Basic Tools

import java.time.format.DateTimeFormatter;  

import java.time.LocalDateTime;    

   DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");  

   LocalDateTime now = LocalDateTime.now();  

   System.out.println(dtf.format(now));  

Dropdown

   import javax.swing.*;

    public class DropDown {

        public static void main(String[] args) {

            String[] optionsToChoose = {"CSA", "CSII", "Accounting", "Adv Accounting", "Business Management", "Entrepreneurship" ,"None of the listed"};

            String getclasses = (String) JOptionPane.showInputDialog(

                    null,

                    "Which class are you working with?",sdfg

                    "Choose Class",

                    JOptionPane.QUESTION_MESSAGE,

                    null,

                    optionsToChoose,

                    optionsToChoose[3]);

            System.out.println("Your chosen class: " + getClasses);

        }

    }

import javax.swing.*;

public class JoptionPaneTest {

   public static void main(String[] args) {

      JFrame frame = new JFrame("JoptionPane Test");

      frame.setSize(200, 200);

      frame.setLocationRelativeTo(null);

      frame.setVisible(true);

      JOptionPane.showMessageDialog(frame, "Hello Java");

      JOptionPane.showMessageDialog(frame, "You have less amount, please recharge","Apocalyptic message", JOptionPane.WARNING_MESSAGE);

      int result = JOptionPane.showConfirmDialog(null, "Do you want to remove item now?");

      switch (result) {

         case JOptionPane.YES_OPTION:

         System.out.println("Yes");

         break;

         case JOptionPane.NO_OPTION:

         System.out.println("No");

         break;

         case JOptionPane.CANCEL_OPTION:

         System.out.println("Cancel");

         break;

         case JOptionPane.CLOSED_OPTION:

         System.out.println("Closed");

         break;

      }

      String name = JOptionPane.showInputDialog(null, "Please enter your name.");

      System.out.println(name);

      JTextField userField = new JTextField();

      JPasswordField passField = new JPasswordField();

      String message = "Please enter your user name and password.";

      result = JOptionPane.showOptionDialog(frame, new Object[] {message, userField, passField},

      "Login", JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE, null, null, null);

      if (result == JOptionPane.OK_OPTION)

      System.out.println(userField.getText() + " " + new String(passField.getPassword()));

      System.exit(0);

   }

}