External Documentation
From Salespoint 5
Java
Java 1.8 Javadoc
Spring MVC
Introduction to Spring Web MVC framework
Spring Expression Language (SpEL)
Spring Javadoc
Spring Framework Reference Documentation
Validation
Validation, Data Binding, and Type Conversion
Using Bean Validation
Hibernate Validator
Security
Spring Security 1
Spring Security 2
Expression-Based Access Control
Thymeleaf
Thymeleaf
Thymeleaf - Spring Security 3 integration module
JPA
Introduction to the Java Persistence API
javax.persistence Javadoc
Wikibooks - Java Persistence
Google JPA tutorial
