Plus rapide et optimisé de façon à lire le fichier xml

À l'aide de ReadAndPrintXMLFileWithStAX ci-dessous, quand je compare avec ReadAndPrintXMLFileWithSAX de la réponse donnée par gontard le StAX approche est plus rapide. Mon test a porté sur l'exécution à la fois un exemple de code 500000 fois sur JDK 1.7.0_07 pour le Mac.

ReadAndPrintXMLFileWithStAX:  103 seconds
ReadAndPrintXMLFileWithSAX:   125 seconds

ReadAndPrintXMLFileWithStAX (à l'aide de Java SE 7)

Ci-dessous est un plus optimisé StAX (JSR-173) exemple d'utilisation de XMLStreamReader au lieu de XMLEventReader.

import java.io.FileInputStream;
import java.io.InputStream;
import javax.xml.stream.*;
public class ReadAndPrintXMLFileWithStAX {
public static void main(String argv[]) throws Exception {
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
InputStream in = new FileInputStream("book.xml");
XMLStreamReader streamReader = inputFactory.createXMLStreamReader(in);
streamReader.nextTag(); //Advance to "book" element
streamReader.nextTag(); //Advance to "person" element
int persons = 0;
while (streamReader.hasNext()) {
if (streamReader.isStartElement()) {
switch (streamReader.getLocalName()) {
case "first": {
System.out.print("First Name : ");
System.out.println(streamReader.getElementText());
break;
}
case "last": {
System.out.print("Last Name : ");
System.out.println(streamReader.getElementText());
break;
}
case "age": {
System.out.print("Age : ");
System.out.println(streamReader.getElementText());
break;
}
case "person" : {
persons ++;
}
}
}
streamReader.next();
}
System.out.print(persons);
System.out.println(" persons");
}
}

Sortie

First Name : Kiran
Last Name : Pai
Age : 22
First Name : Bill
Last Name : Gates
Age : 46
First Name : Steve
Last Name : Jobs
Age : 40
3 persons

OriginalL'auteur Blaise Doughan

Un Stax Exemple

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
public class ReadAndPrintXMLFile {
public static void main(String argv []) {
String inputFile = "c:/source/book.xml";
try {
//First create a new XMLInputFactory
XMLInputFactory inputFactory = XMLInputFactory.newInstance();
//Setup a new eventReader
InputStream in = new FileInputStream(inputFile);
XMLEventReader eventReader = inputFactory.createXMLEventReader(in);
//Read the XML document
while (eventReader.hasNext()) {
XMLEvent event = eventReader.nextEvent();
if (event.isStartElement()) {
StartElement startElement = event.asStartElement();
if (startElement.getName().getLocalPart().equals("first")) {
event = eventReader.nextEvent();
StringBuilder fName = new StringBuilder();
while (!event.isEndElement()) {
fName.append(event.asCharacters().getData());
event = eventReader.nextEvent();
}
System.out.println("First Name : " + fName);
event = eventReader.nextEvent();
continue;
}
if (startElement.getName().getLocalPart().equals("last")) {
event = eventReader.nextEvent();
StringBuilder lName = new StringBuilder();
while (!event.isEndElement()) {
lName.append(event.asCharacters().getData());
event = eventReader.nextEvent();
}
System.out.println("Last Name : " + lName);
event = eventReader.nextEvent();
continue;
}
if (startElement.getName().getLocalPart().equals("age")) {
event = eventReader.nextEvent();
StringBuilder age = new StringBuilder();
while (!event.isEndElement()) {
age.append(event.asCharacters().getData());
event = eventReader.nextEvent();
}
System.out.println("Age : " + age);
event = eventReader.nextEvent();
continue;
}
}
}
} catch (FileNotFoundException e) {
System.out.println("File not Found: " + inputFile);
} catch (XMLStreamException e) {
e.printStackTrace();
}
}
}

Sortie:

First Name : Kiran
Last Name : Pai
Age : 22
First Name : Bill
Last Name : Gates
Age : 46
First Name : Steve
Last Name : Jobs
Age : 40

OriginalL'auteur Mike