PDF Encoding

Hi,
I try to read a UTF-8 file with Khmer characters and try to out it as a PDF using Aspose PDF. However, the output PDF is blank. May I know is Aspose support Khmer character ? The following is my code:

import java.io.File;
import java.nio.charset.Charset;
import aspose.pdf.*;
import org.apache.commons.io.FileUtils;

public class AsposePdf {

    public static void main(String[] args) throws Exception {
        new AsposePdf().createPdf();
    }

    public void createPdf() throws Exception {
        // Instantiate Pdf object by calling its empty constructor
        Pdf pdf = new Pdf();

        // Create a new section in the Pdf object
        Section sec = pdf.getSections().add();

        final String hello = FileUtils.readFileToString(new File("hello.txt"), Charset.forName("UTF-8"));

        // Create a new text paragraph and pass the text to its constructor as argument
        Text text = new Text(sec, hello);

        text.getTextInfo().setFontName("Arial Unicode MS");

        sec.getParagraphs().add(text);

        pdf.setUnicode();
        pdf.save("hello.pdf");
    }
}

Regards,
Cheong