import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import com.lowagie.text.Document;
import com.lowagie.text.PageSize;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.AcroFields;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.GrayColor;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;
import com.lowagie.text.pdf.PdfWriter;
import com.lowagie.text.pdf.RandomAccessFileOrArray;
import com.lowagie.text.pdf.TextField;
public class MainClass {
public static void main(String[] args) throws Exception {
createPdf("HelloLetter.pdf", "field", "value");
RandomAccessFileOrArray letter = new RandomAccessFileOrArray("HelloLetter.pdf");
PdfReader reader = new PdfReader(letter, null);
ByteArrayOutputStream baos1 = new ByteArrayOutputStream();
PdfStamper stamper = new PdfStamper(reader, baos1);
AcroFields form = stamper.getAcroFields();
form.renameField("field", "field1");
stamper.close();
reader = new PdfReader(letter, null);
ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
stamper = new PdfStamper(reader, baos2);
form = stamper.getAcroFields();
form.renameField("field", "field2");
stamper.close();
}
private static void createPdf(String filename, String field, String value) throws Exception {
Document document = new Document(PageSize.A4);
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(filename));
document.open();
BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.WINANSI, BaseFont.NOT_EMBEDDED);
TextField tf = new TextField(writer, new Rectangle(64, 785, 340, 800), field);
tf.setFontSize(12);
tf.setFont(bf);
tf.setText(value);
tf.setTextColor(new GrayColor(0.5f));
writer.addAnnotation(tf.getTextField());
document.close();
}
}