add nix package for wrapped jdtls

nix/cgnix/nvim-tools/default.nix

@@ -23,7 +23,7 @@ let
       nativeBuildInputs = with pkgs; [ zig_0_12.hook git ];
     })
     (pkgs.callPackage ./haxe-language-server.nix { })
-    jdt-language-server
+    config.output.packages.jdtls-wrapped
     lua-language-server
     (flakePkg "github:oxalica/nil")
     ocamlPackages.ocaml-lsp

nix/pkgs/default.nix

@@ -1,6 +1,7 @@
 { ... }:
 {
   imports = [
+    ./jdtls-wrapped.nix
     ./thumbnailers.nix
   ];
 }

nix/pkgs/jdtls-wrapped.nix

@@ -0,0 +1,11 @@
+# A wrapper around jdtls that provides the correct Java version
+
+{ pkgs, ... }:
+{
+  output.packages.jdtls-wrapped = pkgs.writeShellScriptBin "jdtls" ''
+    export PATH="$PATH:${pkgs.jre17_minimal}/bin"
+    export JAVA_HOME="${pkgs.jre17_minimal}"
+
+    exec "${pkgs.jdt-language-server}/bin/jdtls" "$@"
+  '';
+}