I have found multiple StackOverflow questions dealing with how to create or edit Google Doc spreadsheets using the Google Spreadsheets API, or older API\'s. However, this S
Google-apps-script will also create Spreadsheets and let you add data. See https://developers.google.com/apps-script/reference/spreadsheet/spreadsheet-app It can do more than the GData api, i.e. google-apps-script can set cell fonts/colors etc.
But depends on your needs, GData is low level in style, and so I find it faster. There is a simple google GData demo CellDemo.java. http://gdata-java-client.googlecode.com/svn-history/r51/trunk/java/sample/spreadsheet/cell/CellDemo.java It show off the Gdata Spreadsheets API features.