I put 250_000 records to mongodb with java driving force, however forgot to set encoding explicitly, so after linux on my windows gadget system encoding modified to cp1251 and i've many records with values like Внедорожник 5 дв

i've a solution - just to go throw all gadgets, find and modify all string fields:

...
mc2.findOneAndUpdate(
new Document("canonical", canonical),
new Document("$set",
new Document("regionName",
new String(doc.getString("regionName").getBytes("cp1251"), "UTF-8"))));
...
Is there a way to do that without external program? (with some mongo js functions, utilities etc.)