cache2k is an in-memory high performance Java Caching library.

  Cache<String,String> cache = new Cache2kBuilder<String, String>() {}
    .expireAfterWrite(5, TimeUnit.MINUTES)    // expire/refresh after 5 minutes
    .setupWith(UniversalResiliencePolicy::enable, b -> b // enable resilience policy
      .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.

• Small jar file (less than 400k) with no external dependencies
• Fastest access times, due to non blocking and wait free access of cached values, Blog article
• 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 API with stable and concise interface
• complete JCache / JSR107 support
• XML based configuration, to separate cache tuning from logic

• Spring Framework
• Scala Cache
• Datanucleus (via JCache)
• Hibernate (via JCache)

For more documentation and latest news, see the cache2k homepage.

See the Contributor Guide.