Maven Metadata Details and Gradle Lockfile Formats

First, as you can see above, while normal artifacts have the same `base-version` and `version`, for snapshots it usually (but not necessarily) differs. Second, for figuring out where to download the snapshot, Gradle consults `maven-metadata.xml`. With that in mind... ## Maven Metadata (Reference: [Maven Metadata](https://maven.apache.org/repositories/metadata.html), [Metadata](https://maven.apache.org/ref/3.9.8/maven-repository-metadata/repository-metadata.html) Maven metadata files are called `maven-metadata.xml`. There are three levels of metadata: "G level", "A level", "V level", representing group, artifact, or version metadata. G level metadata is currently unsupported. It's only used for Maven plugins, which Gradle presumably doesn't use. A level metadata is used for getting the version list for an artifact. It's an xml with the following items: - `<groupId>` - group ID - `<artifactId>` - artifact ID - `<versioning>` - `<latest>` - the very latest base version (e.g. `2.2.1-SNAPSHOT`) - `<release>` - the latest non-snapshot version - `<versions>` - the version list, each in a `<version>` tag - `<lastUpdated>` - the metadata update timestamp (UTC, `YYYYMMDDHHMMSS`) V level metadata is used for listing the snapshot versions. It has the following items: - `<groupId>` - group ID - `<artifactId>` - artifact ID - `<versioning>` - `<lastUpdated>` - the metadata update timestamp (UTC, `YYYYMMDDHHMMSS`) - `<snapshot>` - info about the latest snapshot version - `<timestamp>` - build timestamp (UTC, `YYYYMMDD.HHMMSS`) - `<buildNumber>` - build number - `<snapshotVersions>` - the list of all available snapshot file info, each info is enclosed in a `<snapshotVersion>` - `<classifier>` - classifier (optional) - `<extension>` - file extension - `<value>` - snapshot version (as opposed to base version) - `<updated>` - snapshot build timestamp (UTC, `YYYYMMDDHHMMSS`) ## Lockfile Format The mitm-cache lockfile format is described in the [mitm-cache README](https://github.com/chayleaf/mitm-cache#readme). The Nixpkgs Gradle lockfile format is more complicated: ```json { "!comment": "This is a Nixpkgs Gradle dependency lockfile. For more details, refer to the Gradle section in the Nixpkgs manual.", "!version": 1, "https://oss.sonatype.org/content/repositories/snapshots/com/badlogicgames/gdx-controllers": { "gdx-controllers#gdx-controllers-core/2.2.4-20231021.200112-6/SNAPSHOT": {

This chunk elaborates on Maven metadata, specifically detailing the structure and contents of A-level and V-level `maven-metadata.xml` files. A-level metadata provides artifact version lists, including `<latest>`, `<release>`, and `<lastUpdated>` timestamps, while V-level metadata focuses on snapshot versions, containing `<snapshot>` information (timestamp, build number) and a list of specific `<snapshotVersions>` with classifiers, extensions, values, and update times. Following this, the document introduces lockfile formats, referencing the `mitm-cache` lockfile and then presenting the more complex Nixpkgs Gradle lockfile format with a JSON example, highlighting its comment, version, and repository-specific artifact entry structure.