Google provides a rich set of libraries to access their services. The Documents List Data API provides access to the Google Documents service:
The documentation describes how to make raw HTTP requests to access data. You can also download the Java client library:
The developer's guide provides several useful examples to get you started:
The Javadoc can be found here:
Finally, in order to run a sample application to upload a document, you must have the following jars in your classpath:
You also need to include mail.jar and activation.jar from the Java Mail library and the Activation Framework.