Developing Web Applications has never been easier with the new generation Java open source tools. Youll be amazed at how fast you can have a ready-for-production AJAX web application up and running from scratch.In this book youll learn OpenXava, JPA, Eclipse, PostgreSQL, JUnit, HtmlUnit, Hibernate Validator framework, Liferay, etc. More importantly, youre going to learn techniques to solve both common and advanced cases that youll face developing business applications.The book starts with an overview of OpenXava framework, JPA technology and Java annotations. Then it walks readers through the creation of an Invoicing application using Eclipse, Tomcat and PostgreSQL. This application will evolve, adding complex domain model with inheritance, business logic, creation of custom hibernate validator, calling REST web services, automated testing with HtmlUnit, navigation and security by means of Liferay portal, etc.