import java.io.*;
import java.nio.file.*;
import java.nio.charset.*;

class Test {
    public static void main(String... arg) throws IOException {
        Path p = Files.write(Files.createTempFile("charset", "test"), new byte[] { -50 });
        try(Closeable c = () -> Files.delete(p)) {
            String s = Files.readString(p, StandardCharsets.UTF_16);
        }
    }
}