Use TextRise of a chunk to create supscript and subscript : Chunk « PDF « Java Tutorial

1. Java Tutorial
2. PDF
3. Chunk

import java.awt.Color;
import java.io.FileOutputStream;

import com.lowagie.text.Chunk;
import com.lowagie.text.Document;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfWriter;

public class MainClass {

  public static void main(String[] args) throws Exception {
    Document document = new Document();
    PdfWriter.getInstance(document, new FileOutputStream("2.pdf"));
    document.open();
    float textrise = 6.0f;
    Chunk c;
    for (String s : "this is a test".split(" ")) {
      c = new Chunk(s);
      c.setTextRise(textrise);
      c.setUnderline(new Color(0xC0, 0xC0, 0xC0), 0.2f, 0.0f, 0.0f, 0.0f,
          PdfContentByte.LINE_CAP_BUTT);
      document.add(c);
      textrise -= 2.0f;
    }
    document.close();
  }
}