JDOMを使用してxmlファイルを解析する

public class JDomReader {
	
	public static void main(String[] args) {
		
		SAXBuilder builder = new SAXBuilder();
		
		try {
			Document doc = builder.build(new File("test.xml"));
			
			Element root = doc.getRootElement();
			System.out.println(root.getName());
			
			Element student = root.getChild("student");
			
			String id = student.getAttribute("id").getValue();
			System.out.println("id = " + id);

			student.removeChild("username");
			
//			List list = doc.getContent();
//			System.out.println(list.size());
			
			XMLOutputter out = new XMLOutputter(Format.getPrettyFormat().setIndent("    "));
			out.output(doc, new FileWriter("result.xml"));
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<root>
    <student id="1">
        <username>  </username>
    </student>
    <student id="2">
        <username>  </username>
    </student>
</root>