Specification

CaffeineSpec spec = CaffeineSpec.parse(
    "maximumWeight=1000, expireAfterWrite=10m, recordStats");
LoadingCache<Key, Graph> graphs = Caffeine.from(spec)
    .weigher((Key key, Graph graph) -> graph.vertices().size())
    .build(key -> createExpensiveGraph(key));

CaffeineSpec supports parsing a simple configuration format into a Caffeine builder. The string syntax is a series of comma-separated keys or key-value pairs, each corresponding to a builder method. This format does not support configuring builder methods with non-value parameters, such as removalListener, which must be configured in code.

The format supports the following builder methods. It is illegal to combine maximumSize with maximumWeight or weakValues with softValues.

• initialCapacity=[integer]: sets Caffeine.initialCapacity
• maximumSize=[long]: sets Caffeine.maximumSize
• maximumWeight=[long]: sets Caffeine.maximumWeight
• expireAfterAccess=[duration]: sets Caffeine.expireAfterAccess
• expireAfterWrite=[duration]: sets Caffeine.expireAfterWrite
• refreshAfterWrite=[duration]: sets Caffeine.refreshAfterWrite
• weakKeys: sets Caffeine.weakKeys
• weakValues: sets Caffeine.weakValues
• softValues: sets Caffeine.softValues
• recordStats: sets Caffeine.recordStats

A duration can be represented by an integer followed by one of "d", "h", "m", or "s", representing days, hours, minutes, or seconds respectively. Alternatively, as of v2.8.7, an ISO-8601 format string may be provided and is parsed by Duration.parse. For the purposes of a cache, all fractional values are rounded and negative durations throw an exception. Some examples of the two formats are below.

Short	ISO-8601	Description
50s	PT50S	50 seconds
11m	PT11M	11 minutes
6h	PT6H	6 hours
3d	P3D	3 days
	P3DT3H4M	3 days, 3 hours and 4 minutes