How do I search for a keyword in a XML file using Java?

I would like to use Java to search an XML file for the word "Smith" and print in the console "Smith, Mike"

<?xml version = "1.0"?>
<class>
   <student rollno = "1">
      <firstname>Doe</firstname>
      <lastname>Jane</lastname>
   </student>
   
   <student rollno = "2">
      <firstname>Smith</firstname>
      <lastname>Mike</lastname>
   </student>
   
   <student rollno = "3">
      <firstname>Fonda</firstname>
      <lastname>Jane</lastname>
   </student>
</class>

I've found resources online to query the whole XML file but had difficulty finding ways to search inside the tags.

try with following solution. in this example used the DOM Parser for parse XML file.

String firstName = "";
Scanner scanner = new Scanner(System.in);

System.out.print("Enter the first name: ");
firstName = scanner.nextLine();
    	
try {
    File inputFile = new File("input.xml");
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document document = builder.parse(inputFile);
    document.getDocumentElement().normalize();
    NodeList nodeList = document.getElementsByTagName("student");
    for (int i = 0; i < nodeList.getLength(); i++) {
        Element element = (Element) nodeList.item(i);
        if(element.getElementsByTagName("firstname").item(0).getTextContent().equals(firstName)){
            System.out.println("Full Name : "+element.getElementsByTagName("firstname").item(0).getTextContent()+" "+
            			   							element.getElementsByTagName("lastname").item(0).getTextContent());
            break;
        }
    }
} catch (Exception e) {
    e.printStackTrace();
}

console output,

Enter the first name: Smith
Full Name : Smith Mike // when enter the first name as "Smith"