T
HE
SAX API
9
method can also take a variety of other input sources, including an
InputStream
object, a URL, and an
InputSource
object.
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser saxParser = factory.newSAXParser();
saxParser.parse("priceList.xml", handler);
The result of calling the method
parse
depends, of course, on how the methods
in
handler
were implemented. The SAX parser will go through the file
priceList.xml
line by line, calling the appropriate methods. In addition to the
methods already mentioned, the parser will call other methods such as
start-
Document
,
endDocument
,
ignorableWhiteSpace
, and
processingInstructions
,
but these methods still have their default implementations and thus do nothing.
The following method definitions show one way to implement the methods
characters
and
startElement
so that they find the price for Mocha Java and
print it out. Because of the way the SAX parser works, these two methods work
together to look for the
name
element, the characters "Mocha Java", and the
price
element immediately following Mocha Java. These methods use three
flags to keep track of which conditions have been met. Note that the SAX parser
will have to invoke both methods more than once before the conditions for print-
ing the price are met.
public void startElement(..., String elementName, ...){
if(elementName.equals("name")){
inName = true;
} else if(elementName.equals("price") && inMochaJava ){
inPrice = true;
inName = false;
}
}
public void characters(char [] buf, int offset, int len) {
String s = new String(buf, offset, len);
if (inName && s.equals("Mocha Java")) {
inMochaJava = true;
inName = false;
} else if (inPrice) {
System.out.println("The price of Mocha Java is: " + s);
inMochaJava = false;
inPrice = false;
}
}
}
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