Using XMLEventReader

The XMLEventReader API in the StAX event iterator API provides the means to map events in an XML stream to allocated event objects that can be freely reused, and the API itself can be extended to handle custom events.

XMLEventReader provides four methods for iteratively parsing XML streams:

• next: Returns the next event in the stream

• nextEvent: Returns the next typed XMLEvent

• hasNext: Returns true if there are more events to process in the stream

• peek: Returns the event but does not iterate to the next event

For example, the following code snippet illustrates the XMLEventReader method declarations:

package javax.xml.stream;
import java.util.Iterator;
public interface XMLEventReader extends Iterator {
    public Object next();
    public XMLEvent nextEvent() throws XMLStreamException;
    public boolean hasNext();
    public XMLEvent peek() throws XMLStreamException;
    ...
}

To read all events on a stream and then print them, you could use the following:

while(stream.hasNext()) {
    XMLEvent event = stream.nextEvent();
    System.out.print(event);
}

Reading Attributes

You can access attributes from their associated javax.xml.stream.StartElement, as follows:

public interface StartElement extends XMLEvent {
    public Attribute getAttributeByName(QName name);
    public Iterator getAttributes();
}

You can use the getAttributes method on the StartElement interface to use an Iterator over all the attributes declared on that StartElement.

Reading Namespaces

Similar to reading attributes, namespaces are read using an Iterator created by calling the getNamespaces method on the StartElement interface. Only the namespace for the current StartElement is returned, and an application can get the current namespace context by using StartElement.getNamespaceContext.