How can I convert UTF-16 to UTF-32 in java?

I have looked for solutions, but there doesn't seem to be much on this topic. I have found solutions that suggest:

String unicodeString = new String("utf8 here");
byte[] bytes = String.getBytes("UTF8"); 
String converted = new String(bytes,"UTF16");

for converting to utf16 from utf8, however, java doesn't handle "UTF32", which makes this solution unviable. Does anyone know any other way on how to achieve this?

after searching I got this to work:

    public static String convert16to32(String toConvert){
        for (int i = 0; i < toConvert.length(); ) {
            int codePoint = Character.codePointAt(toConvert, i);
            i += Character.charCount(codePoint);
            //System.out.printf("%x%n", codePoint);
            String utf32 = String.format("0x%x%n", codePoint);
            return utf32;
        }
        return null;
    }