import java.io.File;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;
public class Main {
public static void main(String[] argv) throws Exception {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating(true);
factory.setExpandEntityReferences(false);
Document doc = factory.newDocumentBuilder().parse(new File("filename"));
Element element = doc.getDocumentElement();
Text text1 = (Text) element.getFirstChild();
String string = text1.getData();
String word = "some";
Text text2 = text1.splitText(string.indexOf(word));
Element newElement = doc.createElement("b");
newElement.appendChild(text2);
element.insertBefore(newElement, text2);
}
}