Special Edition Using Java™ 2 Enterprise Edition

Why XML Is Good for Data Exchange

One of the most promising aspects of XML is that it makes it easier for companies to exchange data. In the past, companies had to develop proprietary data formats for exchanging data. Obviously, you must still define a data format when you use XML, but the benefit of XML is that it provides a standard format for defining the data format! Now, instead of working from some free-form text document that describes a proprietary file format, you can read a Document Type Definition (DTD) to understand the format of a document.

Although a DTD lets you convey the overall structure of a document, it doesn't let you specify data types. Another flaw of DTDs is that they aren't valid XML documents. You must use a custom parser ...