Validating xml against dtd in java
This is useful for adding constraints that are more easily checked in a Turing-complete language like Java than in a declarative language like the W3C XML Schema language.You can define a mini-schema language, write a quick implementation, and plug it into the validation layer.Typically, the URL is the namespace Uniform Resource Identifier (URI) for the schema language. However, you can install additional libraries that add support for these and other schema languages.The Java programming language isn't limited to a single schema factory.DTDs and XSD were normally accessed as configuration options in Simple API for XML (SAX), Document Object Model (DOM), and Java™ API for XML Processing (JAXP). Schematron might use the Transformations API for XML(Tr AX); and still other schema languages required programmers to learn still more APIs, even though they were performing essentially the same operation.
A single implementation usually supports only a subset of the numerous languages and models.When you pass a URI identifying a particular schema language to that know how to process your schema language.Then, install your JAR in one of these four locations.Programmers would be unhappy if they had only one programming language to choose from.Different languages suit different tasks better, and some tasks require more than one language. You can choose from a plethora of useful schema languages.