List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); List<Integer> squares = Lists.newArrayList(numbers) .stream() .filter(n -> n % 2 == 0) .map(n -> n * n) .collect(Collectors.toList()); Function<Integer, String> toStringFunction = i -> String.valueOf(i); Map<Integer, String> numberMap = Maps.transformValues(someMap, toStringFunction); Cache<String, ResultSet> cache = CacheBuilder.newBuilder() .expireAfterAccess(1, TimeUnit.HOURS) .maximumSize(100) .build(); ResultSet result = cache.get(key, () -> expensiveDatabaseOperation());