✅ UNIT 1: INTRODUCTION TO OOP AND JAVA FUNDAMENTALS

Contact Hours: 8

1. Case Study 1:
   A start-up is developing a student management system in Java. How will you utilize Object-Oriented Programming principles such as encapsulation, abstraction, inheritance, and polymorphism to design its architecture? Illustrate with class diagrams and code snippets.

2. Case Study 2:
   You are asked to build a calculator application that supports basic arithmetic operations using Java. Describe how you would structure the Java source file, manage compilation, and implement methods, static members, and control flow statements efficiently.

3. Case Study 3:
   A university wants to generate reports for thousands of students. Explain how arrays and packages can be used to modularize the program. Also discuss how JavaDoc comments would be useful for long-term code maintenance.

4. Case Study 4:
   Assume a situation where a sensor data monitoring application needs to be developed. How would you define appropriate data types, variables, and use access specifiers to ensure secure and optimized coding practices?

5. Case Study 5:
   An educational platform wants to simulate the concept of classes and objects for teaching. Design a class-based Java program to represent books in a library, including methods like borrow(), return(), and displayDetails(). Highlight how this showcases OOP fundamentals.

✅ UNIT 2: INHERITANCE AND INTERFACES

Contact Hours: 8

1. Case Study 1:
   Design an application for a vehicle rental system using inheritance. Define a superclass Vehicle and derive classes like Car, Bike, and Truck. Discuss how constructors in subclasses and protected members are useful.

2. Case Study 2:
   Develop a Java program using interfaces to model different payment methods like UPI, CreditCard, and NetBanking. Justify why interfaces are more appropriate than abstract classes in this case.

3. Case Study 3:
   A software firm uses a class Person to represent both employees and customers. How would you use the Object class, method overriding, and final keywords to prevent modification in some parts of the class hierarchy?

4. Case Study 4:
   Discuss a situation where object cloning is essential, such as copying user profiles. Explain how to implement cloning in Java and the role of the Cloneable interface.

5. Case Study 5:
   Create a case where inner classes and collections like Array, List, and String are used to manage product inventory in an e-commerce application. How does the inner class help in encapsulating helper logic?

✅ UNIT 3: EXCEPTION HANDLING AND I/O

Contact Hours: 8

1. Case Study 1:
   While developing a file processing system, you encounter frequent errors such as FileNotFound and IOException. Discuss how built-in exceptions and custom exceptions can be used to manage such scenarios.

2. Case Study 2:
   Design an online form submission system that logs exceptions in a file. Explain how you will use exception hierarchy, stack trace elements, and file I/O concepts to log the details efficiently.

3. Case Study 3:
   Explain a scenario where a program processes sensor data using character streams and displays them on the console. How would you use byte vs character streams to optimize for speed and compatibility?

4. Case Study 4:
   You are building a command-line tool in Java for file conversion. How do you handle reading and writing files and manage I/O exceptions simultaneously?

5. Case Study 5:
   Create a console-based grade report system. Use Java’s I/O streams to read marks from a file and write the final grade to another file. Highlight exception safety and file handling techniques.

✅ UNIT 4: MULTITHREADING AND GENERIC PROGRAMMING

Contact Hours: 8

1. Case Study 1:
   A weather application requires continuous updates without interrupting the user interface. How would you implement multithreading, define the thread life cycle, and synchronize threads in this use case?

2. Case Study 2:
   Design a system that downloads files from the internet and scans them for viruses simultaneously. Discuss how you would use inter-thread communication and daemon threads.

3. Case Study 3:
   Develop a thread group-based system to simulate multiple sensor inputs in a smart city application. Justify the use of thread groups for scalability and resource management.

4. Case Study 4:
   Suppose you are developing a type-safe collection system using generics. Create a case where generic methods and classes handle different types of user data while ensuring type safety.

5. Case Study 5:
   A project aims to sort and filter data across various types. Explain how bounded type parameters and the limitations of generics influence the system’s design.

✅ UNIT 5: EVENT DRIVEN PROGRAMMING

Contact Hours: 8

1. Case Study 1:
   Develop a GUI-based quiz application using Java Swing. Explain the use of frames, buttons, checkboxes, and event handlers to handle user interaction.

2. Case Study 2:
   Create a drawing tool using Java that allows users to draw 2D shapes, choose colors, and modify fonts. Discuss how you would manage these using graphics programming and AWT components.

3. Case Study 3:
   In a retail billing system, users should be able to select items from a list, view the total amount, and check out. Explain the use of scrollbars, lists, and radio buttons in developing this system.

4. Case Study 4:
   Design a file explorer window using Java Swing that supports menus, dialog boxes, and action events. Discuss layout managers used and adapter classes applied in this system.

5. Case Study 5:
   Explain a case where mouse events and key actions are used to build a desktop-based game application. How does the AWT event hierarchy play a role in responsive design?

In Java Swing, user interface (UI) applications are typically structured around windows and containers, wherein user interactions are facilitated through components such as menus and dialog boxes. These elements collectively support the creation of intuitive, interactive, and structured GUI applications. Swing provides comprehensive support for these constructs using classes from the javax.swing package.

1. Windows in Swing

Windows are the primary top-level containers that serve as the foundation for Java GUI applications. In Swing, the most commonly used window containers include JFrame, JDialog, and JWindow.

JFrame

• JFrame is the most commonly used container in Swing, which represents a top-level window with a title bar, border, and buttons for closing, minimizing, and maximizing.
• It supports adding components such as panels, labels, buttons, and menus.

Example:

JFrame frame = new JFrame("My Window");

frame.setSize(400, 300);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setVisible(true);

JWindow

• JWindow is a top-level container without a title bar or border.
• It is useful for splash screens or utility pop-ups.

JDialog

• JDialog is a pop-up window typically used for interaction with the user (e.g., confirmation messages).
• It can be modal or non-modal.

2. Menus in Swing

Menus provide a hierarchical structure for organizing commands and actions that users can perform within the application. Swing supports menu implementation using the following components:

JMenuBar

• This component is used to create a menu bar, which usually appears at the top of the window.
• It can contain multiple JMenu items.

JMenu

• Represents an individual menu that can hold multiple JMenuItem objects.
• A menu can also contain submenus and separators for better organization.

JMenuItem

• Represents a clickable item within a JMenu. It can trigger actions via listeners such as ActionListener.

Example:

JMenuBar menuBar = new JMenuBar();

JMenu fileMenu = new JMenu("File");

JMenuItem openItem = new JMenuItem("Open");

fileMenu.add(openItem);

menuBar.add(fileMenu);

frame.setJMenuBar(menuBar);

Advanced Menu Options:

• JCheckBoxMenuItem: Menu items with a checkbox.
• JRadioButtonMenuItem: Radio button menu items for exclusive selections.
• Mnemonics and Accelerators: Keyboard shortcuts can be assigned to menus using methods like setMnemonic() and setAccelerator().

3. Dialog Boxes in Swing

Dialog boxes are pop-up windows used to convey messages or capture user input. Swing provides a wide range of dialog components through both predefined classes and custom implementations.

Types of Dialogs

a. Message Dialog (showMessageDialog)

• Displays a simple message to the user.

JOptionPane.showMessageDialog(frame, "Operation Completed Successfully");

b. Confirm Dialog (showConfirmDialog)

• Presents Yes/No/Cancel options to the user and returns an integer based on the selection.

int response = JOptionPane.showConfirmDialog(frame, "Are you sure?");

c. Input Dialog (showInputDialog)

• Prompts the user to input a value.

String name = JOptionPane.showInputDialog(frame, "Enter your name:");

d. Option Dialog (showOptionDialog)

• A flexible dialog allowing a combination of custom buttons, icons, and messages.

Custom Dialogs

• Custom dialogs can be created using the JDialog class when predefined methods are insufficient.
• Developers can control modality, layout, and interaction logic.

Example:

JDialog dialog = new JDialog(frame, "Custom Dialog", true);

dialog.setSize(300, 150);

dialog.setLayout(new FlowLayout());

dialog.add(new JLabel("This is a custom dialog box"));

dialog.setVisible(true);

Key Characteristics and Best Practices

Program:

import javax.swing.*;

import java.awt.event.*;

public class SwingWindowMenuDialogDemo {

    public static void main(String[] args) {

        // Create the main JFrame (window)

        JFrame frame = new JFrame("Swing Window with Menu and Dialog");

        frame.setSize(400, 300);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Create a JMenuBar

        JMenuBar menuBar = new JMenuBar();

        // Create a JMenu

        JMenu fileMenu = new JMenu("File");

        JMenu helpMenu = new JMenu("Help");

        // Create JMenuItems

        JMenuItem openItem = new JMenuItem("Open");

        JMenuItem exitItem = new JMenuItem("Exit");

        JMenuItem aboutItem = new JMenuItem("About");

        // Add items to the "File" menu

        fileMenu.add(openItem);

        fileMenu.addSeparator();  // Adds a separator line

        fileMenu.add(exitItem);

        // Add items to the "Help" menu

        helpMenu.add(aboutItem);

        // Add menus to the menu bar

        menuBar.add(fileMenu);

        menuBar.add(helpMenu);

        // Set the menu bar on the frame

        frame.setJMenuBar(menuBar);

        // ActionListener for "Open"

        openItem.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                JOptionPane.showMessageDialog(frame, "Open menu clicked", "Message", JOptionPane.INFORMATION_MESSAGE);

            }

        });

        // ActionListener for "Exit"

        exitItem.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                int confirm = JOptionPane.showConfirmDialog(frame, "Are you sure you want to exit?", "Confirm Exit", JOptionPane.YES_NO_OPTION);

                if (confirm == JOptionPane.YES_OPTION) {

                    System.exit(0);

                }

            }

        });

        // ActionListener for "About"

        aboutItem.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                JOptionPane.showMessageDialog(frame, "Java Swing GUI Demo\nCreated by Krishna", "About", JOptionPane.INFORMATION_MESSAGE);

            }

        });

        // Make the frame visible

        frame.setVisible(true);

    }

}

output:

Conclusion

The capability to integrate windows, menus, and dialog boxes seamlessly is one of the defining strengths of Java Swing. These components provide developers with a high degree of control over both the functionality and user experience of their applications. Through features like keyboard accelerators, modal dialogs, and dynamic menu generation, Swing empowers the development of modern, accessible, and responsive desktop applications. Mastery of these components is essential for developing professional-grade Java interfaces.

Swing Components: An Overview

Java Swing provides a comprehensive suite of user interface components that are used to build feature-rich desktop applications. These components are a part of the javax.swing package and are more flexible, platform-independent, and lightweight in comparison to their AWT counterparts. Each Swing component is designed with a high degree of modularity and is capable of supporting advanced event handling, rendering customizations, and accessibility features.

Swing components inherit from the root class javax.swing.JComponent, which provides fundamental properties such as borders, tooltips, double-buffering, and key/mouse event handling. The key advantage of Swing components is their ability to be integrated seamlessly with various layout managers and their adherence to the Model-View-Controller (MVC) architecture.

Below are detailed descriptions of commonly used Swing components:

1. JTextField (Text Field)

A JTextField is a single-line text component used to input or display a line of editable text.

• Class: javax.swing.JTextField
• Key Methods:
• getText() – Retrieves the current text.
• setText(String text) – Sets the displayed text.
• setColumns(int) – Sets the width of the text field in terms of character columns.

Example:

JTextField textField = new JTextField(20);

panel.add(textField);

2. JTextArea (Text Area)

The JTextArea component allows the user to enter multiple lines of text. It is often used for larger input fields such as comments, logs, or messages.

• Class: javax.swing.JTextArea
• Key Features:
• Supports line wrapping and scrolling (when used with JScrollPane).
• Can be editable or read-only.
• Key Methods:
• append(String) – Appends text to the area.
• setLineWrap(boolean) – Enables line wrap.
• setWrapStyleWord(boolean) – Wraps at word boundaries.

Example:

JTextArea textArea = new JTextArea(5, 20);

textArea.setLineWrap(true);

JScrollPane scrollPane = new JScrollPane(textArea);

panel.add(scrollPane);

3. JButton (Button)

A JButton is a push button that triggers an action when clicked. It can display text, images, or both.

• Class: javax.swing.JButton
• Usage: Commonly used to submit data, trigger functions, or navigate interfaces.
• Event Handling: Listeners such as ActionListener are attached to capture click events.

Example:

JButton button = new JButton("Submit");

button.addActionListener(e -> System.out.println("Button clicked"));

panel.add(button);

4. JCheckBox (Check Box)

The JCheckBox is used to create checkboxes that allow users to select or deselect options independently.

• Class: javax.swing.JCheckBox
• Key Methods:
• isSelected() – Returns true if the box is checked.
• setSelected(boolean) – Sets the checkbox state.

Example:

JCheckBox checkBox = new JCheckBox("Accept Terms");

panel.add(checkBox);

5. JRadioButton (Radio Button)

The JRadioButton is used to create mutually exclusive options where only one selection is allowed among a group.

• Class: javax.swing.JRadioButton
• Grouping: To make a group of radio buttons mutually exclusive, they must be added to a ButtonGroup.

Example:

JRadioButton male = new JRadioButton("Male");

JRadioButton female = new JRadioButton("Female");

ButtonGroup group = new ButtonGroup();

group.add(male);

group.add(female);

panel.add(male);

panel.add(female);

Key Characteristics of Swing Components

Program:

import javax.swing.*;

import java.awt.*;

import java.awt.event.*;

public class SwingComponentDemo {

    public static void main(String[] args) {

        // Create JFrame

        JFrame frame = new JFrame("Swing Components Demo");

        frame.setSize(500, 400);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setLayout(new FlowLayout());

        // JLabel and JTextField

        JLabel nameLabel = new JLabel("Enter Name:");

        JTextField nameField = new JTextField(20);

        // JLabel and JTextArea

        JLabel addressLabel = new JLabel("Enter Address:");

        JTextArea addressArea = new JTextArea(4, 20);

        addressArea.setLineWrap(true);

        addressArea.setWrapStyleWord(true);

        JScrollPane scrollPane = new JScrollPane(addressArea);

        // JCheckBoxes

        JLabel languageLabel = new JLabel("Select Languages Known:");

        JCheckBox cb1 = new JCheckBox("Java");

        JCheckBox cb2 = new JCheckBox("Python");

        JCheckBox cb3 = new JCheckBox("C++");

        // JRadioButtons (Gender Selection)

        JLabel genderLabel = new JLabel("Select Gender:");

        JRadioButton male = new JRadioButton("Male");

        JRadioButton female = new JRadioButton("Female");

        ButtonGroup genderGroup = new ButtonGroup(); // Grouping the radio buttons

        genderGroup.add(male);

        genderGroup.add(female);

        // JButton

        JButton submitButton = new JButton("Submit");

        // ActionListener for button

        submitButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                String name = nameField.getText();

                String address = addressArea.getText();

                String languages = "";

                if (cb1.isSelected()) languages += "Java ";

                if (cb2.isSelected()) languages += "Python ";

                if (cb3.isSelected()) languages += "C++ ";

                String gender = "";

                if (male.isSelected()) gender = "Male";

                else if (female.isSelected()) gender = "Female";

                // Show collected data

                JOptionPane.showMessageDialog(frame,

                        "Name: " + name + "\n" +

                        "Address: " + address + "\n" +

                        "Languages: " + languages + "\n" +

                        "Gender: " + gender,

                        "Submitted Data",

                        JOptionPane.INFORMATION_MESSAGE);

            }

        });

        // Add components to JFrame

        frame.add(nameLabel);

        frame.add(nameField);

        frame.add(addressLabel);

        frame.add(scrollPane);

        frame.add(languageLabel);

        frame.add(cb1);

        frame.add(cb2);

        frame.add(cb3);

        frame.add(genderLabel);

        frame.add(male);

        frame.add(female);

        frame.add(submitButton);

        // Make the frame visible

        frame.setVisible(true);

    }

}

output:

Conclusion

Swing components form the backbone of desktop GUI applications in Java. They offer a robust and extensible framework that balances ease of use with deep functionality. Whether it is through simple input elements like text fields and buttons, or more structured controls like checkboxes and radio buttons, Swing enables developers to build highly interactive, visually consistent, and platform-independent applications. Understanding these components is foundational for any Java developer involved in building desktop-based software systems.