HTTP cache

This page focuses on the HTTP cache. If you want to deduplicate the storage of your objects and/or notify your UI when your data changes, take a look at the normalized cache instead.

note
The HTTP cache is only available on Android and the JVM.

Setup

To enable HTTP cache support, add the dependency to your project's build.gradle file:

Kotlin
build.gradle[.kts]
1dependencies { 2 implementation("com.apollographql.apollo:apollo-http-cache:4.3.3") 3}

If you're targeting Android API level < 26, you'll need to enable core library desugaring to support the java.time API:

Kotlin
1android { 2 compileOptions { 3 // Flag to enable support for the new language APIs 4 coreLibraryDesugaringEnabled = true 5 } 6}

Then configure your HTTP cache:

Kotlin
1apolloClient = ApolloClient.Builder() 2 .httpCache( 3 // Use a dedicated directory for the cache 4 directory = File(pathToCacheDirectory), 5 // Configure a max size of 100MB 6 maxSize = 100 * 1024 * 1024 7 ) 8 .build()

Usage

The HTTP cache is a Least Recently Used (LRU) cache with a configurable max size.

Once your cache setup is complete, the cache will be used by default by all your queries. By default, queries will try to find a result in the cache first and go the network if it's not there. This is the HttpFetchPolicy.CacheFirst policy. You can customize that behaviour with httpFetchPolicy(HttpFetchPolicy):

Kotlin
1val response = apolloClient.query(query) 2 // Try the cache first - if it's a miss, try the network  3 .httpFetchPolicy(HttpFetchPolicy.CacheFirst) 4 5 // Only use the cache 6 .httpFetchPolicy(HttpFetchPolicy.CacheOnly) 7 8 // Try the network first - if there's an error, try the cache  9 .httpFetchPolicy(HttpFetchPolicy.NetworkFirst) 10 11 // Don't use the cache 12 .httpFetchPolicy(HttpFetchPolicy.NetworkOnly) 13  14 // Finally, execute your query 15 .execute()

Note: mutations and subscriptions don't go through the cache.

If the query is present in cache, it will be used to return response.data. If not, a HttpCacheMissException will be thrown.

You can also set an expiration time either globally or for specific queries. The entries will automatically be removed from the cache after the expiration time:

Kotlin
1// Globally 2apolloClient = ApolloClient.Builder() 3 .httpCache(/*...*/) 4 // Expire after 1 hour 5 .httpExpireTimeout(60 * 60 * 1000) 6 .build() 7 8// On a specific query 9val response = apolloClient.query(query) 10 // Expire after 1 hour 11 .httpExpireTimeout(60 * 60 * 1000) 12 .execute()

If a specific query must not be cached, you can use httpDoNotStore():

Kotlin
1val response = apolloClient.query(query) 2 // Don't cache this query 3 .httpDoNotStore(httpDoNotStore = true) 4 .execute()

Clearing the cache

Call apolloClient.httpCache.clearAll() to clear the cache of all entries.