Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Exactly what I needed - great intro to Portlets

This book was exactly what I was looking for - an introduction to the Portlet (JSR 168) specification. The authors cover the portlet spec and discuss WSRP and SSO in addition. This book doesn't detail out the entire API, but hits on the highlights necessary to become familiar with portlets. Good, solid introduction to an API that suffers from a lack of exposition.