class SetField
{
    /**
     * This will set a single field in the document.
     *
     * @param pdfDocument The PDF to set the field in.
     * @param name The name of the field to set.
     * @param value The new value of the field.
     *
     * @throws IOException If there is an error setting the field.
     */
    public void setField(PDDocument pdfDocument, String name, String value) throws IOException
    {
        PDDocumentCatalog docCatalog = pdfDocument.getDocumentCatalog();
        PDAcroForm acroForm = docCatalog.getAcroForm();
        PDField field = acroForm.getField(name);
        if (field != null)
        {
            if (field instanceof PDCheckBox)
            {
                PDCheckBox checkbox = (PDCheckBox) field;
                if (value.isEmpty())
                {
                    checkbox.unCheck();
                }
                else
                {
                    checkbox.check();
                }
            }
            else if (field instanceof PDComboBox)
            {
                field.setValue(value);
            }
            else if (field instanceof PDListBox)
            {
                field.setValue(value);
            }
            else if (field instanceof PDRadioButton)
            {
                field.setValue(value);
            }
            else if (field instanceof PDTextField)
            {
                field.setValue(value);
            } 
        }
        else
        {
            System.err.println("No field found with name:" + name);
        }
    }

    /**
     * This will read a PDF file and set a field and then write it the pdf out
     * again. <br>
     * see usage() for commandline
     *
     * @param args command line arguments
     *
     * @throws IOException If there is an error importing the FDF document.
     */
    public static void main(String[] args) throws IOException
    {
        SetField setter = new SetField();
        setter.setField(args);
    }

    private void setField(String[] args) throws IOException
    {<FILL_FUNCTION_BODY>}

    private static String calculateOutputFilename(String filename)
    {
        String outputFilename;
        if (filename.toLowerCase().endsWith(".pdf"))
        {
            outputFilename = filename.substring(0, filename.length() - 4);
        }
        else
        {
            outputFilename = filename;
        }
        outputFilename += "_filled.pdf";
        return outputFilename;
    }

    /**
     * This will print out a message telling how to use this example.
     */
    private static void usage()
    {
        System.err.println("usage: org.apache.pdfbox.examples.interactive.form.SetField <pdf-file> <field-name> <field-value>");
    }
}

        PDDocument pdf = null;
        try
        {
            if (args.length != 3)
            {
                usage();
            }
            else
            {
                SetField example = new SetField();
                pdf = Loader.loadPDF(new File(args[0]));
                example.setField(pdf, args[1], args[2]);
                pdf.save(calculateOutputFilename(args[0]));
            }
        }
        finally
        {
            if (pdf != null)
            {
                pdf.close();
            }
        }
    
<no_super_class>