JDK Tutorials - Herong's Tutorial Examples - v6.32, by Herong Yang
DOMValidator.java - XML DTD Validation with DOM
This section provides a tutorial example on how to write a DTD validator using DOM classes in JDK. The validator can validate an XML file against the specified DTD statements.
JDK offers a document builder interface, javax.xml.parsers.DocumentBuilder, to represent classes that can parse XML files into document objects described in the Document Object Model (DOM). See my notes on DOM for more details.
The document builder also supports DTD validation during the parsing process. To do this:
Here is a sample program, DOMValidator.java, that shows you how to use a document builder class to validate XML files against the specified DTD statements.
/* DOMValidator.java * Copyright (c) HerongYang.com. All Rights Reserved. */ import java.io.File; import java.io.IOException; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.ParserConfigurationException; import org.w3c.dom.Document; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; import org.xml.sax.ErrorHandler; import org.xml.sax.helpers.DefaultHandler; class DOMValidator { public static void main(String[] args) { try { File x = new File(args[0]); DocumentBuilderFactory f = DocumentBuilderFactory.newInstance(); f.setValidating(true); // Default is false DocumentBuilder b = f.newDocumentBuilder(); // ErrorHandler h = new DefaultHandler(); ErrorHandler h = new MyErrorHandler(); b.setErrorHandler(h); Document d = b.parse(x); } catch (ParserConfigurationException e) { System.out.println(e.toString()); } catch (SAXException e) { System.out.println(e.toString()); } catch (IOException e) { System.out.println(e.toString()); } } private static class MyErrorHandler implements ErrorHandler { public void warning(SAXParseException e) throws SAXException { System.out.println("Warning: "); printInfo(e); } public void error(SAXParseException e) throws SAXException { System.out.println("Error: "); printInfo(e); } public void fatalError(SAXParseException e) throws SAXException { System.out.println("Fatal error: "); printInfo(e); } private void printInfo(SAXParseException e) { System.out.println(" Public ID: "+e.getPublicId()); System.out.println(" System ID: "+e.getSystemId()); System.out.println(" Line number: "+e.getLineNumber()); System.out.println(" Column number: "+e.getColumnNumber()); System.out.println(" Message: "+e.getMessage()); } } }
See the next section on how to test this DTD validator.
Table of Contents
Date, Time and Calendar Classes
Date and Time Object and String Conversion
Number Object and Numeric String Conversion
Locales, Localization Methods and Resource Bundles
Calling and Importing Classes Defined in Unnamed Packages
HashSet, Vector, HashMap and Collection Classes
Character Set Encoding Classes and Methods
Encoding Conversion Programs for Encoded Text Files
Datagram Network Communication
DOM (Document Object Model) - API for XML Files
►DTD (Document Type Definition) - XML Validation
►DOMValidator.java - XML DTD Validation with DOM
SAXValidator.java - XML DTD Validation with SAX
XSD (XML Schema Definition) - XML Validation
XSL (Extensible Stylesheet Language)
Message Digest Algorithm Implementations in JDK
Private key and Public Key Pair Generation
PKCS#8/X.509 Private/Public Encoding Standards
Digital Signature Algorithm and Sample Program
"keytool" Commands and "keystore" Files
KeyStore and Certificate Classes
Secret Key Generation and Management
Cipher - Encryption and Decryption
The SSL (Secure Socket Layer) Protocol
SSL Socket Communication Testing Programs