private static Map<Integer, XWPFRun> getPosToRuns(XWPFParagraph paragraph) {
    int pos = 0;
    Map<Integer, XWPFRun> map = new HashMap<>(10);
    for (XWPFRun run : paragraph.getRuns()) {
        String runText = run.getText(run.getTextPosition());
        for (int i = 0; i < runText.length(); i++) {
            map.put(pos + i, run);
        }
        pos += runText.length();
    }
    return (map);
}

public static <V> void replace(XWPFDocument document, Map<String, V> map) {
    List<XWPFParagraph> paragraphs = document.getParagraphs();
    for (XWPFParagraph xwpfParagraph : paragraphs) {
        replace(xwpfParagraph, map);
    }
}

private static <V> void replace(XWPFParagraph paragraph, Map<String, V> map) {
    for (Map.Entry<String, V> entry : map.entrySet()) {
        int pos = paragraph.getText().indexOf(entry.getKey());
        if (pos >= 0) {
            Map<Integer, XWPFRun> posToRuns = getPosToRuns(paragraph);
            XWPFRun run = posToRuns.get(pos);
            XWPFRun lastRun = posToRuns.get(pos + entry.getKey().length() - 1);
            int runNum = paragraph.getRuns().indexOf(run);
            int lastRunNum = paragraph.getRuns().indexOf(lastRun);
            String texts[] = entry.getValue().toString().split("n");
            run.setText(texts[0], 0);
            XWPFRun newRun = run;
            for (int i = 1; i < texts.length; i++) {
                newRun.addCarriageReturn();
                newRun = paragraph.insertNewRun(runNum + i);
                newRun.setText(texts[i]);
                newRun.setBold(run.isBold());
                newRun.setCapitalized(run.isCapitalized());
                // newRun.setCharacterSpacing(run.getCharacterSpacing());
                newRun.setColor(run.getColor());
                newRun.setDoubleStrikethrough(run.isDoubleStrikeThrough());
                newRun.setEmbossed(run.isEmbossed());
                newRun.setFontFamily(run.getFontFamily());
                newRun.setFontSize(run.getFontSize());
                newRun.setImprinted(run.isImprinted());
                newRun.setItalic(run.isItalic());
                newRun.setKerning(run.getKerning());
                newRun.setShadow(run.isShadowed());
                newRun.setSmallCaps(run.isSmallCaps());
                newRun.setStrikeThrough(run.isStrikeThrough());
                newRun.setSubscript(run.getSubscript());
                newRun.setUnderline(run.getUnderline());
            }
            for (int i = lastRunNum + texts.length - 1; i > runNum + texts.length - 1; i--) {
                paragraph.removeRun(i);
            }
        }
    }
}