented as part of a research paper evaluating its novel eviction policy.
  • TinyLFU: A Highly Efficient Cache Admission Policy by Gil Einziger, Roy Friedman, Ben Manes

On the radar,

• Early discussions with HBase, Cassandra, Solr, and ElasticSearch
• Postgres is evaluating whether to port the cache
• Go implementation of the W-TinyLfu policy

Download from Maven Central or depend via Gradle:

compile 'com.github.ben-manes.caffeine:caffeine:2.3.0'

// Optional extensions
compile 'com.github.ben-manes.caffeine:guava:2.3.0'
compile 'com.github.ben-manes.caffeine:jcache:2.3.0'

See the release notes for details of the changes.

Snapshots of the development version are available in Sonatype's snapshots repository.