Result from Dicom4che call does not show umlaut characters

Question

I am using dcm4che to perform a query to the PACS, to search for patients. German patients are found by the search criteria (That has umlaut characters) but returning names have <?> characters instead of umlaut. How can I fix this?

private void setCharacterSet(Attributes attributes) {
        int tag = Tag.SpecificCharacterSet;
        VR vr = ElementDictionary.vrOf(tag, attributes.getPrivateCreator(tag));
        attributes.setString(tag, vr, "ISO_IR 110");
    }

I did add this character set but I don't think it's correct