Free Java Twitter API Tutorial, Develop J2EE application with Twitter APIs
Update Twitter status from your java application, Send direct private messages to your twitter followers from your java application, Follow other Twitter users directly from your J2EE application, retrieve list of your followers, retrieve full Twitter user details and GEO-location.
Implement single sign on (SSO) in your web application using Twitter user.OAuth - is a technology that enables applications to access the Twitter platform on your behalf without ever asking you directly for your password.
VIC Consulting Twitter API Library (java doc)
Developing application interacting with Twitter API is now very simple. Below is example of updating Twitter user status.
1) Login to your Twitter user and go to http://twitter.com/oauth_clients/ to see registered applications or register one. Get consumKey and consumSecret.
2) Write few lines of code as shown below:
VICTwitter vicTwitter = new VICTwitter(consumKey, consumSecret,new AccessToken(token,tokenSecret));
vicTwitter.updateStatus("Hello Twitter world");
vicTwitter.shutdown();