Fastest and optimized way to read the xml

Question

I have this below XML file

  Kiran
  Pai
  22
         


        

Answer 1

Using ReadAndPrintXMLFileWithStAX below, when I compare with ReadAndPrintXMLFileWithSAX from the answer given by gontard the StAX approach is faster. My test involved running both sample code 500000 times on JDK 1.7.0_07 for the Mac.

ReadAndPrintXMLFileWithStAX:  103 seconds
ReadAndPrintXMLFileWithSAX:   125 seconds

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ReadAndPrintXMLFileWithStAX (using Java SE 7)

Below is a more optimized StAX (JSR-173) example using XMLStreamReader instead of 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");
    }

}

Output

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