How to read XML file in Java - JSP
Hi there, this is my first post and first tutorial. So I will like to show how to read XML file using JSP.
There are many ways how to read XML files. But I will show you how to read XML file using DOM XML Parser. DOM will parser the entire XML document and load it into memory.
There are many ways how to read XML files. But I will show you how to read XML file using DOM XML Parser. DOM will parser the entire XML document and load it into memory.
Since DOM will load XML document into memory, it will cost performance of the system if the xml document contains lot of data. Please consider SAX parser as solution if you have lot of data in xml document.
XML file example
this will be an example of XML document.<?xml version="1.0" encoding="UTF-8"?>
<domparsersys>
<web-page id="001">
<page-name>index.jsp</page-name>
<roles>*</roles>
</web-page>
<web-page id="002">
<page-name>usermanager.jsp</page-name>
<roles>ADMINISTRATOR</roles>
</web-page>
</domparsersys>
JSP file
<%@page import="org.w3c.dom.Element"%>
<%@page import="org.w3c.dom.Node"%>
<%@page import="org.w3c.dom.NodeList"%>
<%@page import="org.w3c.dom.Document"%>
<%@page import="javax.xml.parsers.DocumentBuilder"%>
<%@page import="javax.xml.parsers.DocumentBuilderFactory"%>
<%@page import="java.io.File"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title></title>
</head>
<body>
<h1>Read Xml using DOM parser</h1>
<%
try {
File xmlFile = new File("D:/Data/example1.xml");
DocumentBuilderFactory docBuilderFac = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFac.newDocumentBuilder();
Document doc = docBuilder.parse(xmlFile);
//optional, but
//read this - http://stackoverflow.com/questions/13786607/normalization-in-dom-parsing-with-java-how-does-it-work
doc.getDocumentElement().normalize();
System.out.println("Root element :" + doc.getDocumentElement().getNodeName());
NodeList nList = doc.getElementsByTagName("web-page");
for (int temp = 0; temp < nList.getLength(); temp++) {
Node nNode = nList.item(temp);
System.out.println("<br/>Current Element :" + nNode.getNodeName());
if (nNode.getNodeType() == Node.ELEMENT_NODE) {
Element eElement = (Element) nNode;
out.println("<br/>Page id : " + eElement.getAttribute("id"));
out.println("<br/>Page Name : " + eElement.getElementsByTagName("page-name").item(0).getTextContent());
out.println("<br/>Roles : " + eElement.getElementsByTagName("roles").item(0).getTextContent());
}
}
} catch (Exception ex){
out.println(ex.getMessage());
}
%>
</body>
</html>
Output
Page id : 001
Page Name : index.jsp
Roles : *
Page id : 002
Page Name : usermanager.jsp
Roles : ADMINISTRATOR
.bmp)
