Question 1(a) [3 marks]

Explain the difference between AWT and Swing.

Answer:

Feature	AWT	Swing
Platform	Platform dependent	Platform independent
Components	Heavy weight	Light weight
Look & Feel	Native OS look	Pluggable look & feel
Performance	Faster	Slower than AWT

Key Points:

Heavy vs Light: AWT uses native OS components, Swing uses pure Java
Appearance: AWT follows OS style, Swing offers consistent look across platforms
Features: Swing provides more advanced components like JTable, JTree

Mnemonic: "Swing Provides Lightweight Components"

Question 1(b) [4 marks]

Explain Mouse Motion Listener with example.

Answer:

MouseMotionListener interface handles mouse movement events in Java Swing applications.

Table: Mouse Motion Events

Method	Purpose
mouseDragged()	Called when mouse is dragged
mouseMoved()	Called when mouse is moved

Code Example:

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

class MouseMotionExample extends JFrame implements MouseMotionListener {
    JLabel label;
    
    MouseMotionExample() {
        label = new JLabel("Move mouse here");
        add(label);
        addMouseMotionListener(this);
        setSize(400, 300);
        setVisible(true);
    }
    
    public void mouseMoved(MouseEvent e) {
        label.setText("Mouse at: " + e.getX() + ", " + e.getY());
    }
    
    public void mouseDragged(MouseEvent e) {
        label.setText("Dragging at: " + e.getX() + ", " + e.getY());
    }
}

Mnemonic: "Mouse Motion Makes Dynamic"

Question 1(c) [7 marks]

Develop a program to create checkboxes for different courses belonging to a university such that the course selected would be displayed.

Answer:

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

public class CourseSelection extends JFrame implements ItemListener {
    JCheckBox java, python, cpp, web;
    JTextArea display;
    
    public CourseSelection() {
        setTitle("University Course Selection");
        setLayout(new FlowLayout());
        
        // Create checkboxes
        java = new JCheckBox("Java Programming");
        python = new JCheckBox("Python Programming");
        cpp = new JCheckBox("C++ Programming");
        web = new JCheckBox("Web Development");
        
        // Add listeners
        java.addItemListener(this);
        python.addItemListener(this);
        cpp.addItemListener(this);
        web.addItemListener(this);
        
        // Display area
        display = new JTextArea(10, 30);
        display.setEditable(false);
        
        // Add components
        add(new JLabel("Select Courses:"));
        add(java); add(python); add(cpp); add(web);
        add(new JScrollPane(display));
        
        setSize(400, 300);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    
    public void itemStateChanged(ItemEvent e) {
        String courses = "Selected Courses:\n";
        if(java.isSelected()) courses += "- Java Programming\n";
        if(python.isSelected()) courses += "- Python Programming\n";
        if(cpp.isSelected()) courses += "- C++ Programming\n";
        if(web.isSelected()) courses += "- Web Development\n";
        display.setText(courses);
    }
    
    public static void main(String[] args) {
        new CourseSelection();
    }
}

Key Features:

ItemListener: Detects checkbox state changes
Dynamic Display: Updates selected courses in real-time
Multiple Selection: Allows selecting multiple courses

Mnemonic: "Check Items Listen Dynamically"

Question 1(c) OR [7 marks]

Develop a program to Implement Traffic signal (Red, Green and Yellow) by using Swing components (Using JFrame, JRadioButton, ItemListener etc.)

Answer:

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

public class TrafficSignal extends JFrame implements ItemListener {
    JRadioButton red, green, yellow;
    ButtonGroup group;
    JPanel signalPanel;
    
    public TrafficSignal() {
        setTitle("Traffic Signal Simulator");
        setLayout(new BorderLayout());
        
        // Create radio buttons
        red = new JRadioButton("Red");
        green = new JRadioButton("Green"); 
        yellow = new JRadioButton("Yellow");
        
        // Group radio buttons
        group = new ButtonGroup();
        group.add(red); group.add(green); group.add(yellow);
        
        // Add listeners
        red.addItemListener(this);
        green.addItemListener(this);
        yellow.addItemListener(this);
        
        // Signal display panel
        signalPanel = new JPanel() {
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.setColor(Color.BLACK);
                g.fillRect(50, 50, 100, 200);
                
                // Draw circles
                g.setColor(red.isSelected() ? Color.RED : Color.GRAY);
                g.fillOval(65, 65, 70, 70);
                
                g.setColor(yellow.isSelected() ? Color.YELLOW : Color.GRAY);
                g.fillOval(65, 105, 70, 70);
                
                g.setColor(green.isSelected() ? Color.GREEN : Color.GRAY);
                g.fillOval(65, 145, 70, 70);
            }
        };
        
        JPanel controlPanel = new JPanel();
        controlPanel.add(red); controlPanel.add(yellow); controlPanel.add(green);
        
        add(controlPanel, BorderLayout.SOUTH);
        add(signalPanel, BorderLayout.CENTER);
        
        setSize(300, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    
    public void itemStateChanged(ItemEvent e) {
        signalPanel.repaint();
    }
    
    public static void main(String[] args) {
        new TrafficSignal();
    }
}

Diagram:

+----------------+
|  Traffic Box   |
|   ┌─────────┐  |
|   │   RED   │  |
|   ├─────────┤  |
|   │ YELLOW  │  |
|   ├─────────┤  |
|   │  GREEN  │  |
|   └─────────┘  |
+----------------+
  [R] [Y] [G]

Mnemonic: "Radio Buttons Paint Graphics"

Question 2(a) [3 marks]

Explain JDBC type-4 driver.

Answer:

JDBC Type-4 Driver (Native Protocol Driver)

Feature	Description
Type	Pure Java driver
Communication	Direct database protocol
Platform	Platform independent
Performance	Highest performance

Key Points:

Pure Java: No native code required
Direct Connection: Communicates directly with database
Network Protocol: Uses database's native network protocol
Best Performance: Fastest among all driver types

Mnemonic: "Pure Java Direct Protocol"

Question 2(b) [4 marks]

Explain Commonly used Methods of Component class.

Answer:

Table: Component Class Methods

Method	Purpose
add()	Adds component to container
setSize()	Sets component dimensions
setLayout()	Sets layout manager
setVisible()	Makes component visible/invisible
setBounds()	Sets position and size
getSize()	Returns component size

Key Features:

Layout Management: Controls component arrangement
Visibility Control: Shows/hides components
Size Management: Controls component dimensions
Container Operations: Manages child components

Mnemonic: "Add Set Get Visibility"

Question 2(c) [7 marks]

Develop a program using JDBC to display student's record (Enroll No, Name, Address, Mobile No and Email-ID) from table 'StuRec'.

Answer:

import java.sql.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class StudentRecordDisplay extends JFrame {
    JTable table;
    DefaultTableModel model;
    
    public StudentRecordDisplay() {
        setTitle("Student Records");
        
        // Create table model
        String[] columns = {"Enroll No", "Name", "Address", "Mobile", "Email"};
        model = new DefaultTableModel(columns, 0);
        table = new JTable(model);
        
        // Load data
        loadStudentData();
        
        add(new JScrollPane(table));
        setSize(600, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    
    private void loadStudentData() {
        try {
            // Database connection
            Class.forName("com.mysql.cj.jdbc.Driver");
            Connection con = DriverManager.getConnection(
                "jdbc:mysql://localhost:3306/university", "root", "password");
            
            // Execute query
            Statement stmt = con.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM StuRec");
            
            // Add data to table
            while(rs.next()) {
                String[] row = {
                    rs.getString("enrollno"),
                    rs.getString("name"),
                    rs.getString("address"),
                    rs.getString("mobile"),
                    rs.getString("email")
                };
                model.addRow(row);
            }
            
            con.close();
        } catch(Exception e) {
            JOptionPane.showMessageDialog(this, "Error: " + e.getMessage());
        }
    }
    
    public static void main(String[] args) {
        new StudentRecordDisplay();
    }
}

Database Table Structure:

CREATE TABLE StuRec (
    enrollno VARCHAR(20) PRIMARY KEY,
    name VARCHAR(50),
    address VARCHAR(100),
    mobile VARCHAR(15),
    email VARCHAR(50)
);

Mnemonic: "Connect Query Display Records"

Question 2(a) OR [3 marks]

Write down the advantages and disadvantages of JDBC.

Answer:

Table: JDBC Advantages and Disadvantages

Advantages	Disadvantages
Platform Independent	Performance Overhead
Database Independent	Complex for beginners
Standard API	SQL dependency
Supports transactions	Manual resource management

Key Points:

Portability: Works across different platforms and databases
Standardization: Uniform API for database operations
Performance: Additional layer causes overhead
Complexity: Requires proper resource management

Mnemonic: "Platform Independent Standard Complex"

Question 2(b) OR [4 marks]

Explain Border Layout.

Answer:

BorderLayout divides container into five regions: North, South, East, West, and Center.

Diagram:

+------------------+
|      NORTH       |
+-----+------+-----+
|WEST |CENTER| EAST|
+-----+------+-----+
|      SOUTH       |
+------------------+

Table: Border Layout Regions

Region	Position	Behavior
NORTH	Top	Preferred height, full width
SOUTH	Bottom	Preferred height, full width
EAST	Right	Preferred width, full height
WEST	Left	Preferred width, full height
CENTER	Middle	Takes remaining space

Code Example:

setLayout(new BorderLayout());
add(new JButton("North"), BorderLayout.NORTH);
add(new JButton("Center"), BorderLayout.CENTER);

Mnemonic: "North South East West Center"

Question 2(c) OR [7 marks]

Develop an application to store, update, fetch and delete data of Employee (NAME, AGE, SALARY and DEPARTMENT) using Hibernate CRUD operations.

Answer:

Employee Entity Class:

import javax.persistence.*;

@Entity
@Table(name = "employees")
public class Employee {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    
    private String name;
    private int age;
    private double salary;
    private String department;
    
    // Constructors, getters, setters
    public Employee() {}
    
    public Employee(String name, int age, double salary, String dept) {
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.department = dept;
    }
    
    // Getters and Setters
    public int getId() { return id; }
    public void setId(int id) { this.id = id; }
    
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    
    // ... other getters/setters
}

CRUD Operations Class:

import org.hibernate.*;
import org.hibernate.cfg.Configuration;

public class EmployeeCRUD {
    private SessionFactory factory;
    
    public EmployeeCRUD() {
        factory = new Configuration()
                    .configure("hibernate.cfg.xml")
                    .addAnnotatedClass(Employee.class)
                    .buildSessionFactory();
    }
    
    // CREATE
    public void saveEmployee(Employee emp) {
        Session session = factory.openSession();
        Transaction tx = session.beginTransaction();
        session.save(emp);
        tx.commit();
        session.close();
    }
    
    // READ
    public Employee getEmployee(int id) {
        Session session = factory.openSession();
        Employee emp = session.get(Employee.class, id);
        session.close();
        return emp;
    }
    
    // UPDATE
    public void updateEmployee(Employee emp) {
        Session session = factory.openSession();
        Transaction tx = session.beginTransaction();
        session.update(emp);
        tx.commit();
        session.close();
    }
    
    // DELETE
    public void deleteEmployee(int id) {
        Session session = factory.openSession();
        Transaction tx = session.beginTransaction();
        Employee emp = session.get(Employee.class, id);
        session.delete(emp);
        tx.commit();
        session.close();
    }
}

Mnemonic: "Save Get Update Delete Hibernate"

Question 3(a) [3 marks]

Explain Deployment Descriptor.

Answer:

Deployment Descriptor (web.xml) is configuration file for web applications containing servlet mappings, initialization parameters, and security settings.

Table: Deployment Descriptor Elements

Element	Purpose
<servlet>	Defines servlet configuration
<servlet-mapping>	Maps servlet to URL pattern
<init-param>	Sets initialization parameters
<welcome-file-list>	Default files to serve

Key Features:

Configuration: Central configuration for web app
Servlet Mapping: URL to servlet mapping
Parameters: Initialization and context parameters
Security: Authentication and authorization settings

Mnemonic: "Web XML Configuration Mapping"

Question 3(b) [4 marks]

Explain the difference between get and post method in servlet.

Answer:

Table: GET vs POST Methods

Feature	GET	POST
Data Location	URL query string	Request body
Data Size	Limited (2048 chars)	Unlimited
Security	Less secure (visible)	More secure
Caching	Can be cached	Not cached
Bookmarking	Can bookmark	Cannot bookmark
Purpose	Retrieve data	Submit/modify data

Key Points:

Visibility: GET data visible in URL, POST hidden
Capacity: POST can handle large data
Security: POST better for sensitive data
Usage: GET for fetching, POST for form submission

Mnemonic: "GET Visible Limited, POST Hidden Unlimited"

Question 3(c) [7 marks]

Develop a simple servlet program which maintains a counter for the number of times it has been accessed since its loading; initialize the counter using deployment descriptor.

Answer:

Servlet Code:

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class CounterServlet extends HttpServlet {
    private int counter;
    
    public void init() throws ServletException {
        String initialValue = getInitParameter("initialCount");
        counter = Integer.parseInt(initialValue);
    }
    
    protected void doGet(HttpServletRequest request, 
                        HttpServletResponse response) 
                        throws ServletException, IOException {
        
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        
        synchronized(this) {
            counter++;
        }
        
        out.println("<html><body>");
        out.println("<h2>Page Access Counter</h2>");
        out.println("<p>This page has been accessed " + counter + " times</p>");
        out.println("<p><a href='CounterServlet'>Refresh</a></p>");
        out.println("</body></html>");
        
        out.close();
    }
}

web.xml Configuration:

<?xml version="1.0" encoding="UTF-8"?>
<web-app>
    <servlet>
        <servlet-name>CounterServlet</servlet-name>
        <servlet-class>CounterServlet</servlet-class>
        <init-param>
            <param-name>initialCount</param-name>
            <param-value>0</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    
    <servlet-mapping>
        <servlet-name>CounterServlet</servlet-name>
        <url-pattern>/counter</url-pattern>
    </servlet-mapping>
</web-app>

Key Features:

Thread Safety: Synchronized counter increment
Initialization: Counter initialized from web.xml
Persistent: Counter maintained across requests
Configuration: Deployment descriptor setup

Mnemonic: "Initialize Synchronize Count Display"

Question 3(a) OR [3 marks]

Explain the life cycle of a servlet.

Answer:

Servlet Life Cycle Diagram:

stateDiagram-v2
  direction LR
    [*] --> Loading
    Loading --> init()
    init() --> service()
    service() --> service() : Multiple requests
    service() --> destroy()
    destroy() --> [*]

Table: Servlet Life Cycle Methods

Method	Purpose	Called
init()	Initialize servlet	Once at startup
service()	Handle requests	For each request
destroy()	Cleanup resources	Once at shutdown

Key Points:

Initialization: Called once when servlet loads
Service: Handles all client requests
Cleanup: Called before servlet unloads
Container Managed: Web container controls lifecycle

Mnemonic: "Initialize Service Destroy"

Question 3(b) OR [4 marks]

Explain Servlet Config class with suitable example.

Answer:

ServletConfig provides servlet-specific configuration information and initialization parameters.

Table: ServletConfig Methods

Method	Purpose
getInitParameter()	Gets init parameter value
getInitParameterNames()	Gets all parameter names
getServletContext()	Gets servlet context
getServletName()	Gets servlet name

Example:

public class ConfigServlet extends HttpServlet {
    String databaseURL, username;
    
    public void init() throws ServletException {
        ServletConfig config = getServletConfig();
        databaseURL = config.getInitParameter("dbURL");
        username = config.getInitParameter("dbUser");
    }
    
    protected void doGet(HttpServletRequest request, 
                        HttpServletResponse response) 
                        throws ServletException, IOException {
        
        PrintWriter out = response.getWriter();
        out.println("Database URL: " + databaseURL);
        out.println("Username: " + username);
    }
}

web.xml:

<servlet>
    <servlet-name>ConfigServlet</servlet-name>
    <servlet-class>ConfigServlet</servlet-class>
    <init-param>
        <param-name>dbURL</param-name>
        <param-value>jdbc:mysql://localhost:3306/test</param-value>
    </init-param>
    <init-param>
        <param-name>dbUser</param-name>
        <param-value>root</param-value>
    </init-param>
</servlet>

Mnemonic: "Config Gets Parameters Context"

Question 3(c) OR [7 marks]

Develop a simple program, when user select the subject code, name of the subject will be displayed using servlet and mysql database.

Answer:

HTML Form (index.html):

<!DOCTYPE html>
<html>
<head>
    <title>Subject Selection</title>
</head>
<body>
    <h2>Select Subject Code</h2>
    <form action="SubjectServlet" method="get">
        <select name="subjectCode">
            <option value="">Select Subject</option>
            <option value="4351603">4351603</option>
            <option value="4351604">4351604</option>
            <option value="4351605">4351605</option>
        </select>
        <input type="submit" value="Get Subject Name">
    </form>
</body>
</html>

Servlet Code:

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class SubjectServlet extends HttpServlet {
    
    protected void doGet(HttpServletRequest request, 
                        HttpServletResponse response) 
                        throws ServletException, IOException {
        
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        
        String subjectCode = request.getParameter("subjectCode");
        String subjectName = "";
        
        if(subjectCode != null && !subjectCode.equals("")) {
            try {
                Class.forName("com.mysql.cj.jdbc.Driver");
                Connection con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/university", "root", "password");
                
                PreparedStatement ps = con.prepareStatement(
                    "SELECT subject_name FROM subjects WHERE subject_code = ?");
                ps.setString(1, subjectCode);
                
                ResultSet rs = ps.executeQuery();
                if(rs.next()) {
                    subjectName = rs.getString("subject_name");
                }
                
                con.close();
            } catch(Exception e) {
                subjectName = "Error: " + e.getMessage();
            }
        }
        
        out.println("<html><body>");
        out.println("<h2>Subject Information</h2>");
        if(!subjectName.equals("")) {
            out.println("<p>Subject Code: " + subjectCode + "</p>");
            out.println("<p>Subject Name: " + subjectName + "</p>");
        } else {
            out.println("<p>Please select a subject code</p>");
        }
        out.println("<p><a href='index.html'>Back</a></p>");
        out.println("</body></html>");
    }
}

Database Table:

CREATE TABLE subjects (
    subject_code VARCHAR(10) PRIMARY KEY,
    subject_name VARCHAR(100)
);

INSERT INTO subjects VALUES 
('4351603', 'Advanced Java Programming'),
('4351604', 'Web Technology'),
('4351605', 'Database Management System');

Mnemonic: "Select Query Display Subject"

Question 4(a) [3 marks]

Explain JSP life cycle.

Answer:

JSP Life Cycle Diagram:

stateDiagram-v2
  direction LR
    [*] --> Translation
    Translation --> Compilation
    Compilation --> Loading
    Loading --> jspInit()
    jspInit() --> _jspService()
    _jspService() --> _jspService() : Multiple requests
    _jspService() --> jspDestroy()
    jspDestroy() --> [*]

Table: JSP Life Cycle Phases

Phase	Description
Translation	JSP to Servlet conversion
Compilation	Servlet to bytecode
Loading	Load servlet class
Initialization	jspInit() called
Request Processing	_jspService() handles requests
Destruction	jspDestroy() cleanup

Mnemonic: "Translate Compile Load Initialize Service Destroy"

Question 4(b) [4 marks]

Compare JSP and Servlet.

Answer:

Table: JSP vs Servlet Comparison

Feature	JSP	Servlet
Code Type	HTML with Java code	Pure Java code
Development	Easier for web designers	Better for Java developers
Compilation	Automatic	Manual
Modification	No restart needed	Restart required
Performance	Slower first request	Faster
Maintenance	Easier	More complex

Key Points:

Ease of Use: JSP easier for presentation layer
Performance: Servlet better for business logic
Flexibility: JSP better for dynamic content
Control: Servlet provides more control

Mnemonic: "JSP Easy HTML, Servlet Pure Java"

Question 4(c) [7 marks]

Develop a JSP web application to display student monthly attendance in each subject of current semester via enrolment number.

Answer:

Input Form (attendance.html):

<!DOCTYPE html>
<html>
<head>
    <title>Student Attendance</title>
</head>
<body>
    <h2>Check Student Attendance</h2>
    <form action="attendanceCheck.jsp" method="post">
        <table>
            <tr>
                <td>Enrollment Number:</td>
                <td><input type="text" name="enrollNo" required></td>
            </tr>
            <tr>
                <td>Month:</td>
                <td>
                    <select name="month" required>
                        <option value="">Select Month</option>
                        <option value="January">January</option>
                        <option value="February">February</option>
                        <option value="March">March</option>
                    </select>
                </td>
            </tr>
            <tr>
                <td colspan="2">
                    <input type="submit" value="Check Attendance">
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

JSP Page (attendanceCheck.jsp):

<%@ page import="java.sql.*" %>
<%@ page contentType="text/html;charset=UTF-8" %>

<html>
<head>
    <title>Attendance Report</title>
    <style>
        table { border-collapse: collapse; width: 100%; }
        th, td { border: 1px solid black; padding: 8px; text-align: center; }
        th { background-color: #f2f2f2; }
    </style>
</head>
<body>
    <h2>Monthly Attendance Report</h2>
    
    <%
        String enrollNo = request.getParameter("enrollNo");
        String month = request.getParameter("month");
        
        if(enrollNo != null && month != null) {
            try {
                Class.forName("com.mysql.cj.jdbc.Driver");
                Connection con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/university", "root", "password");
                
                // Get student info
                PreparedStatement ps1 = con.prepareStatement(
                    "SELECT name FROM students WHERE enroll_no = ?");
                ps1.setString(1, enrollNo);
                ResultSet rs1 = ps1.executeQuery();
                
                String studentName = "";
                if(rs1.next()) {
                    studentName = rs1.getString("name");
                }
                
                out.println("<p><strong>Student:</strong> " + studentName + 
                           " (" + enrollNo + ")</p>");
                out.println("<p><strong>Month:</strong> " + month + "</p>");
                
                // Get attendance data
                PreparedStatement ps2 = con.prepareStatement(
                    "SELECT s.subject_name, a.total_classes, a.attended_classes, " +
                    "ROUND((a.attended_classes/a.total_classes)*100, 2) as percentage " +
                    "FROM attendance a JOIN subjects s ON a.subject_code = s.subject_code " +
                    "WHERE a.enroll_no = ? AND a.month = ?");
                ps2.setString(1, enrollNo);
                ps2.setString(2, month);
                ResultSet rs2 = ps2.executeQuery();
                
                out.println("<table>");
                out.println("<tr><th>Subject</th><th>Total Classes</th>" +
                           "<th>Attended</th><th>Percentage</th><th>Status</th></tr>");
                
                while(rs2.next()) {
                    String subjectName = rs2.getString("subject_name");
                    int totalClasses = rs2.getInt("total_classes");
                    int attendedClasses = rs2.getInt("attended_classes");
                    double percentage = rs2.getDouble("percentage");
                    String status = percentage >= 75 ? "Good" : "Poor";
                    String rowColor = percentage >= 75 ? "lightgreen" : "lightcoral";
                    
                    out.println("<tr style='background-color:" + rowColor + "'>");
                    out.println("<td>" + subjectName + "</td>");
                    out.println("<td>" + totalClasses + "</td>");
                    out.println("<td>" + attendedClasses + "</td>");
                    out.println("<td>" + percentage + "%</td>");
                    out.println("<td>" + status + "</td>");
                    out.println("</tr>");
                }
                
                out.println("</table>");
                con.close();
                
            } catch(Exception e) {
                out.println("<p style='color:red'>Error: " + e.getMessage() + "</p>");
            }
        }
    %>
    
    <br>
    <a href="attendance.html">Check Another Student</a>
</body>
</html>

Database Tables:

CREATE TABLE students (
    enroll_no VARCHAR(20) PRIMARY KEY,
    name VARCHAR(50)
);

CREATE TABLE subjects (
    subject_code VARCHAR(10) PRIMARY KEY,
    subject_name VARCHAR(100)
);

CREATE TABLE attendance (
    id INT AUTO_INCREMENT PRIMARY KEY,
    enroll_no VARCHAR(20),
    subject_code VARCHAR(10),
    month VARCHAR(15),
    total_classes INT,
    attended_classes INT,
    FOREIGN KEY (enroll_no) REFERENCES students(enroll_no),
    FOREIGN KEY (subject_code) REFERENCES subjects(subject_code)
);

Mnemonic: "JSP Database Query Display Table"

Question 4(a) OR [3 marks]

Explain implicit objects in JSP.

Answer:

Table: JSP Implicit Objects

Object	Type	Purpose
request	HttpServletRequest	Gets request data
response	HttpServletResponse	Sends response
out	JspWriter	Output to client
session	HttpSession	Session management
application	ServletContext	Application scope
config	ServletConfig	Servlet configuration
pageContext	PageContext	Page scope access
page	Object	Current servlet instance
exception	Throwable	Error page exception

Key Features:

Automatic: Available without declaration
Scope Access: Different scope levels
Request Handling: Input/output operations
Session Management: User session tracking

Mnemonic: "Request Response Out Session Application"

Question 4(b) OR [4 marks]

Explain why JSP is preferred over servlet.

Answer:

Table: JSP Advantages over Servlet

Aspect	JSP Advantage
Development	Easier HTML integration
Maintenance	Separates presentation from logic
Compilation	Automatic compilation
Modification	No server restart needed
Design	Web designer friendly
Code Reuse	Tag libraries and custom tags

Key Points:

Separation of Concerns: Clear separation of presentation and business logic
Rapid Development: Faster development cycle
Designer Friendly: Web designers can work with HTML-like syntax
Automatic Features: Container handles compilation and lifecycle

Mnemonic: "Easy HTML Automatic Designer Friendly"

Question 4(c) OR [7 marks]

Develop a JSP program to display the grade of a student by accepting the marks of five subjects.

Answer:

Input Form (gradeInput.html):

<!DOCTYPE html>
<html>
<head>
    <title>Student Grade Calculator</title>
    <style>
        table { margin: auto; border-collapse: collapse; }
        td { padding: 10px; }
        input[type="number"] { width: 100px; }
        input[type="submit"] { padding: 10px 20px; }
    </style>
</head>
<body>
    <h2 style="text-align: center;">Student Grade Calculator</h2>
    <form action="gradeCalculator.jsp" method="post">
        <table border="1">
            <tr>
                <td>Student Name:</td>
                <td><input type="text" name="studentName" required></td>
            </tr>
            <tr>
                <td>Subject 1 Marks:</td>
                <td><input type="number" name="marks1" min="0" max="100" required></td>
            </tr>
            <tr>
                <td>Subject 2 Marks:</td>
                <td><input type="number" name="marks2" min="0" max="100" required></td>
            </tr>
            <tr>
                <td>Subject 3 Marks:</td>
                <td><input type="number" name="marks3" min="0" max="100" required></td>
            </tr>
            <tr>
                <td>Subject 4 Marks:</td>
                <td><input type="number" name="marks4" min="0" max="100" required></td>
            </tr>
            <tr>
                <td>Subject 5 Marks:</td>
                <td><input type="number" name="marks5" min="0" max="100" required></td>
            </tr>
            <tr>
                <td colspan="2" style="text-align: center;">
                    <input type="submit" value="Calculate Grade">
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

JSP Grade Calculator (gradeCalculator.jsp):

<%@ page contentType="text/html;charset=UTF-8" %>

<html>
<head>
    <title>Grade Result</title>
    <style>
        .result-table { 
            margin: auto; 
            border-collapse: collapse; 
            margin-top: 20px;
        }
        .result-table th, .result-table td { 
            border: 1px solid black; 
            padding: 10px; 
            text-align: center; 
        }
        .result-table th { background-color: #f2f2f2; }
        .grade-A { background-color: #90EE90; }
        .grade-B { background-color: #87CEEB; }
        .grade-C { background-color: #F0E68C; }
        .grade-D { background-color: #FFA07A; }
        .grade-F { background-color: #FFB6C1; }
    </style>
</head>
<body>
    <h2 style="text-align: center;">Grade Report</h2>
    
    <%
        String studentName = request.getParameter("studentName");
        
        // Get marks
        int marks1 = Integer.parseInt(request.getParameter("marks1"));
        int marks2 = Integer.parseInt(request.getParameter("marks2"));
        int marks3 = Integer.parseInt(request.getParameter("marks3"));
        int marks4 = Integer.parseInt(request.getParameter("marks4"));
        int marks5 = Integer.parseInt(request.getParameter("marks5"));
        
        // Calculate total and percentage
        int totalMarks = marks1 + marks2 + marks3 + marks4 + marks5;
        double percentage = totalMarks / 5.0;
        
        // Determine grade
        String grade;
        String gradeClass;
        if(percentage >= 90) {
            grade = "A+";
            gradeClass = "grade-A";
        } else if(percentage >= 80) {
            grade = "A";
            gradeClass = "grade-A";
        } else if(percentage >= 70) {
            grade = "B";
            gradeClass = "grade-B";
        } else if(percentage >= 60) {
            grade = "C";
            gradeClass = "grade-C";
        } else if(percentage >= 50) {
            grade = "D";
            gradeClass = "grade-D";
        } else {
            grade = "F";
            gradeClass = "grade-F";
        }
        
        // Determine result
        String result = percentage >= 50 ? "PASS" : "FAIL";
    %>
    
    <table class="result-table">
        <tr>
            <th colspan="2">Student Information</th>
        </tr>
        <tr>
            <td><strong>Name:</strong></td>
            <td><%= studentName %></td>
        </tr>
        <tr>
            <th colspan="2">Subject-wise Marks</th>
        </tr>
        <tr>
            <td>Subject 1</td>
            <td><%= marks1 %></td>
        </tr>
        <tr>
            <td>Subject 2</td>
            <td><%= marks2 %></td>
        </tr>
        <tr>
            <td>Subject 3</td>
            <td><%= marks3 %></td>
        </tr>
        <tr>
            <td>Subject 4</td>
            <td><%= marks4 %></td>
        </tr>
        <tr>
            <td>Subject 5</td>
            <td><%= marks5 %></td>
        </tr>
        <tr>
            <th colspan="2">Result Summary</th>
        </tr>
        <tr>
            <td><strong>Total Marks:</strong></td>
            <td><%= totalMarks %> / 500</td>
        </tr>
        <tr>
            <td><strong>Percentage:</strong></td>
            <td><%= String.format("%.2f", percentage) %>%</td>
        </tr>
        <tr class="<%= gradeClass %>">
            <td><strong>Grade:</strong></td>
            <td><%= grade %></td>
        </tr>
        <tr>
            <td><strong>Result:</strong></td>
            <td><%= result %></td>
        </tr>
    </table>
    
    <div style="text-align: center; margin-top: 20px;">
        <a href="gradeInput.html">Calculate Another Grade</a>
    </div>
</body>
</html>

Grade Scale Table:

Percentage	Grade	Description
90-100	A+	Excellent
80-89	A	Very Good
70-79	B	Good
60-69	C	Average
50-59	D	Below Average
0-49	F	Fail

Mnemonic: "Calculate Total Percentage Grade Result"

Question 5(a) [3 marks]

Explain Aspect-oriented programming (AOP).

Answer:

AOP is programming paradigm that separates cross-cutting concerns from business logic using aspects.

Table: AOP Core Concepts

Concept	Description
Aspect	Module encapsulating cross-cutting concern
Join Point	Point in program execution
Pointcut	Set of join points
Advice	Action taken at join point
Weaving	Process of applying aspects

Key Benefits:

Separation: Separates business logic from system services
Modularity: Improves code modularity
Reusability: Cross-cutting concerns are reusable
Maintenance: Easier to maintain and modify

Mnemonic: "Aspect Join Pointcut Advice Weaving"

Question 5(b) [4 marks]

List various features of Servlet.

Answer:

Table: Servlet Features

Feature	Description
Platform Independent	Runs on any server supporting Java
Server Independent	Works with different web servers
Protocol Independent	Supports HTTP, HTTPS, FTP
Persistent	Remains in memory between requests
Robust	Strong memory management
Secure	Built-in security features
Portable	Write once, run anywhere
Powerful	Full Java API access

Key Points:

Performance: Better performance than CGI
Memory Management: Efficient memory usage
Multithreading: Handles multiple requests simultaneously
Extensible: Can be extended for specific protocols

Mnemonic: "Platform Server Protocol Persistent Robust"

Question 5(c) [7 marks]

Explain Model layer, View layer and Controller layer in details.

Answer:

MVC Architecture Diagram:

graph TB
    U[User] --> C[Controller]
    C --> M[Model]
    M --> C
    C --> V[View]
    V --> U
    
    subgraph "MVC Layers"
        M
        V
        C
    end

Table: MVC Layer Details

Layer	Responsibility	Components	Purpose
Model	Data and business logic	Entities, DAOs, Services	Data management
View	Presentation layer	JSP, HTML, CSS	User interface
Controller	Request handling	Servlets, Actions	Flow control

Model Layer Details:

Data Access: Database operations and data persistence
Business Logic: Core application logic and rules
Validation: Data validation and integrity checks
Entity Classes: Java beans representing data structures

Example Model:

public class Student {
    private String enrollNo;
    private String name;
    private double marks;
    
    // Business logic
    public String calculateGrade() {
        if(marks >= 90) return "A";
        else if(marks >= 80) return "B";
        else if(marks >= 70) return "C";
        else return "D";
    }
}

View Layer Details:

Presentation: User interface rendering
Display Logic: How data is presented to user
User Interaction: Forms, buttons, navigation
Responsive Design: Adapts to different devices

Controller Layer Details:

Request Handling: Processes user requests
Flow Control: Determines next view to display
Model Coordination: Calls appropriate model methods
Response Generation: Prepares response for user

Example Controller:

@WebServlet("/student")
public class StudentController extends HttpServlet {
    protected void doGet(HttpServletRequest request, 
                        HttpServletResponse response) {
        String action = request.getParameter("action");
        
        if("view".equals(action)) {
            // Get data from model
            Student student = studentService.getStudent(enrollNo);
            // Set in request scope
            request.setAttribute("student", student);
            // Forward to view
            RequestDispatcher rd = request.getRequestDispatcher("student.jsp");
            rd.forward(request, response);
        }
    }
}

Benefits of MVC:

Separation of Concerns: Clear responsibility division
Maintainability: Easier to maintain and modify
Testability: Each layer can be tested independently
Scalability: Supports large application development
Team Development: Multiple developers can work simultaneously

Mnemonic: "Model Data View Present Controller Handle"

Question 5(a) OR [3 marks]

Explain Features in Spring Boot.

Answer:

Table: Spring Boot Features

Feature	Description
Auto Configuration	Automatic configuration based on dependencies
Starter Dependencies	Curated set of dependencies
Embedded Servers	Built-in Tomcat, Jetty servers
Production Ready	Health checks, metrics, monitoring
No XML Configuration	Annotation-based configuration
Developer Tools	Hot reloading, automatic restart

Key Benefits:

Rapid Development: Quick project setup and development
Convention over Configuration: Sensible defaults
Microservices Ready: Easy microservices development
Cloud Native: Ready for cloud deployment

Mnemonic: "Auto Starter Embedded Production Annotation Developer"

Question 5(b) OR [4 marks]

Write Short note on JSP scripting elements.

Answer:

Table: JSP Scripting Elements

Element	Syntax	Purpose	Example
Scriptlet	`<% %>`	Java code execution	`<% int x = 10; %>`
Expression	`<%= %>`	Output value	`<%= x + 5 %>`
Declaration	`<%! %>`	Variable/method declaration	`<%! int count = 0; %>`
Directive	`<%@ %>`	Page configuration	`<%@ page import="java.util.*" %>`
Comment	`<%-- --%>`	JSP comments	`<%-- This is comment --%>`

Examples:

<%-- JSP Comment --%>
<%@ page contentType="text/html" %>

<%! 
    // Declaration - instance variable
    private int counter = 0;
    
    // Declaration - method
    public String getMessage() {
        return "Hello JSP!";
    }
%>

<html>
<body>
    <% 
        // Scriptlet - Java code
        String name = "Student";
        counter++;
    %>
    
    <h1><%= getMessage() %></h1>
    <p>Welcome <%= name %>!</p>
    <p>Page visited <%= counter %> times</p>
</body>
</html>

Key Points:

Scriptlet: Contains Java statements
Expression: Evaluates and outputs result
Declaration: Creates instance variables/methods
Directive: Provides page-level information

Mnemonic: "Script Express Declare Direct Comment"

Question 5(c) OR [7 marks]

Explain Dependency injection (DI) and Plain Old Java Object (POJO) in details.

Answer:

Dependency Injection (DI):

Dependency Injection is design pattern where objects receive their dependencies from external source rather than creating them internally.

Table: DI Types

Type	Description	Example
Constructor Injection	Dependencies via constructor	`public Service(Repository repo)`
Setter Injection	Dependencies via setter methods	`setRepository(Repository repo)`
Field Injection	Direct field injection	`@Autowired Repository repo`

DI Example:

// Without DI - Tight coupling
public class StudentService {
    private StudentRepository repo = new StudentRepository(); // Hard dependency
    
    public Student getStudent(String id) {
        return repo.findById(id);
    }
}

// With DI - Loose coupling
public class StudentService {
    private StudentRepository repo;
    
    // Constructor injection
    public StudentService(StudentRepository repo) {
        this.repo = repo;
    }
    
    public Student getStudent(String id) {
        return repo.findById(id);
    }
}

Spring DI Configuration:

@Service
public class StudentService {
    @Autowired
    private StudentRepository repository;
    
    public List<Student> getAllStudents() {
        return repository.findAll();
    }
}

@Repository
public class StudentRepository {
    public List<Student> findAll() {
        // Database operations
        return studentList;
    }
}

Plain Old Java Object (POJO):

POJO is simple Java object that doesn't inherit from any specific framework classes or implement specific interfaces.

POJO Characteristics:

No inheritance: Doesn't extend framework classes
No interfaces: Doesn't implement framework interfaces
No annotations: Can work without framework annotations
Simple: Contains only business logic and data

POJO Example:

// This is a POJO
public class Student {
    private String enrollNo;
    private String name;
    private int age;
    private String course;
    
    // Default constructor
    public Student() {}
    
    // Parameterized constructor
    public Student(String enrollNo, String name, int age, String course) {
        this.enrollNo = enrollNo;
        this.name = name;
        this.age = age;
        this.course = course;
    }
    
    // Getters and Setters
    public String getEnrollNo() {
        return enrollNo;
    }
    
    public void setEnrollNo(String enrollNo) {
        this.enrollNo = enrollNo;
    }
    
    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
    }
    
    // Business methods
    public boolean isEligibleForExam() {
        return age >= 18;
    }
    
    public String getStudentInfo() {
        return "Student: " + name + " (" + enrollNo + "), Course: " + course;
    }
}

Benefits of DI:

Loose Coupling: Reduces dependencies between classes
Testability: Easy to inject mock objects for testing
Flexibility: Easy to change implementations
Maintainability: Easier to maintain and extend code

Benefits of POJO:

Simplicity: Easy to understand and maintain
Testability: Simple to unit test
Portability: Can be used across different frameworks
Lightweight: No framework overhead

DI and POJO Together:

// POJO Entity
public class Student {
    private String name;
    private String email;
    // constructors, getters, setters
}

// Service with DI
@Service
public class StudentService {
    @Autowired
    private StudentRepository repository;
    
    public Student createStudent(String name, String email) {
        Student student = new Student(); // POJO creation
        student.setName(name);
        student.setEmail(email);
        return repository.save(student);
    }
}

Mnemonic: "DI Injects Dependencies, POJO Plain Objects"