How to parse xml file in java?

Question

I am parsing xml file in java. I am getting SEVERE: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog. exception.

Answer 1

Here is xml file Stocks.xml which contains some stocks and there price, quantity we will use this in our xml parsing example in Java.

<?xml version="1.0" encoding="UTF-8"?>
    <stocks>
           <stock>
                  <symbol>Citibank</symbol>
                  <price>100</price>
                  <quantity>1000</quantity>
           </stock>
           <stock>
                  <symbol>Axis bank</symbol>
                  <price>90</price>
                  <quantity>2000</quantity>
           </stock>
    </stocks>

Here is a code example of parsing above xml file in Java using DOM parser:

import java.io.File;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class DOMExampleJava {

public static void main(String args[]) {
try {

File stocks = new File("Stocks.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(stocks);
doc.getDocumentElement().normalize();

System.out.println("root of xml file" + doc.getDocumentElement().getNodeName());
NodeList nodes = doc.getElementsByTagName("stock");
System.out.println("==========================");

for (int i = 0; i < nodes.getLength(); i++) {
Node node = nodes.item(i);

if (node.getNodeType() == Node.ELEMENT_NODE) {
Element element = (Element) node;
System.out.println("Stock Symbol: " + getValue("symbol", element));
System.out.println("Stock Price: " + getValue("price", element));
System.out.println("Stock Quantity: " + getValue("quantity", element));
}
}
} catch (Exception ex) {
ex.printStackTrace();
}
}

private static String getValue(String tag, Element element) {
NodeList nodes = element.getElementsByTagName(tag).item(0).getChildNodes();
Node node = (Node) nodes.item(0);
return node.getNodeValue();
}

}

 Output:

root of xml file stocks
==========================
Stock Symbol: Citibank
Stock Price: 100
Stock Quantity: 1000
Stock Symbol: Axis bank
Stock Price: 90
Stock Quantity: 2000

This is the Procedure of parsing an Xml using Java