cache2k – High Performance Java Caching

cache2k focuses on providing a well engineered in-memory object cache implementation for Java applications.

Maven Central

  Cache<String,String> cache = new Cache2kBuilder<String, String>() {}
    .expireAfterWrite(5, TimeUnit.MINUTES)    // expire/refresh after 5 minutes
    .resilienceDuration(30, TimeUnit.SECONDS) // cope with at most 30 seconds
                                              // outage before propagating 
                                              // exceptions
    .refreshAhead(true)                       // keep fresh when expiring
    .loader(this::expensiveOperation)         // auto populating function
    .build();

For a detailed introduction continue with Getting Started.

Features at a glance

Single small jar file (less than 400k) with no external dependencies
Even smaller, for use with Android
One of the fastest cache for JVM local caching, see the benchmarks page
Java 6 and Android compatible
Leverages Java 8 to increase performance (if possible)
Pure Java code, no use of sun.misc.Unsafe
Thread safe, with a complete set of atomic operations
Resilience and smart exception handling
Null value support, see User Guide - Null Values
Automatic Expiry and Refresh: duration or point in time, variable expiry per entry, delta calculations
CacheLoader with blocking read through, see User Guide - Loading and Read Through
CacheWriter
Event listeners
Refresh ahead reduces latency
Low Overhead Statistics and JMX support
Separate and defined API with stable and concise interface
complete JCache / JSR107 support
XML based configuration, to separate cache tuning from logic

News

Version 1.0.0.Final, 2017-07-11: Minor documentation tweaks, allow more chars in a cache name, See Version 1.0.0.Final release notes
Version 1.0.0.CR4, 2017-03-21: Final cleanups and and API tweaks, Cache.computeIfAbsent(), See Version 1.0.0.CR4 release notes
Version 1.0.0.CR3, 2017-01-17: Cleanups&Documentation, improvements for Java 8, See Version 1.0.0.CR3 release notes
Version 1.0.0.CR2, 2016-12-22: Remove deprecated methods. Cleanups. Documentation. See Version 1.0.0.CR2 release notes
Version 1.0.0.CR1, 2016-12-05: More cleanups, XML configuration has arrived. See Version 1.0.0.CR1 release notes
Version 0.28-BETA, 2016-09-02: Minor bug fixes, SLF4J Support, statistics cleanup. See Version 0.28 release notes
Version 0.27-BETA, 2016-07-26: Performance improvements, leveraging Java 8, more API restructuring, cleanup and minor bug fixes. See Version 0.27 release notes
Version 0.26-BETA, 2016-05-06: Resilience policy, more API restructuring, cleanup and minor bug fixes. See Version 0.26 release notes

Integrating cache2k in your project

chacke2k is on maven central. Maven users add the following dependencies:

  <dependency>
    <groupId>org.cache2k</groupId>
    <artifactId>cache2k-api</artifactId>
    <version>${cache2k-version}</version>
    <scope>provided</scope>
  </dependency>
  <dependency>
    <groupId>org.cache2k</groupId>
    <artifactId>cache2k-all</artifactId>
    <version>${cache2k-version}</version>
    <scope>runtime</scope>
  </dependency>

Please replace ${cache2k-version} with the latest version.

Feedback

Please use the GitHub issue tracker for bugs and wishes you step upon. We also monitor the stackoverflow.com tag cache2k for general usage questions.

License

The code is released under Apache license.

Alternatives

cache2k does not try to be a full blown distributed enterprise caching solution. Some alternatives which you should take a look on:

Google Guava Cache
EHCache
JCS
Caffeine

Distributed caches:

Infinispan
hazelcast
redsisson
Apache ignite

Credits

Andrius Velykis for his maven reflow theme
Maximilian Richt for customizing the reflow theme and polishing the cache2k.org site design
Dr. Song Jiang for support, Hompage of Dr. Song Jiang