// For complete examples and data files, please go to https://github.com/groupdocs-signature/GroupDocs.Signature-for-Java
// setup Signature configuration
SignatureConfig signConfig = CommonUtilities.getConfiguration();
// instantiating the conversion handler
SignatureHandler<String> handler = new SignatureHandler<String>(signConfig);
// setup options with text of signature
SignOptions signOptions = new CellsSignTextOptions("John Smith");
// specify load options
LoadOptions loadOptions = new LoadOptions();
loadOptions.setPassword("1234567890");
// specify save options
SaveOptions saveOptions = new SaveOptions();
saveOptions.setOutputType(OutputType.String);
saveOptions.setOutputFileName("signed_output.xls");
// sign document
String signedPath = handler.<String>sign(CommonUtilities.getStoragePath(fileName), signOptions, loadOptions, saveOptions);
System.out.println("Signed file path is: " + signedPath);