Is it proper use of CacheLoader?

I would like to ask what should I do on load method when cache does not contain the key. I add manually elements to the cache by put method:

@Override public void addResources(....) { SomeId someId = SomeId.builder() .... .build(); cache.put(someId, r.getResource()); } 

After that I'm looking for that key in LoadingCache. If it contains the key I get it by get method.

@Override

 public InputStream someMethod(String uri) throws ExecutionException { SomeId someId = SomeId.builder() ... .build(); if ( cache.asMap() .containsKey(someId) ) { return new ByteArrayInputStream(cache.get(someId)); } else { .... } return is; } } 

I initialize this cache that way:

 private static LoadingCache<SomeId, byte[]> cache; @PostConstruct public void init() { cache = CacheBuilder.newBuilder() .maximumSize(1000) .expireAfterWrite(24, TimeUnit.HOURS) .build(new CacheLoader<SomeId, byte[]>() { @Override public byte[] load(SomeId someId) { throw new IllegalStateException(""); } }); } 

I do now know what should I do inside it:

@Override public byte[] load(SomeId someId) { throw new IllegalStateException(""); } 

as I'm not loading elements from any db just from this cache. If elements is not inside cache than I should do nothing. It is worth to notice that I'm checking in method if key is present in cache

 if ( cache.asMap() .containsKey(someId) ) { return new ByteArrayInputStream(cache.get(someId));