creating a java sub-menu

This java program is used for creating a java sub-menu.

//Java Core Package
import javax.swing.*;
//Java Extension Package
import java.awt.*;

public class creatingSubJMenuItem extends JFrame {

 //Initializing program components
 private JMenu menus;
 private JMenuBar bar;
 private JMenu mainItem[];
 private JMenuItem subItems[];

 //Setting up GUI
    public creatingSubJMenuItem() {
   
     //Setting up the Title of the Window
     super("Creating a Sub JMenuItem");

     //Set Size of the Window (WIDTH, HEIGHT)
     setSize(350,200);

     //Exit Property of the Window
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
  //Constructing JMenu "File" with mnemonic 'F'
     menus = new JMenu("File");
     menus.setMnemonic('F');
   
     //Constructing main JMenu and add it in JMenu "File"
     mainItem = new JMenu[1];
   
     for(int count=0; count<mainItem.length; count++){
      mainItem[count] = new JMenu("Main Menu "+(count+1));
      menus.add(mainItem[count]); //Adding JMenu "mainItem" in the JMenu "File"
     }
   
     //Constructing JMenuItem "subItems" as a Sub Menu to the main JMenu
     subItems = new JMenuItem[5];
   
     for(int count=0; count<subItems.length; count++){
      subItems[count] = new JMenuItem("Sub Menu "+(count+1));
      mainItem[0].add(subItems[count]); //Adding JMenuItem "subItems" in the JMenu "mainItem"
     }
   
     //Constructing JMenuBar
     bar = new JMenuBar();
     bar.add(menus); //Adding the JMenu "File" in the JMenuBar
   
     //Setting up the JMenuBar in the container
     setJMenuBar(bar);

     //Setting up the container ready for the components to be added.
     Container pane = getContentPane();
     setContentPane(pane);

     /**Set all the Components Visible.
      * If it is set to "false", the components in the container will not be visible.
      */
     setVisible(true);
    }
  
 //Main Method
    public static void main (String[] args) {
     creatingSubJMenuItem csjmi = new creatingSubJMenuItem();
 }
}

Password demo in java

package javaapplication1;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Arrays;

public class JavaApplication1 extends JPanel implements ActionListener{

    private static String OK = "ok";
    private static String HELP = "help";

    private JFrame controllingFrame; //needed for dialogs
    private JPasswordField passwordField;

    public JavaApplication1(JFrame f) {
        //Use the default FlowLayout.
        controllingFrame = f;

        //Create everything.
        passwordField = new JPasswordField(10);
        passwordField.setActionCommand(OK);
        passwordField.addActionListener(this);

        JLabel label = new JLabel("Enter the password: ");
        label.setLabelFor(passwordField);

        JComponent buttonPane = createButtonPanel();

        //Lay out everything.
        JPanel textPane = new JPanel(new FlowLayout(FlowLayout.TRAILING));
        textPane.add(label);
        textPane.add(passwordField);

        add(textPane);
        add(buttonPane);
    }

    protected JComponent createButtonPanel() {
        JPanel p = new JPanel(new GridLayout(0,1));
        JButton okButton = new JButton("OK");
        JButton helpButton = new JButton("Help");

        okButton.setActionCommand(OK);
        helpButton.setActionCommand(HELP);
        okButton.addActionListener(this);
        helpButton.addActionListener(this);

        p.add(okButton);
        p.add(helpButton);

        return p;
    }

    public void actionPerformed(ActionEvent e) {
        String cmd = e.getActionCommand();

        if (OK.equals(cmd)) { //Process the password.
            char[] input = passwordField.getPassword();
            if (isPasswordCorrect(input)) {
                JOptionPane.showMessageDialog(controllingFrame,
                    "Success! You typed the right password.");
            } else {
                JOptionPane.showMessageDialog(controllingFrame,
                    "Invalid password. Try again.",
                    "Error Message",
                    JOptionPane.ERROR_MESSAGE);
            }

            //Zero out the possible password, for security.
            Arrays.fill(input, '0');

            passwordField.selectAll();
            resetFocus();
        } else { //The user has asked for help.
            JOptionPane.showMessageDialog(controllingFrame,
                "You can get the password by searching this example's\n"
              + "source code for the string \"correctPassword\".\n"
              + "Or look at the section How to Use Password Fields in\n"
              + "the components section of The Java Tutorial.");
        }
    }

    /**
     * Checks the passed-in array against the correct password.
     * After this method returns, you should invoke eraseArray
     * on the passed-in array.
     */
    private static boolean isPasswordCorrect(char[] input) {
        boolean isCorrect = true;
        char[] correctPassword = { 'b', 'u', 'g', 'a', 'b', 'o', 'o' };

        if (input.length != correctPassword.length) {
            isCorrect = false;
        } else {
            isCorrect = Arrays.equals (input, correctPassword);
        }

        //Zero out the password.
        Arrays.fill(correctPassword,'0');

        return isCorrect;
    }

    //Must be called from the event dispatch thread.
    protected void resetFocus() {
        passwordField.requestFocusInWindow();
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event dispatch thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("PasswordDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        final JavaApplication1 newContentPane = new JavaApplication1(frame);
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Make sure the focus goes to the right component
        //whenever the frame is initially given the focus.
        frame.addWindowListener(new WindowAdapter() {
            public void windowActivated(WindowEvent e) {
                newContentPane.resetFocus();
            }
        });

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                //Turn off metal's use of bold fonts
        UIManager.put("swing.boldMetal", Boolean.FALSE);
        createAndShowGUI();
            }
        });
    }
}

OUT PUT:
TYPE THE PASSWORD AS "bugaboo" AND PRESS OK BUTTON

Textfield demo in java

package javaapplication1;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class JavaApplication1 extends JPanel implements ActionListener{

    protected JTextField textField;
    protected JTextArea textArea;
    private final static String newline = "\n";

    public JavaApplication1() {
        super(new GridBagLayout());

        textField = new JTextField(20);
        textField.addActionListener(this);

        textArea = new JTextArea(5, 20);
        textArea.setEditable(false);
        JScrollPane scrollPane = new JScrollPane(textArea);

        //Add Components to this panel.
        GridBagConstraints c = new GridBagConstraints();
        c.gridwidth = GridBagConstraints.REMAINDER;

        c.fill = GridBagConstraints.HORIZONTAL;
        add(textField, c);

        c.fill = GridBagConstraints.BOTH;
        c.weightx = 1.0;
        c.weighty = 1.0;
        add(scrollPane, c);
    }

    public void actionPerformed(ActionEvent evt) {
        String text = textField.getText();
        textArea.append(text + newline);
        textField.selectAll();

        //Make sure the new text is visible, even if there
        //was a selection in the text area.
        textArea.setCaretPosition(textArea.getDocument().getLength());
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event dispatch thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("TextDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Add contents to the window.
        frame.add(new JavaApplication1());

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
    }