Reading XML based on DTD

Question

HI All
i need a solution.
if we have a dtd file and a xml file and read the file using SAX i am able to read it where i use the startElement() and endElement() and in these i will use a hardcoded my tag names so that upon reaching this tag name i do something or print.
THis is fine.
But what if i have different DTDs and their corresponding XMLs
Can i read an XML by parsing first a DTD,getting the elements from the DTD and use those element names in the XML parsing by SAX.
That is i need a generic program where given a DTD and XML, i can parse the XML based on DTD
Is this possiblew with SAX or any other parser.
if so how.
i found that if i read 10 XML files from a parser. i can do that only if all are of the same DTD type.
but can i have 10 XML with each one with different DTD and even then use a single program to read all the files
Please help me
Thanks
Vijay Sunder

Answer 1

Normally, XML is done for writing XML instances, respecting a specific DTD or SCHEMA.
In the XML content you can set the DTD for the instance. So, instances can have reference to a DTD, not necessarily the same, of sure.
In that case, the PARSER is responsible for validating the instance against the defined DTD. Simply, be careful to locate the right DTD for each instance.
There is a very good tutorial, and short, here [http://java.sun.com/j2ee/1.4/docs/tutorial/doc/] and go to "Chapter 2: Understanding XML". You will learn how to parse a XML document, how to validate its content...
Naturally, a Java program can read multiple XML documents, extract valuable data for your stuff. For example transform a echo.java source explained in the tutorial, for handling multiple input document which is your need, and you will experience that this code can parse different documents having different DTD references.