import java.io.File;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.CDATASection;
import org.w3c.dom.CharacterData;
import org.w3c.dom.Comment;
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.getElementById("key1");
CDATASection cdataNode = doc.createCDATASection("");
Comment commentNode = doc.createComment("");
Text textNode = doc.createTextNode("");
// All three types of nodes implement the CharacterData interface
CharacterData cdata = cdataNode;
cdata = commentNode;
cdata = textNode;
// Replace text
String replacement = "c";
int offset = 10;
int len = 6;
cdata.replaceData(offset, len, replacement);
}
}