在PDFOne for Java版本5发布以后，新增了一个数字签名功能，开发人员可以轻松利用控件提供的API创建签名程序，控件提供的PdfDocument.AddSignature()方法可以用于直接创建签名，具体代码如下：

import java.io.IOException;
import java.util.List;

import com.Gnostice.pdfone.PDFOne;
import com.Gnostice.pdfone.PdfDocument;
import com.Gnostice.pdfone.PdfException;
import com.Gnostice.pdfone.PdfFormField;
import com.Gnostice.pdfone.PdfFormSignatureField;
import com.Gnostice.pdfone.PdfRect;
import com.Gnostice.pdfone.PdfSignature;

public class Add_Signature {

  public static void main(String[] args) throws IOException, PdfException {

    // Load an existing PDF document
    PdfDocument doc = new PdfDocument();
    doc.load("transfer_details.pdf");

    // Add signature to the  document
    doc.addSignature("testmenow@mailinator.com.pfx",  // pathname of PFX
            "TestCase",                               // password for PFX
            "This is 100% genuine.",                  // description
            "Bank of Money, Internet",                // reason
            "test@example.com",                       // contact info
            1,                                        // page number
            "fldsig",                                 // field name
            new PdfRect(400,10,250,70));              // location

    // Save the document to file
    doc.save("signed_doc.pdf");

    // Close IO resources
    doc.close();
  }
}