How to Cache Null Values in Caffeine Cache
I'm Using Caffeine Cache to Store Data Received from an External System. Loadingcache clientCache = Caffeine. newBuilder(). expireAfterWrite(1, Timeunit...
I'm using Caffeine cache to store data received from an external system.
LoadingCache<String, String> clientCache = Caffeine.newBuilder().expireAfterWrite(1, TimeUnit.MINUTES).build(id -> {
System.out.println("Generating new value for " + id);
if (id.equalsIgnoreCase("1")) {
return null;
}
return new Date().toString();
});
System.out.println(clientCache.get("1"));
System.out.println(clientCache.get("1"));
System.out.println(clientCache.get("2"));
System.out.println(clientCache.get("3"));
This resulted,
Generating new value for 1
null
Generating new value for 1
null
Generating new value for 2
Wed May 20 17:11:01 IST 2020
Generating new value for 3
Wed May 20 17:11:01 IST 2020
Wed May 20 17:11:01 IST 2020
Caffeine is not saving null values in cache. How to store nulls in Caffeine?
1 Answer
From this issue report:
The cache does not allow storing null values. If you perform a computation and return null then this indicates the data doesn't exist and the caller receives null.
In addition, it advises:
Optionalis a good technique for negative caching.
Robert Thorne covers electric vehicle innovations, autonomous driving systems, global mobility trends, and automotive engineering developments.
