MySQL & Cyrillic Symbols.

To work with Cyrillic symbols in MySQL:

    sudo gedit /etc/mysql/my.cnf

Add next settings in section [mysqld]:

    default-character-set=utf8
    character-set-server=utf8
    collation-server=utf8_general_ci
    init-connect="SET NAMES utf8"
    skip-character-set-client-handshake

and this to section: [mysqldump]:

    default-character-set=utf8

reboot mysql and enjoy!
Also create table code:

    CREATE TABLE $tablename CHARACTER SET utf8

Java Samples 4. jFrame close confirmation.

...
main.this.addWindowListener(new WindowListener() {
    public void windowClosing(WindowEvent event) {
    Object[] options = { "Yes", "No" };
    int n = JOptionPane.showOptionDialog(event.getWindow(), "Close Window?",
        "Close Window?", JOptionPane.YES_NO_OPTION,
        JOptionPane.QUESTION_MESSAGE, null, options,
 options[0]);
 if (n == 0) event.getWindow().setVisible(false);
    }
    public void windowActivated(WindowEvent event) {}
    public void windowClosed(WindowEvent event) {}
    public void windowDeactivated(WindowEvent event) {}
    public void windowDeiconified(WindowEvent event) {}
    public void windowIconified(WindowEvent event) {}
    public void windowOpened(WindowEvent event) {}
});
initComponents();
...

Also change defaultCloseOperation from EXIT_ON_CLOSE to DO_NOTHING_ON_CLOSE

Java Samples 3. Append Row to jTable

public static void addRow(JTable table, Object[] data) {
    DefaultTableModel tbm = (DefaultTableModel) table.getModel();
    tbm.addRow(data); 
    table.setModel(tbm);
}

Java Samples 2. SQL connections.

public static void voidName(String query) throws SQLException {
    Connection connectionName = DriverManager.getConnection("url" /* хост:порт/база */, "user", "pass");
    if (connectionName==null) { 
        System.exit(0);             
    }
    Statement statementName = connectionName.createStatement(); 
    ResultSet resultsetName = statementName.executeQuery("query"); 
    while(resultsetName.next()) { 
        resultsetName.getString("columnName");
        some_actions_with_columnName
    }
}

Java Samples 1 (String & File)

/* Load file content to string */

public static String fileView(String filename) throws FileNotFoundException, IOException {
   BufferedReader br = new BufferedReader(new FileReader(filename));
   StringBuilder s = new StringBuilder("");
   while (br.ready()) s.append(br.readLine()+"\n");
   return(s.toString());
}

/* Write text to file*/

public static void writeToFile(String fileName, String text) throws IOException {
   try {
      File file = new File(fileName);
      FileWriter fw = new FileWriter(file, true);
      fw.append(text);
      fw.close();
   }
   catch ( IOException ioException ) {
      ioException.printStackTrace();
   }
}

Java Samples 0 (String & ArrayList)

/* delete spaces around the string */

public static String deleteSpaces(String x) {
  if (x.startsWith(" ")) x = x.substring(1);
  if (x.endsWith(" ")) x = x.substring(0, x.length()-1);
  return(x);
}

/* convert ArrayList to String */

public static String listToString(ArrayList list) {
  String s = null;
  if (!list.isEmpty) {
     for (int i = 0; i < list.size(); i++) {
        s.concat(list.get(i).toString()+"\n");
     }
  }
  return(s);
}

/* convert String to ArrayList */

public static ArrayList stringToArrayList(String string) {
   String[] pieces = string.split("\n");
   for (int i=pieces.length-1;i>=0;i--) {
      pieces[i] = pieces[i].trim();
   }
   ArrayList a = new ArrayList(Arrays.asList(pieces));
   return (a);
}