DatePicker.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
//create class
class DatePicker 
{
	//define variables
        int month = java.util.Calendar.getInstance().get(java.util.Calendar.MONTH);
        int year = java.util.Calendar.getInstance().get(java.util.Calendar.YEAR);
        //create object of JLabel with alignment
        JLabel l = new JLabel("", JLabel.CENTER);
        //define variable
        String day = "";
        //declaration
        JDialog d;
        //create object of JButton
        JButton[] button = new JButton[49];
 
        public DatePicker(JFrame parent)//create constructor 
        {
        	//create object
                d = new JDialog();
                //set modal true
                d.setModal(true);
                //define string
                String[] header = { "Sun", "Mon", "Tue", "Wed", "Thur", "Fri", "Sat" };
                //create JPanel object and set layout
                JPanel p1 = new JPanel(new GridLayout(7, 7));
                //set size
                p1.setPreferredSize(new Dimension(430, 120));
                //for loop condition
                for (int x = 0; x < button.length; x++) 
                {		
                	//define variable
                        final int selection = x;
                        //create object of JButton
                        button[x] = new JButton();
                        //set focus painted false
                        button[x].setFocusPainted(false);
                        //set background colour
                        button[x].setBackground(Color.white);
                        //if loop condition
                        if (x > 6)
                        //add action listener
                        button[x].addActionListener(new ActionListener() 
                        {
                                 public void actionPerformed(ActionEvent ae) 
                                 {
                                       day = button[selection].getActionCommand();
                                       //call dispose() method
                                       d.dispose();
                                 }
                        });
                        if (x < 7)//if loop condition 
                        {
                                button[x].setText(header[x]);
                                //set fore ground colour
                                button[x].setForeground(Color.red);
                        }
                        p1.add(button[x]);//add button
                }
                //create JPanel object with grid layout
                JPanel p2 = new JPanel(new GridLayout(1, 3));
                
                //create object of button for previous month
                JButton previous = new JButton("<< Previous");
                //add action command
                previous.addActionListener(new ActionListener() 
                {
                        public void actionPerformed(ActionEvent ae) 
                        {
                            //decrement month by 1
                            month--;
                            //call method
                            displayDate();
                        }
                });
                p2.add(previous);//add button
                p2.add(l);//add label
                //create object of button for next month
                JButton next = new JButton("Next >>");
                //add action command
                next.addActionListener(new ActionListener()
                {
                        public void actionPerformed(ActionEvent ae) 
                        {
                             //increment month by 1
                             month++;
                             //call method
                            displayDate();
                        }
                });
                p2.add(next);// add next button
                //set border alignment
                d.add(p1, BorderLayout.CENTER);
                d.add(p2, BorderLayout.SOUTH);
                d.pack();
                //set location
                d.setLocationRelativeTo(parent);
                //call method
                displayDate();
                //set visible true
                d.setVisible(true);
        }
 
        public void displayDate() 
        {
        	for (int x = 7; x < button.length; x++)//for loop
        	button[x].setText("");//set text
      	        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd");	
                //create object of SimpleDateFormat 
                java.util.Calendar cal = java.util.Calendar.getInstance();			
                //create object of java.util.Calendar 
        	cal.set(year, month, 1); //set year, month and date
         	//define variables
        	int dayOfWeek = cal.get(java.util.Calendar.DAY_OF_WEEK);
        	int daysInMonth = cal.getActualMaximum(java.util.Calendar.DAY_OF_MONTH);
        	//condition
        	for (int x = 6 + dayOfWeek, day = 1; day <= daysInMonth; x++, day++)
        	//set text
        	button[x].setText("" + day);
        	l.setText(sdf.format(cal.getTime()));
        	//set title
        	d.setTitle("Date Picker");
        }
 
        public String setPickedDate() 
        {
        	//if condition
        	if (day.equals(""))
        		return day;
            java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("dd-MM-yyyy");
            java.util.Calendar cal = java.util.Calendar.getInstance();
            cal.set(year, month, Integer.parseInt(day));
            return sdf.format(cal.getTime());
        }
}
 
class Picker 
{
        public static void main(String[] args) // main method
        {
        	//create object of JLabel and set label
        	JLabel label = new JLabel("Selected Date:");
        	//create object of JTextField and declare it final
        	final JTextField text = new JTextField(20);
        	//create object of JButton
        	JButton b = new JButton("popup");
        	//create object of JPanel
        	JPanel p = new JPanel();
        	p.add(label);
        	p.add(text);
        	p.add(b);
        	//create object of JFrame and declare it final
        	final JFrame f = new JFrame();
        	f.getContentPane().add(p);
        	f.pack();
        	f.setVisible(true);
        	//add action listener
        	b.addActionListener(new ActionListener() 
        	{
        		public void actionPerformed(ActionEvent ae) 
        		{
        			//set text i.e. date
        			text.setText(new DatePicker(f).setPickedDate());
        		}
            });
        }
}