{
  description = "Java dev environment";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";

  outputs = { self, nixpkgs }:
    let
      systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
      forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f {
        pkgs = import nixpkgs { inherit system; };
      });
    in
    {
      packages = forAllSystems ({ pkgs }: {
        default = pkgs.stdenv.mkDerivation {
          pname = "hello-java";
          version = "0.1.0";
          src = ./.;
          nativeBuildInputs = [ pkgs.jdk ];
          buildPhase = ''
            javac hello.java
          '';
          installPhase = ''
            mkdir -p $out/share/java $out/bin
            cp hello.class $out/share/java/
            cat > $out/bin/hello-java <<EOF
            #!${pkgs.bash}/bin/bash
            exec ${pkgs.jre}/bin/java -cp $out/share/java hello
            EOF
            chmod +x $out/bin/hello-java
          '';
        };
      });

      devShells = forAllSystems ({ pkgs }: {
        default = pkgs.mkShell {
          packages = with pkgs; [
            jdk
            gradle
            maven
          ];

          JAVA_HOME = "${pkgs.jdk}";
        };
      });

      apps = forAllSystems ({ pkgs }: {
        default = {
          type = "app";
          program = "${self.packages.${pkgs.system}.default}/bin/hello-java";
        };
      });
    };
}