Planning our
Enhanced XML with DTD
Let's start with a simple DTD file with the element tags we described before.
Once you have that working, go ahead and add the attribute tags.
- We need to make a few changes to our program as well.
- Set validaton on by passing the boolean true to the setValidating method of the DocumentBuilderFactory.
- Also, pass true to the setIgnoringContentElementWhitespace method of DocumentBuilderFactory.
- Now we need to make an error handler class, in case the parser throws an Exception.
- This error handler must implement interface ErrorHandler, and provide definitions for its methods.
- It can be a public class if you wish, but an inner class will be fine for our purposes.
- Once you have created and instantiated this class, you must add it to the DocumentBuilder with the setErrorHandler method.
- In the DTD line of the XML file, the word that follows DATASOURCE must be the root element of the file.
<!DOCTYPE database SYSTEM "datasource.dtd">