import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GraphicsConfiguration;
import java.awt.GridLayout;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.TreeMap;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Project4 extends JFrame implements ActionListener {
// defines the database of property records
// with the transaction number field as the key and
//a Property object as the value
private TreeMap<Integer,Property> database ;
private final String[] processItems = {"Insert","Delete","Find"}
                  , statusItems = {"FOR_SALE" ,
                     "UNDER_CONTRACT" , "SOLD"};
private Color backGroundColor ;
private Font font;
private JPanel mainPane ;
private JLabel transactionJLabel, addressJLabel, bedRoomsJLabel
         , squareFootageJLabel , priceJLabel;
private JTextField transactionJTextField, addressJTextField,
         bedRoomsJTextField , squareFootageJTextField
         , priceJTextField;
private JComboBox processJComboBox , statusJComboBox;
private JButton processJButton , changeStatusJButton;
//////////////////
public Project4(){
   database = new TreeMap<Integer,Property>();
   database.clear();
   backGroundColor = new Color(240,240,240);
   font = new Font("Times New Roman", 0, 25);
   setWindowProperites();
}

/**
* this function set Window Properites
*/
private void setWindowProperites(){
   this.setFont(font);
   this.setTitle("Real Estate Database");
   this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   this.setBackground(backGroundColor);
   this.setSize(new Dimension(610, 450));
   this.setPreferredSize(new Dimension(610, 450));
   this.setResizable(false);
   this.setLocationRelativeTo(null);
   createMainPanel();
   this.setLayout(null);
   this.add(mainPane);
   this.setVisible(true);

}

/**
* this function create Main Panel for JFrame (Window)
*/
private void createMainPanel(){
   this.mainPane = new JPanel();
   this.mainPane.setSize(600,400);
   this.mainPane.setPreferredSize(new Dimension(600, 400));
   this.mainPane.setLocation(0,0);
   createJLabelComponents();
   createJComboBoxComponents();
   createJTextFieldComponents();
   createJButtonComponents();
   this.mainPane.setLayout(new GridLayout(0,2,30,30));
   this. mainPane.add(this.transactionJLabel);
   this.mainPane.add(this.transactionJTextField);
   this. mainPane.add(this.addressJLabel);
   this. mainPane.add(this.addressJTextField);
   this. mainPane.add(this.bedRoomsJLabel);
   this. mainPane.add(this.bedRoomsJTextField);
   this. mainPane.add(this.squareFootageJLabel);
   this. mainPane.add(this.squareFootageJTextField);
   this. mainPane.add(this.priceJLabel);
   this. mainPane.add(this.priceJTextField);
   this. mainPane.add(this.processJButton);
   this. mainPane.add(this.processJComboBox);
   this. mainPane.add(this.changeStatusJButton);
   this. mainPane.add(this.statusJComboBox);
}

/**
* this function create JLabel Components
*/
private void createJLabelComponents(){
   this.transactionJLabel = new JLabel();
   this.transactionJLabel.setFont(font);
   this.transactionJLabel.setText("Transaction No:");
   //////////////////////////
   this.addressJLabel = new JLabel();
   this.addressJLabel.setFont(font);
   this.addressJLabel.setText("Address:");
   //////////////////////////
   this.bedRoomsJLabel = new JLabel();
   this.bedRoomsJLabel.setFont(font);
   this.bedRoomsJLabel.setText("BedRooms:");
   //////////////////////////
   this.squareFootageJLabel = new JLabel();
   this.squareFootageJLabel.setFont(font);
   this.squareFootageJLabel.setText("Square Footage:");
   //////////////////////////
   this.priceJLabel = new JLabel();
   this.priceJLabel.setFont(font);
   this.priceJLabel.setText("Price:");

}

/**
* this function create JComboBox Components
*/
private void createJComboBoxComponents(){
   processJComboBox = new JComboBox<>(processItems);
   processJComboBox.setFont(font);
   processJComboBox.setSelectedIndex(0);
   processJComboBox.setActionCommand("process");
   processJComboBox.addActionListener(this);
   ///////////////////////////////////////////
   statusJComboBox = new JComboBox<>(statusItems);
   statusJComboBox.setFont(font);
   statusJComboBox.setSelectedIndex(0);
   statusJComboBox.setActionCommand("status");
   statusJComboBox.addActionListener(this);

}

Step 1 Develop the following class: Class Name: Instrument Acce...