public abstract int nextTag () throws XMLStreamException

Skips any white space (isWhiteSpace() returns true), COMMENT, or PROCESSING_INSTRUCTION, until a START_ELEMENT or END_ELEMENT is reached. If other than white space characters, COMMENT, PROCESSING_INSTRUCTION, START_ELEMENT, END_ELEMENT are encountered, an exception is thrown. This method should be used when processing element-only content seperated by white space.
Precondition: none
Postcondition: the current event is START_ELEMENT or END_ELEMENT and cursor may have moved over any whitespace event.
Essentially it does the following (implementations are free to optimized but must do equivalent processing):

 int eventType = next();
 while((eventType == XMLStreamConstants.CHARACTERS && isWhiteSpace()) // skip whitespace
 || (eventType == XMLStreamConstants.CDATA && isWhiteSpace())
 // skip whitespace
 || eventType == XMLStreamConstants.SPACE
 || eventType == XMLStreamConstants.PROCESSING_INSTRUCTION
 || eventType == XMLStreamConstants.COMMENT
 ) {
 eventType = next();
 }
 if (eventType != XMLStreamConstants.START_ELEMENT && eventType != XMLStreamConstants.END_ELEMENT) {
 throw new String XMLStreamException("expected start or end tag", getLocation());
 }
 return eventType;
 

Returns:  the event type of the element read (START_ELEMENT or END_ELEMENT)

Exceptions:

XMLStreamException		if the current event is not white space, PROCESSING_INSTRUCTION, START_ELEMENT or END_ELEMENT
NoSuchElementException		if this is called when hasNext() returns false