core/pkgs/build-support/fetchmavenartifact/default.nix

# Adaptation of the MIT-licensed work on `sbt2nix` done by Charles O'Farrell

{ lib, fetchurl, stdenv }:
let
  defaultRepos = [
    "https://repo1.maven.org/maven2"
    "https://oss.sonatype.org/content/repositories/releases"
    "https://oss.sonatype.org/content/repositories/public"
    "https://repo.typesafe.com/typesafe/releases"
  ];

in args@{ # Example: "org.apache.httpcomponents"
groupId, # Example: "httpclient"
artifactId, # Example: "4.3.6"
version, # Example: "jdk11"
classifier ? null
, # List of maven repositories from where to fetch the artifact.
# Example: [ http://oss.sonatype.org/content/repositories/public ].
repos ? defaultRepos
  # The `url` and `urls` parameters, if specified should point to the JAR
  # file and will take precedence over the `repos` parameter. Only one of `url`
  # and `urls` can be specified, not both.
, url ? "", urls ? [ ]
, # The rest of the arguments are just forwarded to `fetchurl`.
... }:

# only one of url and urls can be specified at a time.
assert (url == "") || (urls == [ ]);
# if repos is empty, then url or urls must be specified.
assert (repos != [ ]) || (url != "") || (urls != [ ]);

let
  pname = (lib.replaceStrings [ "." ] [ "_" ] groupId) + "_"
    + (lib.replaceStrings [ "." ] [ "_" ] artifactId);
  suffix = lib.optionalString (classifier != null) "-${classifier}";
  filename = "${artifactId}-${version}${suffix}.jar";
  mkJarUrl = repoUrl:
    lib.concatStringsSep "/" [
      (lib.removeSuffix "/" repoUrl)
      (lib.replaceStrings [ "." ] [ "/" ] groupId)
      artifactId
      version
      filename
    ];
  urls_ = if url != "" then
    [ url ]
  else if urls != [ ] then
    urls
  else
    map mkJarUrl repos;
  jar = fetchurl (builtins.removeAttrs args [
    "groupId"
    "artifactId"
    "version"
    "classifier"
    "repos"
    "url"
  ] // {
    urls = urls_;
    name = "${pname}-${version}.jar";
  });
in stdenv.mkDerivation {
  inherit pname version;
  dontUnpack = true;
  # By moving the jar to $out/share/java we make it discoverable by java
  # packages packages that mention this derivation in their buildInputs.
  installPhase = ''
    mkdir -p $out/share/java
    ln -s ${jar} $out/share/java/${filename}
  '';
  # We also add a `jar` attribute that can be used to easily obtain the path
  # to the downloaded jar file.
  passthru.jar = jar;
}