Parsing XML files in JAVA

1. Use the SAX parser for large files http://stackoverflow.com/questions/15132390/parsing-large-xml-documents-in-java
2. http://elegantcode.com/2010/08/07/dont-parse-that-xml/
3. The DOM Parser loads the complete XML content into a Tree structure. And we iterate through the Node and NodeList to get the content of the XML
4. SAX Parser is different from the DOM Parser where SAX parser doesn’t load the complete XML into the memory, instead it parses the XML line by line triggering different events as and when it encounters different elements like: opening tag, closing tag, character data, comments and so on. This is the reason why SAX Parser is called an event based parser.
5. StAX stands for Streaming API for XML and StAX Parser is different from DOM in the same way SAX Parser is. StAX parser is also in a subtle way different from SAX parser.
   The SAX Parser pushes the data but StAX parser pulls the required data from the XML.
   The StAX parser maintains a cursor at the current position in the document allows to extract the content available at the cursor whereas SAX parser issues events as and when certain data is encountered.

XMLInputFactory and XMLStreamReader are the two class which can be used to load an XML file. And as we read through the XML file using XMLStreamReader, events are generated in the form of integer values and these are then compared with the constants inXMLStreamConstants.

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