title: Check if a Integer is empty
body: <p>I want to check if a <code>Integer</code> value is empty.
  The value for <code>Integer</code> is completed in a form. Here is my code.</p>
  
  <p>Here the value is introduced:</p>
  
  <pre><code>&lt;input name="varsta" placeHolder="Varsta:" type="text" data-constraints='@NotEmpty @Required @AlphaSpecial'&gt; &lt;br/&gt;&lt;br/&gt;
  </code></pre>
  
  <p>Now I want to check if there are data introduced or not.</p>
  
  <pre><code>protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  
      response.setContentType("text/html;charset=UTF-8");
      PrintWriter out = response.getWriter();
  
      Integer varsta = Integer.parseInt(request.getParameter("varsta"));
      request.getSession().setAttribute("varsta", varsta);
  
      try {
          DBConnection connection = new DBConnection();
          Connection con = connection.Connect();
  
          PreparedStatement ps = con.prepareStatement(
              "insert into user(Nume,Prenume,E_mail,Parola,Varsta,Sex,Greutate,Inaltime,Nivel_activitate,Calcul_calorii)" + 
              "values ('"+nume+"','"+prenume+"','"+email1+"','"+parola+"','"+varsta+"','"+sex+"','"+greutate+"','"+inaltime+"','"+activitate+"','"+calorii+"')"
          );
  
          if (varsta == null &amp;&amp; "".equals(varsta)) {
              String message = "Va rugam completati cu atentie TOATE campurile!";
              request.setAttribute("message", message);
              request.getRequestDispatcher("/inregistrare.jsp").forward(request, response);           
          } else {
             int i = ps.executeUpdate();
  
             if (i &gt; 0) {
                request.getRequestDispatcher("/preferinte.jsp").forward(request, response);
             }
          }
          ps.close();
          con.close();         
      } catch(Exception se) {
          se.printStackTrace();
      }
  }       
  </code></pre>
  
  <p>is not working.</p>
  
  <p>Could anyone help me?</p>