JDK (Java Development Kit) Tutorials

∟XSD (XML Schema Definition) - XML Validation

∟Loading External XML Parsers with SAXParserFactory

This section provides a tutorial example on how to load external XML parsers using the SAXParserFactory.newInstance() method.

The Xerces-J package can also be loaded by the SAXParserFactory.newInstance() method. Here is my SAXValidator.java:

/**
 * SAXValidator.java
 * Copyright (c) 2002 by Dr. Herong Yang
 */
import java.io.File;
import java.io.IOException;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.DefaultHandler;
class SAXValidator {
   public static void main(String[] args) {
      String schemaFeature 
         = "http://apache.org/xml/features/validation/schema";
      try {
      	 File x = new File(args[0]);
         SAXParserFactory f = SAXParserFactory.newInstance();
         System.out.println(f.toString());
         f.setValidating(true);
         f.setFeature(schemaFeature,true);
         SAXParser p = f.newSAXParser();
         System.out.println(p.toString());
         DefaultHandler h = new MyErrorHandler();
         p.parse(x,h);
      } 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 extends DefaultHandler {
      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("Fattal 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());
      }
   }
}

Note that the schema feature to the SAXParserFactory object.

Now if you run the program with:

java -cp . SAXValidator dictrionary_invalid_xsd.xml

You will get:

org.apache.crimson.jaxp.SAXParserFactoryImpl@1004901
org.xml.sax.SAXNotRecognizedException: Feature: http://apache.org/xml
/features/validation/schema

Note that the crimson package was loaded from the J2SDK library, and it doesn't support XSD validation.

But if you run the program with:

java -cp .;\local\xerces-2_3_0\xercesImpl.jar SAXValidator
   dictrionary_invalid_xsd.xml

You will get:

org.apache.xerces.jaxp.SAXParserFactoryImpl@f72617
org.apache.xerces.jaxp.SAXParserImpl@173831b
...

Note that the xerces package was loaded, and XSD validation was performed.

Last update: 2006.

Table of Contents

 About This JDK Tutorial Book

 Downloading and Installing JDK 1.3.1 on Windows

 Downloading and Installing JDK 1.4.1 on Windows

 Downloading and Installing JDK 1.5.0 on Windows

 Downloading and Installing JDK 1.6.2 on Windows

 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

 Character Set Encoding Maps

 Encoding Conversion Programs for Encoded Text Files

 Socket Network Communication

 Datagram Network Communication

 DOM (Document Object Model) - API for XML Files

 SAX (Simple API for XML)

 DTD (Document Type Definition) - XML Validation

►XSD (XML Schema Definition) - XML Validation

 XML XSD Schema Validation with Xerces

 XML XSD Schema Validation Test Result

►Loading External XML Parsers with SAXParserFactory

 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 - Secret Key Encryption and Decryption

 The SSL (Secure Socket Layer) Protocol

 SSL Socket Communication Testing Programs

 SSL Client Authentication

 HTTPS (Hypertext Transfer Protocol Secure)

 References

 PDF Printing Version