Difference SAXParserFactory XMLReaderFactory. Which one to choose?

问题

Both of them seem to have the same purpose (create a XMLReader). Some Tutorials contain the one, some the other.

SAXParserFactory:

http://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/SAXParserFactory.html
seems to be more configurable
more boiler-plate code
officially supported api

example code:

// SAXParserFactory
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
XMLReader reader = parser.getXMLReader();
reader.parse(new InputSource("document.xml"));

XMLReaderFactory:

http://docs.oracle.com/javase/7/docs/api/org/xml/sax/helpers/XMLReaderFactory.html
two lines less code
less configurable
comunity supported and comes with no waranty

example code:

// XMLReaderFactory
XMLReader xmlReader = XMLReaderFactory.createXMLReader();
xmlReader.parse(new InputSource("document.xml"));

question:

Are these the main differences or are there some i've overseen.

Which one should you choose?

回答1:

The main JAXP APIs are defined in the javax.xml.parsers package. That package contains vendor-neutral factory classes like the SAXParserFactory which give you a SAXParser.

The SAXParserFactory defines a factory API that enables applications to configure and obtain a SAX based parser to parse XML documents.

The SAXParser defines the API that wraps an XMLReader implementation class.
The Package org.xml.sax defines the basic SAX APIs.
The Java Runtime comes with a default implementation XMLReader

The SAXParserFactory hides details of which (SAX1) ParserFactory / (SAX2) XMLReaderFactory, ... from you.

If you want to be able to replace the default JAXP Parser by a different JAXP Parser (there may be a known incomapatibilty / bug in the default implementation) implementation you should use the vendor neutral SAXParserFactory.

If you know that your application will allways use a SAX2 XMLReader you may use the XMLReaderFactory.

回答2:

Elliotte Rusty Harold, who has written a book on XML processing in Java, once wrote:

SAXParserFactory [is] a hideous, evil monstrosity of a class that should 
be hung, shot, beheaded, drawn and quartered, burned at the stake, 
buried in unconsecrated ground, dug up, cremated, and the ashes tossed 
in the Tiber while the complete cast of Wicked sings "Ding dong, the 
witch is dead."  --Elliotte Rusty Harold on xml-dev

I wouldn't actually go that far (and if I did, I would try and make it grammatical). Like a lot of JAXP, it's not the most wonderful piece of design; but I do use it as the default way of getting a parser instance, if only because it's consistent with other parts of JAXP.

Historically, the two were developed in parallel. JAXP originally tried to add missing functionality to SAX1, but in parallel, SAX2 was coming along and filled in some of the gaps, so this particular gap got filled twice.

来源：https://stackoverflow.com/questions/10583536/difference-saxparserfactory-xmlreaderfactory-which-one-to-choose

标签

java

xml

sax

jaxp