title: Java Login 3 times Attempt Message box appears continuously
body: <p>I am creating a login attempt that will block the user or exit the system if he put or typed a wrong user password.</p>
  
  <p>Please help me why my message box keeps looping continuously?   </p>
  
  <pre><code>private void login() {
  
      String stru = "";
      stru = TxtUserName.getText();
  
      String strp = "";
      strp = TxtPassword.getText();
      if (stru.isEmpty() == true) {
          JOptionPane.showMessageDialog(null, "Enter User Name");
          return;
      }
  
      if (strp.isEmpty() == true) {
          JOptionPane.showMessageDialog(null, "Enter Password");
          return;
      }
  
      try {
  
          //get database connection details
          Connect mc = new Connect();
  
          //open connection
          Connection connection;
          connection = DriverManager.getConnection(mc.StrUrl, mc.StrUid, mc.StrPwd);
          String str = "";
          str = "select * from lib_user where user_name =? and user_password =?";
          PreparedStatement pst = connection.prepareStatement(str);
          pst.setString(1, stru);
          pst.setString(2, strp);
          ResultSet rs;
          rs = pst.executeQuery();
          int i = 0;
          do {
              if (rs.next()) {
                  Connect.StrUser = TxtUserName.getText();
                  MainForm m = new MainForm();
  
                  this.setVisible(false);
                  JOptionPane.showMessageDialog(null, "Welcome to BIR Library Management System", "Welcome", JOptionPane.INFORMATION_MESSAGE);
                  m.setVisible(true);
              } else {
                  i++;
  //            TxtPassword.disable();
                  //            TxtUserName.disable();
  
                  JOptionPane.showMessageDialog(null, "User name or password are not correct." + i);
  
                  //            return;
              }
  
          } while (i &lt; 3);
  
          System.out.println("You screwed up.");
  
      } catch (Exception e) {
  
          {
              JOptionPane.showMessageDialog(null, e, "Error", JOptionPane.ERROR_MESSAGE);
          }
          //            System.exit(1);
      }
  }
  </code></pre>