XML Programming: TrAX

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XML Programming TrAX

• Andy Clark

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Java API for XML Processing

• Standard Java API for loading, creating,
  accessing, and transforming XML documents
• JAXP parsing
• Supports DOM and SAX
• TrAX transformation
• Generic transformation framework
• Java standard extension (i.e. javax package)
• Defined by Sun JCP

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Transformation API for XML

• Transformation framework
• Allows generic transformation from one form to
  another
• Examples
• Serializers
• XSLT processors
• etc

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javax.xml.transform (1 of 2)

• Transformation
• Transformer, TransformerFactory
• Templates
• Input and Output
• Source
• Result

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javax.xml.transform (2 of 2)

• Transformer control
• ErrorListener
• SourceLocator, URIResolver
• OutputKeys
• Other
• TransformerConfigurationException
• TransformerException
• TransformerFactoryConfigurationError

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Input and Output

• javax.xml.transform.stream
• StreamSource
• StreamResult
• javax.xml.transform.dom
• DOMSource, DOMResult
• DOMLocator
• javax.xml.transform.sax
• SAXSource, SAXResult
• SAXTransformerFactory
• TransformerHandler, TemplatesHandler

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Stream Input and Output

• StreamSource
• Specifies document stream to parse
• StreamResult
• Specifies stream for serialization of document
• OutputKeys controls serialization settings

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DOM/SAX Input and Output

• Document Object Model
• DOMSource
• Specifies document or node to process
• DOMResult
• Specifies document factory for new nodes
• Simple API for XML
• SAXSource
• Specifies XMLReader to parse document
• SAXResult
• Specifies handler for generated events

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Transform Document (1 of 3)

• Identity transform
• Get instance of transformer factory
• TransformerFactory factory TransformerFactory.ne
  wInstance()
• Create transformer
• Transformer transformer factory.newTransformer()
  
• Create input and output
• Source source new StreamSource(document.xml)
• Result result new StreamResult(System.out)
• Transform document
• transformer.transform(source, result)

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Transform Document (2 of 3)

• Transform with stylesheet (1 of 2)
• Get instance of transformer factory
• TransformerFactory factory TransformerFactory.ne
  wInstance()
• Create templates
• Source templatesSource new StreamSource(style.x
  sl)
• Templates templates factory.newTemplates(templat
  esSource)
• Create transformer
• Transformer transformer templates.newTransformer
  ()

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Transform Document (3 of 3)

• Transform with Stylesheet (2 of 2)
• Create input and output
• Source source new StreamSource(document.xml)
• Result result new StreamResult(System.out)
• Transform document
• transformer.transform(source, result)

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Error Handling and Entity Resolution

• Transformer
• Can set a TrAX ErrorListener
• Can set a TrAX URIResolver
• URIResolver
• Called when reference to multiple documents
• Passed base and literal system identifiers of
  resource
• Example XPath document(book.xml)/book/title
• Returns a TrAX Source
• Note This is super cool because it means that
  you can cache (or generate) documents in memory.

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Useful Links

• JAXP
• http//java.sun.com/xml/
• Apache Xalan XSLT Processor
• http//xml.apache.org/xalan-j/

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XML Programming TrAX

• Andy Clark