StAX tiene sus raíces en una serie de APIs de tipo pull para XML incompatibles, más notablemente XMLPULL, los autores de la cual (Stefan Haustein y Aleksander Slominski) colaboraron con, entre otros, BEA Systems, Oracle, Sun y James Clark.

De la especificación final de la JSR-173 V1.0 (utilizada bajo el uso justo).

Cita:

La siguiente API de Java muestra los principales métodos para leer XML en el enfoque del cursor.

public interface XMLStreamReader { 
  public int next() throws XMLStreamException; 
  public boolean hasNext() throws XMLStreamException; 
  public String getText(); 
  public String getLocalName(); 
  public String getNamespaceURI(); 
  // ...otros métodos no mostrados
}

La parte de escritura de la API tiene métodos que corresponden a la parte de lectura para tipos de eventos “StartElement” y “EndElement”.

public interface XMLStreamWriter { 
  public void writeStartElement(String localName) throws XMLStreamException;
  public void writeEndElement() throws XMLStreamException; 
  public void writeCharacters(String text) throws XMLStreamException; 
  // ...otros métodos no mostrados
}

5.3.1 XMLStreamReader

Este ejemplo ilustra cómo crear una instancia de una fábrica de entrada, crear un lector e iterar sobre los elementos de un documento XML.

XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance(); 
XMLStreamReader xmlStreamReader = xmlInputFactory.createXMLStreamReader(...); 
while (xmlStreamReader.hasNext()) { 
    xmlStreamReader.next(); 
}

Modos complementarios para procesar XML en Java:

• Document Object Model (DOM), el primer modelo de procesamiento de XML basado en árbol, estandarizado e independiente del lenguaje/plataforma, modelos de árbol alternativos de Java incluyen JDOM, Dom4j y XOM.
• Simple API for XML (SAX), el estándar de la API XML de tipo push.
• Java XML Binding API (JAXB), trabaja sobre otro analizador (usualmente un analizador de streaming), une los datos contenidos a/en los objetos de Java.
• Streaming XML
• XQuery API for Java

Implementaciones Java

• Sun Java StAX XML Processor (enlace roto disponible en Internet Archive; véase el historial, la primera versión y la última). Open source. Ships as part of Sun Java Standard Edition 6 runtime.
• Reference Implementation (for JSR-173, API specification, under the Apache Software License)
• Woodstox Open source StAX implementation (LGPL or Apache license)
• Aalto is an ultra-high-performance parser (Apache license)

Utilidades y add-ons

• StAX-Utils Provides a set of utility classes that make it easy for developers to integrate StAX into their existing XML processing applications.
  • StAX-Utils includes classes to provide XML file indenting and formatting.
• StaxMate is a light-weight framework that builds on top of Stax API and provides more convenient nested/filtered cursor for reading xml, nested outputters for writing xml (with optional indentation) and other tools (build DOM from Stax sources, write to Stax destinations) for interoperability.

Analizadores construidos sobre StAX

• Apache Axiom is a light weight XML object model based on top of Stax and also provides lazy object building.
• Apache Pivot uses StAX for the serialization of user interface markup written in BXML.
• JavaFX 2.0 uses StAX for the serialization of user interface markup written in FXML.

Analizadores no estándar similares a StAX

• XPP Parser based on the very similar but older XMLPull API.
• kXML Archivado el 12 de febrero de 2014 en Wayback Machine. A Java Micro Edition parser that uses the XMLPull API.
• Javolution provides a real-time StAX-like implementation which does not force object creation (e.g. String) and has smaller effect on memory footprint/garbage collection (Note: to reduce object creation, most StAX implementations maintain lookup tables to retrieve and reuse frequently used String objects).
• The XmlReader class in Microsoft's .NET Framework is a pull-style XML parser.

Analizadores XML de tipo pull no Java

• Qt has XML parser (QXmlStreamReader) and writer (QXmlStreamWriter)
• irrXML is a simple and fast open source XML parser for C++
• LlamaXML is the XML C++ pull parser and writer
• libxml2 is the XML C parser and toolkit (MIT License)
• Expat is an XML parser library written in C

Artículos y recursos

• Introduction to StAX XML.com, Harold, Elliotte Rusty
• Java Streaming API for XML (Stax) - Tutorial
• JSR (#173)

Download JSR specification document as a pdf here: download now

• XMLPull Patterns Article on XML Pull (and StAX) design patterns by Aleksander Slominski.
• XMLPull.org
• StAX and Sax comparison.
• Using StAX with JAXB for efficiency
• StAX and Java eg. from DevX.com