implements EventFilter, StreamFilter : StreamFilter « XML « Java Tutorial

1. Java Tutorial
2. XML
3. StreamFilter

import java.io.File;
import java.io.FileInputStream;

import javax.xml.stream.EventFilter;
import javax.xml.stream.StreamFilter;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.events.XMLEvent;

public class EventFilterExample {
  public static void main(String[] args) throws Exception {
    File file = new File("text.xml");

    XMLInputFactory inputFactory = XMLInputFactory.newInstance();
    XMLEventReader reader = inputFactory.createXMLEventReader(new FileInputStream(file));

    System.out.println("Unfiltered Count = " + countEvents(reader));

    reader = inputFactory.createXMLEventReader(new FileInputStream(file));

    EventFilter filter = new ElementOnlyFilter();
    reader = inputFactory.createFilteredReader(reader, filter);

    System.out.println("Filtered Count = " + countEvents(reader));
  }

  private static int countEvents(XMLEventReader reader) throws XMLStreamException {
    int counter = 0;
    while (reader.hasNext()) {
      reader.next();
      counter++;
    }
    return counter;
  }
}

class ElementOnlyFilter implements EventFilter, StreamFilter {
  public boolean accept(XMLEvent event) {
    return accept(event.getEventType());
  }

  public boolean accept(XMLStreamReader reader) {
    return accept(reader.getEventType());
  }

  private boolean accept(int eventType) {
    return eventType == XMLStreamConstants.START_ELEMENT
        || eventType == XMLStreamConstants.END_ELEMENT;
  }
}