Thêm vào file XML

    private void btNhapActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
        if (txtFile.getText().isEmpty()) {
            JOptionPane.showMessageDialog(null, "Error!");
        } else {
            try {
                // Lay ma Hash
                strMD5 = ToMD5(file.getAbsolutePath());
                strSHA1 = ToSHA1(file.getAbsolutePath());
                strSHA256 = ToSHA256(file.getAbsolutePath());
                strSHA384 = ToSHA384(file.getAbsolutePath());
                strSHA512 = ToSHA512(file.getAbsolutePath());

                // Doc file
                SAXBuilder builder = new SAXBuilder();
                File xmlFile = new File("MalwareData.xml");
                Document doc = (Document) builder.build(xmlFile);
                Element rootNode = doc.getRootElement();

                // update them file
                Element objects = rootNode.getChild("objects");
                List<Element> test = objects.getChildren();
                //System.out.println(test.size() + 1);
                String IDnext = String.valueOf(test.size() + 1);
                Element eFile = new Element("file").setAttribute("ID", IDnext);
                eFile.addContent(new Element("md5").setText(strMD5));
                eFile.addContent(new Element("sha1").setText(strSHA1));
                eFile.addContent(new Element("sha256").setText(strSHA256));
                eFile.addContent(new Element("sha384").setText(strSHA384));
                eFile.addContent(new Element("sha512").setText(strSHA512));
                eFile.addContent(new Element("filename").setText(file.getName()));
                eFile.addContent(new Element("size").setText(String.valueOf(file.length()) + " byte"));
                int dot = file.getName().lastIndexOf(".");
                String strType = "NULL";
                if (dot >= 0) {
                    strType = file.getName().substring(dot + 1).toUpperCase();
                }
                eFile.addContent(new Element("MINEType").setText(strType));
                String strMalwareName = txtSign.getText();
                if (txtSign.getText().isEmpty()) {
                    strMalwareName = "NULL";
                }
                eFile.addContent(new Element("MalwareName").setText(strMalwareName));
                String strSign = txtSign.getText();
                if (txtSign.getText().isEmpty()) {
                    strSign = "NULL";
                }
                eFile.addContent(new Element("Sign").setText(strSign));

                objects.addContent(eFile);


                // cap nhat thoi gian
                DateFormat dateFormat = new SimpleDateFormat("HH:mm:ss dd/MM/yyyy");
                String timeCurrent = dateFormat.format(new Date());
                Element timestamp = rootNode.getChild("timestamp");
                timestamp.setText(timeCurrent);

                // ghi file
                XMLOutputter xmlOutput = new XMLOutputter();
                xmlOutput.setFormat(Format.getPrettyFormat());
                xmlOutput.output(doc, new FileWriter("MalwareData.xml"));
                // Thong bao thanh cong
                System.out.println("File updated!");
                JOptionPane.showMessageDialog(null, "File updated!");
            } catch (Exception ex) {
            }
        }
    }