ADDITIONAL SYSTEM INFORMATION :
$ java -version
java version "22.0.1" 2024-04-16
Java(TM) SE Runtime Environment (build 22.0.1+8-16)
Java HotSpot(TM) 64-Bit Server VM (build 22.0.1+8-16, mixed mode, sharing)

Windows 10, Windows 11

Also in Java 17 and probably in any other Java older than 22.0.1

A DESCRIPTION OF THE PROBLEM :
If you run Java in Git Bash (MINGW64 based environment) it uses a wrong Charset in the System.out.

Git is a de-facto standard now and when you install it on Windows it comes with a UNIX-like Git Bash environment, based on MINGW64. Many Java developers use this Git Bash environment to build their code by Maven and Gradle and for running other R&D related things, including Java based tools.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. USe the Jansi library
2. Run it in the CMD window by a command like java -jar jansi-2.4.1.jar
3. Run it again in the Git Bash (MINGW64) window by a command like java -jar jansi-2.4.1.jar


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Both step 2 and step 3 should print a nice pseudo-graphics logo of the JANSI library, at the end of the demonstation.
ACTUAL -
Step 2 works properly
Step 3 prints question marks only instead, because System.out uses a wrong cp1252 encoding instead of UTF-8 one.

How I know what encoding is right in MINGW64? From either the "locale" command output or from the LC_* environment variables:

$ locale
LANG=
LC_CTYPE="en_GB.UTF-8"
LC_NUMERIC="C.UTF-8"
LC_TIME="C.UTF-8"
LC_COLLATE="C.UTF-8"
LC_MONETARY="C.UTF-8"
LC_MESSAGES="C.UTF-8"
LC_ALL=

$ echo $LC_CTYPE
en_GB.UTF-8


---------- BEGIN SOURCE ----------
A similar code used by the jansi-2.4.1.jar when jansi-2.4.1.jar is in your classpath:

import org.fusesource.jansi.AnsiMain;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

public class TestClass {
    public static void main(String[] args) {
        try (BufferedReader in = new BufferedReader(new InputStreamReader(AnsiMain.class.getResourceAsStream("jansi.txt"), StandardCharsets.UTF_8))) {
            for (String line = in.readLine(); line != null; line = in.readLine()) {
                System.out.println(line);
            }
        } catch (IOException e) {
            // ignore
        }
    }
}

You may also extract the jansi.txt file from the jansi-2.4.1.jar and work with it directly without the jansi-2.4.1.jar library in the classpath anymore.
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
import org.fusesource.jansi.AnsiMain;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;

public class TestClass {
    public static void main(String[] args) {
        try (BufferedReader in = new BufferedReader(new InputStreamReader(AnsiMain.class.getResourceAsStream("jansi.txt"), StandardCharsets.UTF_8))) {
            if (System.getenv("MSYSTEM") != null && System.getenv("MSYSTEM").startsWith("MINGW")) {
                Charset charset = Charset.forName(System.getenv("LC_CTYPE").split("\\.")[1]);
                for (String line = in.readLine(); line != null; line = in.readLine()) {
                    System.out.write(line.getBytes(charset));
                    System.out.println();
                }
            } else {
                for (String line = in.readLine(); line != null; line = in.readLine()) {
                    System.out.println(line);
                }
            }
        } catch (IOException e) {
            // ignore
        }
    }
}

FREQUENCY : always