The javax.xml.parsers.SAXParserFactory Class

Super Class : java.lang.Object.

Public Members

Overview

 This is an abstract class. Defines a factory API that enables applications to configure and obtain a SAX based parser to parse XML documents. This class is not thread safe and user should take care regarding creation of DocumentBuilderFactory and it is suggested to have one instance per Thread and user should ensure that the same instance is not used across more than one thread to create SAXParser. This class is generally used to get javax.xml.parsers.SAXParser.

Application code does not deal directly with specific parse implementation such as Xerces or Crimson. Instead you write code against abstract classes provided by JAXP apis. This level of indirection allows you to choose and pick among different implementation without even recompiling your application.

Method Overviews

Important methods of this class are newInstance(),   newSAXParser(), setNamespaceAware(boolean awareness) and setValidating(boolean validating).

Example of newInstance()

This method is used to create a new concrete implementation of this class. This is a abstract class and newInstance method uses the lookup method to load appropriate SAXParserFactory. Following lookup procedure is used create a concrete implementation of SAXParserFactory.

·        Use the value of javax.xml.parsers. SAXParserFactory system property.

You can set the system property as {your factory class} = your factory class impl (It  may be org.apache.crimson.jaxp.SAXParserFactoryImpl or org.apache.xerces.jaxp.SAXParserFactoryImpl). You can set this system property to any api implementation depending upon your requirement.

·        IfJRE/lib/jaxp.properties exists, then look for a javax.xml.parsers.SAXParserFactory = Implementation entry in the file.

·        Use a JAR file service provider to look for a file called META-INF/services/ javax.xml.parsers.SAXParserFactory in any jar file on the CLASSPATH.

·        Use default javax.xml.parsers. SAXParserFactory instance(org.apache.crimson.jaxp.SAXParserFactoryImpl will be used as a default implementation).

By default, it loads org.apache.crimson.jaxp. SAXParserFactoryImpl instance. You can find this class in lib/rt.jar file.

1)     newSAXParser(). This method creates an instance of javax.xml.parsers.SAXParser using the currently configured factory parameters.

2)     setValidating(boolean). This method is used to validate an xml document during parsing. By default it is false.

3)     setNamespaceAware(boolean). This method is used to provide namespace aware for the parser and by default it is false.

Example for implementation of newInstance() method

import javax.xml.parsers.SAXParserFactory;

import javax.xml.parsers.SAXParser;

public class SaxParserFactoryImplementation {

  public SaxParserFactoryImplementation() {

    SAXParserFactory factory = SAXParserFactory.newInstance();

   }

}

Example for implementation of newSAXParser() method

import javax.xml.parsers.SAXParserFactory;

import javax.xml.parsers.SAXParser;

public class SaxParserFactoryImplementation {

  public SaxParserFactoryImplementation() {

    SAXParserFactory factory = SAXParserFactory.newInstance();

    try{

      SAXParser saxParser = factory.newSAXParser();

    }catch(javax.xml.parsers.ParserConfigurationException e){

      e.printStackTrace();

    }

   }

}