How do you know whether your XML document is well-formed and valid? One way is to check it with an XML validator, and you have plenty to choose from. Validators are packages that will check your XML and give you feedback. For example, if you have the XML for Java parser from IBM's AlphaWorks installed, you can use the DOMWriter example as a complete XML validator. Let's say you wanted to check this document, greeting.xml:
<?xml version="1.0" encoding="UTF-8"?> <DOCUMENT> <GREETING> Hello From XML </GREETING> <MESSAGE> Welcome to the wild and woolly world of XML. </MESSAGE> </DOCUMENT>
To do this, you'd set things up for the XML4J package (we'll see how to do so later in the book) and run the DOMWriter sample on it, like this: ...