XML validation using XSD

I was using JAXB for reading one configuration file and before unmarshall, I want to validate the document. To do this we need to know two things:

1. How to link xml document with schema
2. How to configure SAX/DOM parser to use the schema and validate
   

Below are the excellent resources I found explaining above steps:

1. Link schema with xml
2. Configure parser to use schema for validation

Creating XSD from XML

Recently we had a requirement to build a data model at the back-end for a web front-end, which is based on an xml file.  Once decided to use jaxb, we realised we didn't have the schema definition but only have xml file.  So started my search for creating xsd from xml.  I found couple of on-line links for xsd creation and other applications supporting this feature.

On-line links

http://www.flame-ware.com/xml2xsd/
http://www.xmlforasp.net/codeSection.aspx?csID=79
http://www.hitsw.com/xml_utilites/

Others
IBM RAD can generate xsd from xml, you need to add xml file as part of some project.
Microsoft also provides a tool xsd.exe, but I guess you need .NET framework for this to work.
Another open-source tool trang.