“UTF-8” encoding is not working in java build [closed]

You could use the Console class for that.The following code could give you some inspiration:

public class Foo {

    public static void main(String[] args) throws IOException {
        String s = "öäü";
        write(s);
    }

    private static void write(String s) throws IOException {
        String encoding = new OutputStreamWriter(System.out).getEncoding();
        Console console = System.console();
        if (console != null) {
            // if there is a console attached to the jvm, use it.
            System.out.println("Using encoding " + encoding + " (Console)");
            try (PrintWriter writer = console.writer()) {
                writer.write(s);
                writer.flush();
            }
        } else {
            // fall back to "normal" system out
            System.out.println("Using encoding " + encoding + " (System out)");
            System.out.print(s);
        }
    }
}

Tested on Windows 10(poowershell), Ubuntu 16.04(bash) with default settings. Also works from within IntelliJ (Windows and Linux).

From what I can tell, you either have the wrong character, which I don't think is the case, or you are trying to display it on a terminal that doesn't handle the character. I have written a short test to separate the issues.

public static void main(String[] args){
    String testA = "ֆޘᜅᾮ";
    String testB = "\u0586\u0798\u1705\u1FAE";

    System.out.println(testA.equals(testB));
    System.out.println(testA);
    System.out.println(testB);

    try(BufferedWriter check = Files.newBufferedWriter(
            Paths.get("uni-test.txt"),
            StandardCharsets.UTF_8,
            StandardOpenOption.CREATE,
            StandardOpenOption.TRUNCATE_EXISTING) ){
        check.write(testA);
        check.write("\n");
        check.write(testB);
        check.close();
    } catch(IOException ioc){

    }

}

You could replace the values with the characters you want.

The first line should print out true if the string is the actual string you want. After that it is a matter of displaying the characters. For example if I open the text file with less then half of them are broken. If I open it with firefox, then I see all four characters, but some are wonky. You'll need a font that has characters for the corresponding unicode value.

One thing you can do is open the file in a word processor and select a font that displays the characters you want correctly.

As suggested by the OP, including the -Dfile.encoding=UTF8causes the characters to display correctly when using System.out.println. Similar to this question which changes the encoding of System.out.