Seems that Google has no Gmail API available, so I made a small Java library called Gmail4J. The library is designed to be extensible, allowing various implementations. Currently the only available implementation allows getting new unread messages from their RSS feed. That's not much, but it's a start.
Here is the example code (updated to conform with Gmail4J 0.2):
GmailClient client = new RssGmailClient();
GmailConnection connection = new HttpGmailConnection("user", "pass".toCharArray());
client.setConnection(connection);
final List<GmailMessage> messages = client.getUnreadMessages();
for (GmailMessage message : messages) {
System.out.println(message);
}
Next implementation will probably be based on JavaMail IMAP functionality. It should be able to do more than getting unread messages.
