Fill PDF Form Fields in Java

import com.spire.pdf.FileFormat;
import com.spire.pdf.PdfDocument;
import com.spire.pdf.fields.PdfField;
import com.spire.pdf.widget.*;


public class FillFormField{
    public static void main(String[] args){
    	
        //create a PdfDocument object
        PdfDocument doc = new PdfDocument();
        
        //load a sample PDF containing forms
        doc.loadFromFile("G:\\java-workspace\\Spire.Pdf\\Forms.pdf");

        //get the form fields from the document
        PdfFormWidget form = (PdfFormWidget) doc.getForm();
        
        //get the form widget collection
        PdfFormFieldWidgetCollection formWidgetCollection = form.getFieldsWidget();

        //loop through the widget collection and fill each field with value
        for (int i = 0; i < formWidgetCollection.getCount(); i++) {
        	
            PdfField field = formWidgetCollection.get(i);         
            if (field instanceof PdfTextBoxFieldWidget) {
                PdfTextBoxFieldWidget textBoxField = (PdfTextBoxFieldWidget) field;
                textBoxField.setText("Kaila Smith");
            }         
            if (field instanceof PdfRadioButtonListFieldWidget) {
                PdfRadioButtonListFieldWidget radioButtonListField = (PdfRadioButtonListFieldWidget) field;
                radioButtonListField.setSelectedIndex(1);
            }
            if (field instanceof PdfListBoxWidgetFieldWidget) {
                PdfListBoxWidgetFieldWidget listBox = (PdfListBoxWidgetFieldWidget) field;
                listBox.setSelectedIndex(0);
            }
            if (field instanceof PdfCheckBoxWidgetFieldWidget) {
                PdfCheckBoxWidgetFieldWidget checkBoxField = (PdfCheckBoxWidgetFieldWidget) field;
                switch(checkBoxField.getName()){
                case "checkbox1":
                	checkBoxField.setChecked(true);
                	break;
                case "checkbox2":
                	checkBoxField.setChecked(true);
                	break;
                }
            }
            if (field instanceof PdfComboBoxWidgetFieldWidget) {
                PdfComboBoxWidgetFieldWidget comboBoxField = (PdfComboBoxWidgetFieldWidget) field;
                comboBoxField.setSelectedIndex(1);
            }
        }
        
        //Save the file
        doc.saveToFile("FillFormFields.pdf", FileFormat.PDF);
    }

}