How to specify files encoding?

I have troubles with deployment of my videogame for Windows 64 platform. After the export with embedded Java I can not read Cyrillic text from external files. This means - I can read normally Cyrrilc text from an external files when I launch the code from an IDE (Processing IDE or Intellij IDEa - both work perfect). But after export I receive only hieroglyphs. Hardcodded strings are shown normally. I tried three tools to create an executable release version of my videogame. They work perfect with LibGDX, but with Processing I receive this encoding error. I think I should force set the external files encoding when I read external files. Or there are another ways to set the encoding on UTF-8? How can I solve this problem?