Examples-GroupDocs.Metadata-for-Java
// initialize DocFormat
DocFormat docFormat = new DocFormat(Common.mapSourceFilePath(path));
// get document properties
DocMetadata properties = docFormat.getDocumentProperties();
// update built-in properties
properties.setAuthor("test author");
properties.setCompany("test company");
properties.setManager("test manager");
// commit changes
docFormat.save(Common.mapDestinationFilePath(outputPath));