如何使番石榴缓存值永久

Question

Is it possible, using Google Guava's Cache, to keep my cached value in the cache permanently?

Below is how I build my cache:

cache = CacheBuilder.newBuilder()               
                .expireAfterWrite(60, TimeUnit.MINUTES)
                .maximumSize(100)
                .build(....);

I want my cache to keep the value permanently (currently it's 60 minutes). Is there any method of doing so?

Answer 1

Just remove expireAfterWrite from builder (it's optional feature):

cache = CacheBuilder.newBuilder()
            .maximumSize(100)
            .build(....);

so that entries will be evicted only when maximumSize is reached.

Guava's Cache is well documented but you should probably read Wiki page too.

PS If by "permanent" you meant "will be there after restart", Guava Cache isn't for you since it's in-memory cache.

Answer 2

Simply change the value in builder:

cache = CacheBuilder.newBuilder()               
            .expireAfterWrite(Long.MAX_VALUE, TimeUnit.DAYS)
            .maximumSize(Long.MAX_VALUE)
            .build(....);