Parsing, Creating, and Transforming XML Documents - Beginning Java 7 - page 971

ateXMLStreamReader(Reader reader) . These methods throw
javax.xml.stream.XMLStreamException whenthestream-basedreadercan-
not be created.
The following example creates a stream-based reader whose source is a file named
recipe.xml :
Reader reader = new FileReader("recipe.xml");
XMLStreamReader xmlsr = xm-

lif.createXMLStreamReader(reader);
The low-level XMLStreamReader interface offers the most efficient way to read
XML data with StAX. This interface's boolean hasNext() method returns true
whenthereisanextinfosetitemtoobtain;otherwise,itreturnsfalse.The int next()
methodadvancesthecursorbyoneinfosetitemandreturnsanintegercodethatidenti-
fies this item's type.
Instead of comparing next() 's return value with an integer value, you would
compare this value against a javax.xml.stream.XMLStreamConstants in-
fosetconstant,suchas START_ELEMENT or DTD — XMLStreamReader extendsthe
XMLStreamConstants interface.

Note You can also obtain the type of the infoset item that the cursor is pointing
to by calling XMLStreamReader 's int getEventType() method. Specifying
“ Event ”inthenameofthismethodisunfortunatebecauseitconfusesstream-based
readers with event-based readers.

Thefollowingexampleusesthe hasNext() and next() methodstocodifyapars-
ing loop that detects the start and end of each element:
while (xmlsr.hasNext())
{

switch (xmlsr.next())
{

case XMLStreamReader.START_ELEMENT: // Do something
at element start.

break;
case XMLStreamReader.END_ELEMENT : // Do something
at element end.
}

}