Collections¶

Overview¶

Common collections utilities for map/list construction, map operations, reconciliation, and caching.

Architecture¶

Builders: MapBuilder and ListBuilder for fluent construction.
Utilities: MapUtils for merge/replace/copy and path creation.
Reconciliation: CollectionReconciler for current vs desired collections.
Caching: ConcurrentCache with TTL and eviction support.

Quick start¶

Gradle¶

1	`implementation("ie.bitstep.mango:mango4j-collections:1.0.0")`

Maven¶

<dependency>
    <groupId>ie.bitstep.mango</groupId>
    <artifactId>mango4j-collections</artifactId>
    <version>1.0.0</version>
</dependency>

Examples¶

All examples use classes from ie.bitstep.mango.collections.

MapBuilder¶

Fluent builder for nested maps.

Build a map¶

Map<String, String> map = MapBuilder.<String, String>map().build();

Build a map with specific implementation¶

Map<String, String> map = MapBuilder.<String, String>map(new TreeMap<>()).build();

Build a map and add items (nested)¶

Map<String, Object> map = MapBuilder.<String, Object>map()
    .with("first", "Tom")
    .with("last", "Cruise")
    .with("address",
        MapBuilder.<String, String>map()
            .with("line1", "One South County")
            .with("line2", "Leopardstown")
            .build()
    )
    .build();

ListBuilder¶

Fluent builder for lists, with optional concrete list implementations.

Build a list¶

List<String> list = ListBuilder.<String>list().build();

Build a list with specific implementation¶

List<String> list = ListBuilder.<String>list(new LinkedList<>()).build();

Build a list and add items¶

List<String> list = ListBuilder.<String>list()
    .add("Tom")
    .add("Cruise")
    .build();

Build a list from an existing collection¶

List<String> words = Arrays.asList("The", "cow", "jumped", "over", "the", "moon");
List<String> list = ListBuilder.<String>list().add(words).build();

MapUtils¶

Utilities for merging, replacing, copying, and list-wrapping map values.

Wrap values in lists¶

Map<String, String> input = MapBuilder.<String, String>map()
    .with("name", "java")
    .build();

Map<String, List<String>> output = MapUtils.entriesToList(input);

CollectionReconciler¶

Reconciles a current collection against a desired collection using a key extractor.

List<User> current = new ArrayList<>(List.of(new User("u1"), new User("u2")));
List<User> desired = List.of(new User("u2"), new User("u3"));

CollectionReconciler.reconcile(current, desired, User::id);

ConcurrentCache¶

TTL-based cache with eviction and optional AutoCloseable cleanup.

ScheduledExecutorService cleaner = Executors.newSingleThreadScheduledExecutor();
ConcurrentCache<String, String> cache = new ConcurrentCache<>(
    Duration.ofMinutes(10),
    Duration.ofMinutes(10),
    Duration.ofSeconds(5),
    Duration.ofMinutes(1),
    cleaner,
    Clock.systemUTC()
);

cache.put("token", "abc123");
String value = cache.get("token");