<dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>30.1-jre</version> </dependency> ConcurrentMap<Key, Value> cache = new ConcurrentLinkedHashMap.Builder<Key, Value>() .build(); Value value = cache.get(key); if (value == null) { value = computeValue(key); cache.put(key, value); }