Elliotte Rusty Harold
Addison Wesley, 2002
Chapters 3-4:
Chapter 3, Writing XML with Java: http://www.cafeconleche.org/books/xmljava/chapters/ch03.html
Chapter 4, Converting Flat Files to XML: http://www.cafeconleche.org/books/xmljava/chapters/ch04.html
For streams and readers and writers:
Java I/O
Elliotte Rusty Harold
O'Reilly & Associates, 1999
ISBN: 1-56592-485-1
For well-formedness rules and such: XML in a Nutshell, third edition
Elliotte Rusty Harold and W. Scott Means
O'Reilly & Associates, 2004
ISBN 0-596-00764-7