title: Alert window until method finishes execution in Swing
body: <p>The shown image is my window made using <code>Swing</code>. </p>
  
  <p>How do I create an alert window when i click <code>Submit</code> button  and the alert should display until the action performed is completed(alert+code should run in background) ?</p>
  
  <p>Here is my code snippet :</p>
  
  <pre><code>private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
      //alert window should start here when button performed
      //and end based on the output i get
      DefaultHttpClient httpclient  = new DefaultHttpClient();
      jLabel3.setText("");
      try {
          httpclient.getCredentialsProvider().setCredentials(
              new AuthScope(getHost(), AuthScope.ANY_PORT),
              new UsernamePasswordCredentials(getUser(), getPass()));                    
          HttpResponse response = null;
          HttpEntity entity = null;
          try {
              response = httpclient.execute(httpget);
              if(response.getStatusLine().getStatusCode()==500) {
                  jLabel3.setText("Such Goods Movement does not exist / You do not have permssions for the entered.");
                  //end here or 
              } else if(response.getStatusLine().getStatusCode()==401) {
                  System.out.println(response);
                  jLabel3.setText("Auth Failed");
                  //end here or soon based on the event
              }
              entity = response.getEntity();
              System.out.println(entity);
              if (entity != null) {
                  InputStream instream = entity.getContent();
                  System.out.println(instream);
                  BufferedReader reader = new BufferedReader(
                      new InputStreamReader(instream));
                  String inputLine;
                  String xmlText="";
                  while ((inputLine = reader.readLine()) != null)
                      xmlText = xmlText+inputLine+"\n";
                  System.out.println(xmlText);
                  try {
                      DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
                      InputSource is = new InputSource();
                      is.setCharacterStream(new StringReader(xmlText));
                      DefaultTableModel model = (DefaultTableModel) jTable1.getModel();
                      model.setRowCount(0);
                      Document doc = db.parse(is);
                      NodeList nodes = doc.getElementsByTagName("MaterialMgmtInternalMovementLine");
                      for (int i = 0; i &lt; nodes.getLength(); i++) {
                          Element element = (Element) nodes.item(i);
                          getListGRNLine(element);
                      }
                  } catch (SAXException ex) {
                      Logger.getLogger(GoodsReceipt.class.getName()).log(Level.SEVERE, null, ex);
                  } catch (ParserConfigurationException ex) {
                      Logger.getLogger(GoodsReceipt.class.getName()).log(Level.SEVERE, null, ex);
                  }
              }
          } catch(UnknownHostException e){
              jLabel3.setText("URL Not Found / Check Internet Connectivity");
          } catch(NoRouteToHostException f){
              jLabel3.setText("URL Not Found / Check Internet Connectivity");
          } catch (IOException ex) {
              Logger.getLogger(GoodsReceipt.class.getName()).log(Level.SEVERE, null, ex);
          }
          try {
              EntityUtils.consume(entity);
          } catch (IOException ex) {
              Logger.getLogger(GoodsReceipt.class.getName()).log(Level.SEVERE, null, ex);
          }
      } catch (UnsupportedEncodingException ex) {
          Logger.getLogger(GoodsReceipt.class.getName()).log(Level.SEVERE, null, ex);
      } finally {
          // When HttpClient instance is no longer needed,
          // shut down the connection manager to ensure
          // immediate deallocation of all system resources
          httpclient.getConnectionManager().shutdown();
      }
  }
  </code></pre>
  
  <p>Image Window : </p>
  
  <p><img src="https://i.stack.imgur.com/qckJV.png" alt="IMAGEWINDOW"></p>