public class ConnectionMysql {
    public static void main(String[] args) throws ClassNotFoundException, SQLException, UnsupportedEncodingException {
      Class.forName("com.mysql.jdbc.Driver");
        Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb?useUnicode=yes&characterEncoding=UTF-8&user=root&password=root");
        PreparedStatement stmt = null; 
         stmt = con.prepareStatement("set names utf8");
        stmt.execute();
        stmt = con.prepareStatement("set character set utf8");
        stmt.execute();

        
           stmt = con.prepareStatement("INSERT INTO MESSAGE (message_text, user_id) VALUES (? ,?)");
          String  msg= "русские буквы  df df";
//1
            stmt.setString(1,msg );
//2
            stmt.setInt(2,33);
            stmt.execute();

    }
    
}