What is the best/simplest way to read in an XML file in Java application? [closed]

Question

Currently our Java application uses the values held within a tab delimited *.cfg file. We need to change this application so that it now uses an XML file.

What is the best/simplest library to use in order to read in values from this file?

Answer 1

There are of course a lot of good solutions based on what you need. If it is just configuration, you should have a look at Jakarta commons-configuration and commons-digester.

You could always use the standard JDK method of getting a document :

import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document;  [...]  File file = new File("some/path"); DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); DocumentBuilder db = dbf.newDocumentBuilder(); Document document = db.parse(file); 

Answer 2

XML Code:

<?xml version="1.0"?> <company>     <staff id="1001">         <firstname>yong</firstname>         <lastname>mook kim</lastname>         <nickname>mkyong</nickname>         <salary>100000</salary>     </staff>     <staff id="2001">         <firstname>low</firstname>         <lastname>yin fong</lastname>         <nickname>fong fong</nickname>         <salary>200000</salary>     </staff> </company> 

Java Code:

import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.DocumentBuilder; import org.w3c.dom.Document; import org.w3c.dom.NodeList; import org.w3c.dom.Node; import org.w3c.dom.Element; import java.io.File;  public class ReadXMLFile {    public static void main(String argv[]) {     try {     File fXmlFile = new File("/Users/mkyong/staff.xml");     DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();     DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();     Document doc = dBuilder.parse(fXmlFile);     doc.getDocumentElement().normalize();      System.out.println("Root element :" + doc.getDocumentElement().getNodeName());     NodeList nList = doc.getElementsByTagName("staff");     System.out.println("----------------------------");      for (int temp = 0; temp < nList.getLength(); temp++) {         Node nNode = nList.item(temp);         System.out.println("\nCurrent Element :" + nNode.getNodeName());         if (nNode.getNodeType() == Node.ELEMENT_NODE) {             Element eElement = (Element) nNode;             System.out.println("Staff id : "                                + eElement.getAttribute("id"));             System.out.println("First Name : "                                + eElement.getElementsByTagName("firstname")                                  .item(0).getTextContent());             System.out.println("Last Name : "                                + eElement.getElementsByTagName("lastname")                                  .item(0).getTextContent());             System.out.println("Nick Name : "                                + eElement.getElementsByTagName("nickname")                                  .item(0).getTextContent());             System.out.println("Salary : "                                + eElement.getElementsByTagName("salary")                                  .item(0).getTextContent());         }     }     } catch (Exception e) {     e.printStackTrace();     }   } } 

Output:

----------------  Root element :company ----------------------------  Current Element :staff Staff id : 1001 First Name : yong Last Name : mook kim Nick Name : mkyong Salary : 100000  Current Element :staff Staff id : 2001 First Name : low Last Name : yin fong Nick Name : fong fong Salary : 200000 

I recommended you reading this: Normalization in DOM parsing with java - how does it work?

Example source.