This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Note that there is a difference btween testing for well-formedness (which is what closing and properly matching tags is all about) and validation (which requires a schema of some kind to test the XML against). Start reading here: https://www.coderanch.com/how-to/java/XmlFaq