How do their APIs compare?

These two repositories are fundamentally different in purpose and structure, so "API comparison" means different things for each — let me break it down based on what's visible in the retrieved data.

jcsprout is not a library with a public API — it's a learning/reference repo. Its "verdict" per the RepoPilot analysis is WAIT — Stale, last commit 2y ago, which is an important signal on its own: this isn't an actively maintained artifact meant to be depended on. Structurally, it's a collection of standalone demo classes with main methods and inline Assert checks rather than a cohesive API surface. For example:

• [src/main/java/com/crossoverjie/actual/Search.java:L39-L118] defines a small in-memory word-search utility (addWord, search) backed by a ConcurrentHashMap, exercised directly from main with multiple threads and Assert calls — this is a self-contained algorithm demo, not something exposing a stable API for consumers.
• [src/main/java/com/crossoverjie/algorithm/BinaryNode.java:L12-L103] and [src/main/java/com/crossoverjie/algorithm/BinaryNodeTravel.java:L12-L122] are teaching implementations of binary tree traversal (level-order traversal via a queue), each with getters/setters and a createNode() helper to build sample trees for illustration.
• [src/main/java/com/crossoverjie/actual/LRUAbstractMap.java:L1-L26] documents (in comments) an LRU map with eviction and timeout callback design, illustrating a concept rather than shipping a reusable public interface.

So there's no consistent "API" contract across jcsprout — each class is an isolated example, often with main()-driven demonstration and assertions baked in, intended to be read and studied rather than imported as a dependency.

joda-time is a proper library with a well-defined, documented public API. It exposes stable interfaces and classes meant for external consumption:

• ReadableInstant [src/main/java/org/joda/time/ReadableInstant.java:L1-L37] — the base read-only interface for any point in time, expressed as milliseconds since epoch, explicitly documented as the recommended parameter type for methods that only need to read an instant.
• ReadableDuration [src/main/java/org/joda/time/ReadableDuration.java:L1-L38] and ReadablePartial [src/main/java/org/joda/time/ReadablePartial.java:L1-L37] extend this pattern of read-only interfaces representing durations and partial (local) times respectively, each documenting Comparable semantics and thread-safety/immutability guarantees.
• DateTimeComparator [src/main/java/org/joda/time/DateTimeComparator.java:L1-L47, L248-L285] is a public utility with equals/hashCode/toString implemented for correct use in collections, and documented as thread-safe and immutable — a hallmark of deliberate API design.
• Interval [src/main/java/org/joda/time/Interval.java:L1-L51] is another concrete public API type, documented with precise inclusive/exclusive semantics.
• DateTimeZone exposes pluggable extension points via Provider and NameProvider factories, configurable through system properties or setNameProvider/getDefaultProvider, guarded by SecurityManager permission checks [src/main/java/org/joda/time/DateTimeZone.java:L515-L634]. This shows a mature API designed for customization by consumers, with explicit security considerations.

Summary of the comparison:

• jcsprout has no real "API" in the library sense — it's example code with main-driven demos, and the RepoPilot verdict flags it as stale, meaning you shouldn't treat any of its classes as a stable interface to build against.
• joda-time has a deliberate, documented, versioned public API (Readable* interfaces, comparator/interval types, pluggable zone providers) with thread-safety and immutability contracts spelled out in Javadoc, and extension points guarded by security checks — this is what a production library API looks like.

If you want, I can dig further into either side — e.g., how jcsprout's demo classes are organized per topic, or how joda-time's Chronology/field system underpins its public API.

FOLLOW_UPS:

• What does joda-time's Chronology system provide?
• Why is jcsprout considered stale by RepoPilot?
• How does