Add flake support

Author: Guilvareux

flake.lock

@@ -0,0 +1,61 @@
+{
+    description = "Make Groovy Language Server";
+
+    inputs = {
+        nixpkgs.url = "nixpkgs";
+        flake-utils.url = "github:numtide/flake-utils";
+    };
+
+    outputs = { nixpkgs, flake-utils, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+        lib = nixpkgs.lib;
+        pkgs = import nixpkgs {
+            inherit system;
+            config = {allowUnfree = true;};
+        };
+    in {
+        packages.default = pkgs.stdenvNoCC.mkDerivation rec {
+            pname = "groovy-language-server";
+            version = "0-unstable-2025-12-03";
+
+            src = pkgs.fetchFromGitHub {
+                name = "${pname}-${version}";
+                owner = "GroovyLanguageServer";
+                repo = "groovy-language-server";
+                rev = "0746b250604c0a75bf620f7257aed8df12d025c3";
+                sha256 = "sha256-rLi6xvGFVRvAVmP59Te1MxKA6HzQ+qPtEC5lMws5tFQ=";
+            };
+
+            buildInputs = with pkgs; [
+                jdk
+                gradle
+                makeWrapper
+            ];
+
+            buildPhase = ''
+                ./gradlew build
+            '';
+
+            installPhase = ''
+                mkdir -p $out/share/java
+                mkdir -p $out/bin
+
+                cp build/libs/${pname}-${version}-all.jar $out/share/java
+
+                makeWrapper "${pkgs.jdk}/bin/java" "$out/bin/${pname}" \
+                --add-flags "-jar $out/share/java/${pname}-${version}-all.jar" \
+                --set CLASSPATH "$out/share/java/${pname}-${version}-all.jar:\$CLASSPATH"
+            '';
+
+            meta = with lib; {
+                homepage = "https://github.com/GroovyLanguageServer/groovy-language-server";
+                description = "Groovy Language Server";
+                longDescription = "Groovy Language Server";
+                license = licenses.asl20;
+                platforms = platforms.all;
+                maintainers = [ ];
+            };
+        };
+    });
+}