Guava CacheLoader 具有多个键，每个键都有自己的 refreshAfterWrite

Question

I currently have a CacheLoader

public class TransactionsDetailsCache extends CacheLoader<String, Transactions> {

    private final Client client;

    private final ExecutorService executor = Executors.newFixedThreadPool(1);

    public TransactionsDetailsCache(Client client) {
        this.client = checkNotNull(client);
    }

    @Override
    public Transactions load(String s) {
        return getTransactionsDetails(client);
    }

    // refreshing here by calling load
    @Override
    public ListenableFuture<Transactions> reload(String key, Transactions oldValue) {
        ListenableFutureTask<Transactions> task = ListenableFutureTask.create(() -> load(key));
        executor.execute(task);
        return task;
    }

    @VisibleForTesting
    protected Transactions getTransactionsDetails(Client Client) {
        Response response = client.getTransactions();

        final Set<TransactionDetails> deniedTransactions = response.stream()
                .filter(transaction -> "denied".equalsIgnoreCase(transaction.getType()))
                .collect(Collectors.toSet());

        final Set<TransactionDetails> allowedTransactions = response.stream()
                .filter(transaction -> "allowed".equalsIgnoreCase(transaction.getType()))
                .collect(Collectors.toSet());

        return new Transactions(allowedTransactions, deniedTransactions);
    }
}

and injecting it using

@Provides
@Singleton
public LoadingCache<String, Transactions> provideTransactionsDetails(Client client) {
    return CacheBuilder.newBuilder()
            .refreshAfterWrite(Duration.ofMinutes(60))
            .build(new TransactionsDetailsCache(client);
}

and my Transactions looks like

@Data
public class Transactions {
    Set<TransactionDetails> allowedTransactions;
    Set<TransactionDetails> deniedTransactions;
}

I am currently using the following to get Transactions object.

transactions = cache.get("transactions");

I want to set different refreshAfterWrite times to allowedTransactions and deniedTransactions and get them using same cache. Is this possible using a single CacheLoader? I see that a key can be passed to reload method but not sure how to use it and refreshAfterWrite different for each key.

allowedTransactions = cache.get("allowedTransactions");
deniedTransactions = cache.get("deniedTransactions");

I want cache with key allowedTransactions to reload after 1 hour, and with key deniedTransactions to reload after 5 minutes.

I do not want to have different caches because both allowedTransactions and deniedTransactions are received from single API call and want them to be in single cache. I feel like this can be achieved with using different key , but not sure how to get expiry for each key, time of last refresh is not stored anywhere.

Answer 1

This feature is not supported by Guava. (I don't believe it's even supported by Caffeine, which is a more advanced replacement for Guava's cache.)