June 2024 [Free] Solved BCS-053 Web Programming

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1. (a) Write a JSP program which will demonstrate the use of <jsp:forward> and <jsp:param> actions. (5 marks)

Answer:

JSP Program to Demonstrate <jsp:forward> and <jsp:param> Actions:

The <jsp:forward> action is used to forward a request from one JSP page to another resource, such as another JSP page, servlet, or HTML page. The <jsp:param> action is used within the <jsp:forward> action to pass parameters to the target resource.

Code Example:

Below is the JSP code demonstrating these actions:


<!-- Page1.jsp -->
<html>
<head>
    <title>JSP Forward Example</title>
</head>
<body>
    <h2>Welcome to Page1</h2>
    <p>Forwarding this request to Page2.jsp with parameters...</p>

    <!-- Forwarding request to Page2.jsp with parameters -->
    <jsp:forward page="Page2.jsp">
        <jsp:param name="username" value="JohnDoe" />
        <jsp:param name="userrole" value="Admin" />
    </jsp:forward>
</body>
</html>


<!-- Page2.jsp -->
<html>
<head>
    <title>JSP Forwarded Page</title>
</head>
<body>
    <h2>Welcome to Page2</h2>

    <!-- Displaying the parameters passed from Page1.jsp -->
    <p>Username: <%= request.getParameter("username") %></p>
    <p>User Role: <%= request.getParameter("userrole") %></p>
</body>
</html>

Explanation:

Page1.jsp: This page forwards the request to Page2.jsp using the <jsp:forward> action. It also passes two parameters: "username" and "userrole" using the <jsp:param> action.
Page2.jsp: This page retrieves and displays the parameters passed from Page1.jsp using the request.getParameter() method.

Output:

When accessing Page1.jsp, the user sees a message that the request is being forwarded to Page2.jsp.
On Page2.jsp, the user sees the values of the parameters "username" and "userrole" displayed as follows:
- Username: JohnDoe
- User Role: Admin

1. (b) What is a safe method? Is the GET method a safe method? Give reasons in support of your answer. (3 marks)

Answer:

A safe method in the context of HTTP is a method that does not modify the state of the server. Safe methods are used for retrieving data without causing any side effects on the server's resources.

Is the GET Method a Safe Method?

Yes, the GET method is considered a safe method.

Reason:

The GET method is used to request data from a specified resource. It does not alter or modify the resource on the server.
Since it only retrieves data, it does not cause any side effects, such as creating, updating, or deleting resources.
GET requests are idempotent, meaning that making the same request multiple times will have the same effect as making it once, ensuring that the server state remains unchanged.

Example:

Consider the following GET request:


GET /products?category=electronics HTTP/1.1
Host: www.example.com

This request fetches a list of electronics products but does not make any changes to the server's data or state.

Because the GET method is non-intrusive and only retrieves data without modifying server resources, it is classified as a safe method in the HTTP protocol.

1. (c) Explain how errors are handled at the application level in JSP programs, with the help of a program fragment. (4 marks)

Answer:

Error Handling in JSP:

In JSP (JavaServer Pages), errors are handled at the application level using error pages. These pages are configured to display user-friendly messages when exceptions occur. Error handling can be implemented in two ways:

Declaring an error page in the JSP file where the exception occurs.
Using the <error-page> element in the web.xml deployment descriptor.

Example Program Fragment:

Below is an example of handling errors in JSP using an error page.

1. Main JSP File (`main.jsp`):


<%@ page errorPage="error.jsp" %>
<html>
<head><title>Main Page</title></head>
<body>
    <h1>Welcome to the Main Page</h1>
    <p>Triggering an error:</p>
    <% 
        int result = 10 / 0; // This will throw an ArithmeticException 
    %>
</body>
</html>

2. Error Page (`error.jsp`):


<%@ page isErrorPage="true" %>
<html>
<head><title>Error Page</title></head>
<body>
    <h1>An Error Occurred</h1>
    <p>Error Details:</p>
    <p><%= exception.getMessage() %></p>
</body>
</html>

The <%@ page errorPage="error.jsp" %> directive in the main JSP file specifies the error page to be displayed if an exception occurs.
The error page (`error.jsp`) includes the directive <%@ page isErrorPage="true" %> to indicate that it can handle exceptions.
When an exception is thrown (e.g., division by zero), the control is transferred to the error page, which displays a custom error message along with details of the exception using the `exception` object.

Error handling in JSP ensures that users are presented with meaningful error messages while hiding the technical details of the exception, enhancing the robustness and usability of the application.

1. (d) Why do we need XML? Write advantages of XML over HTML. (5 marks)

Answer:

XML (eXtensible Markup Language) is essential for structuring, storing, and transporting data in a platform-independent manner. It provides a flexible way to create information formats and share structured data across different systems, particularly over the internet.

Advantages of XML Over HTML:

Data Storage vs. Presentation:
HTML is designed for displaying data, while XML is used for storing and structuring data. XML separates content from presentation.
Custom Tags:
XML allows the creation of user-defined tags, whereas HTML has a fixed set of predefined tags.
Self-Descriptive Nature:
XML documents are self-descriptive as they provide both data and the structure of the data, making them easier to understand.
Data Validation:
XML supports data validation using DTD (Document Type Definition) and XML Schema, ensuring data integrity.
Platform Independence:
XML is platform-independent and can be used to transfer data between different systems, regardless of the operating system or software.
Extensibility:
XML can be extended and customized as per application requirements, while HTML is rigid in its structure.

While HTML focuses on how data is presented, XML provides a framework for structuring and transporting data, making it highly suitable for modern web applications that require dynamic data handling and interoperability.

1. (e) What is web container? Name any three web containers. (3 marks)

Answer:

A web container, also known as a servlet container, is a component of a web server or application server that provides the runtime environment for Java Servlets, JSP (JavaServer Pages), and other web-based Java components. It manages the lifecycle of servlets, maps URLs to specific servlets, and facilitates communication between the client and the server.

Responsibilities of a Web Container:

Loading, initializing, and managing the lifecycle of servlets and JSPs.
Handling client requests and directing them to the appropriate servlet or JSP.
Providing support for session management, security, and resource allocation.

Examples of Web Containers:

Apache Tomcat: A widely used open-source web container for running Java Servlets and JSPs.
JBoss EAP (WildFly): A Java-based application server with built-in web container capabilities.
GlassFish: An open-source application server that supports Java EE, including servlet and JSP technologies.

2. (a) What are JSP Implicit objects? Explain the use of any two implicit objects. (4 marks)

Answer:

JSP Implicit objects are predefined objects provided by the JSP container that developers can use directly in a JSP page without needing to declare or instantiate them. These objects simplify development by providing access to various functionalities like request handling, response generation, and session management.

Key Features of JSP Implicit Objects:

Automatically available in JSP pages without the need for explicit declaration.
Facilitate interaction with the server, client, and session objects.

Examples and Usage:

request: This object represents the client's request and is an instance of javax.servlet.http.HttpServletRequest. It provides access to request parameters, headers, and attributes.
```
Example:
<%
    String userName = request.getParameter("username");
    out.println("Welcome, " + userName);
%>
                
```

session: This object represents the current session and is an instance of javax.servlet.http.HttpSession. It is used to store user-specific data across multiple requests.


Example:
<%
    session.setAttribute("user", "John Doe");
    String user = (String) session.getAttribute("user");
    out.println("User: " + user);
%>

2. (b) Differentiate between the following: (i) Static web pages and dynamic web pages. (ii) 2-Tier architecture and 3-Tier architecture. (6 marks)

Answer:

(i) Static Web Pages vs. Dynamic Web Pages:

Aspect	Static Web Pages	Dynamic Web Pages
Content	Fixed content that does not change unless manually updated.	Content can change dynamically based on user interaction or server-side logic.
Technology	Built using HTML, CSS, and sometimes JavaScript.	Uses server-side scripting languages like PHP, ASP.NET, or frameworks like Django.
Interaction	Minimal user interaction, typically read-only.	Highly interactive, allowing data submission, processing, and retrieval.
Performance	Faster loading due to static content.	Relatively slower due to real-time data generation.

(ii) 2-Tier Architecture vs. 3-Tier Architecture:

Aspect	2-Tier Architecture	3-Tier Architecture
Structure	Consists of a client and a server.	Includes three layers: client, application server, and database server.
Logic Distribution	Business logic and database logic reside on the server.	Business logic resides in the application server; the database layer is separate.
Scalability	Limited scalability due to tight coupling of client and server.	Highly scalable as the layers are independent and can be modified separately.
Example	Database client accessing a database server directly.	A web browser (client) interacting with a web server and a database server.

3. (a) Explain WML Navigation Elements with the help of WML programs. (5 marks)

Answer:

WML (Wireless Markup Language) supports navigation elements that help in creating user-friendly navigation structures for wireless devices. These include:

Cards: Each WML document is divided into multiple cards, which are containers for user interface elements and content.
Decks: A collection of cards constitutes a deck, which is a complete WML file.
Links: Used to navigate between cards and decks, enabling users to interact with the application.

Below is an example WML program demonstrating navigation elements:


<?xml version="1.0"?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN"
    "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
    <card id="card1" title="Welcome">
        <p>Welcome to WML Navigation!</p>
        <a href="#card2">Go to Next Card</a>
    </card>
    <card id="card2" title="Navigation">
        <p>This is the second card. Choose your option:</p>
        <a href="#card1">Back to First Card</a><br/>
        <a href="#card3">Go to Third Card</a>
    </card>
    <card id="card3" title="Thank You">
        <p>Thank you for exploring WML!</p>
        <a href="#card1">Start Over</a>
    </card>
</wml>

Explanation:

Card 1: Displays a welcome message and provides a link to navigate to Card 2.
Card 2: Offers navigation to both Card 1 and Card 3 with links.
Card 3: Displays a thank-you message and provides an option to start over by linking back to Card 1.

3. (b) Write an HTML program using `<details>` and `<summary>` tag. Also explain both the tags. (5 marks)

Answer:

<details>: This tag is used to create a disclosure widget that users can open and close to view additional content.
<summary>: This tag is used as the visible heading or summary for the <details> content. Clicking on it toggles the visibility of the content within the <details> tag.

Below is an HTML program demonstrating the use of these tags:


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Details and Summary Example</title>
</head>
<body>
    <h1>Details and Summary Example</h1>
    <details>
        <summary>What is HTML?</summary>
        <p>HTML (HyperText Markup Language) is the standard language for creating webpages. It provides the basic structure of a website, which can be enhanced using CSS and JavaScript.</p>
    </details>
    <details>
        <summary>Benefits of HTML</summary>
        <ul>
            <li>Easy to learn and use</li>
            <li>Supports multimedia content</li>
            <li>Works on all modern browsers</li>
        </ul>
    </details>
</body>
</html>

The first <details> tag provides information about HTML when expanded, with a <summary> "What is HTML?" serving as the heading.
The second <details> tag lists the benefits of HTML, with "Benefits of HTML" as its heading.
Clicking on the <summary> toggles the visibility of the content inside the respective <details> block.

4. Explain the following with the help of an example/diagram, if needed: (10 marks)

(a) WAP Protocol Stack

Answer:

The WAP (Wireless Application Protocol) protocol stack consists of layers that are similar to the OSI model, optimized for wireless communication. The key layers are:

Application Layer: Manages user interface and application services using WML, WMLScript.
Session Layer: Provides connection management using WSP (Wireless Session Protocol).
Transaction Layer: Ensures secure data transfer with WTP (Wireless Transaction Protocol).
Security Layer: Uses WTLS (Wireless Transport Layer Security) for secure communication.
Transport Layer: Relies on UDP for data transmission.


WAP Protocol Stack Diagram:
+-----------------+
| Application     |
+-----------------+
| Session         |
+-----------------+
| Transaction     |
+-----------------+
| Security        |
+-----------------+
| Transport (UDP) |
+-----------------+

(b) Deployment Descriptor

Answer:

The deployment descriptor is an XML file (web.xml) used in Java web applications to configure settings such as servlets, filters, and listeners. It resides in the WEB-INF directory.

Example:


<web-app>
    <servlet>
        <servlet-name>MyServlet</servlet-name>
        <servlet-class>com.example.MyServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyServlet</servlet-name>
        <url-pattern>/myservlet</url-pattern>
    </servlet-mapping>
</web-app>

Answer:

XSLT (Extensible Stylesheet Language Transformations) is used to transform XML data into a different format such as HTML, text, or another XML document.

Example:


XML File:
<data>
    <name>John Doe</name>
    <email>johndoe@example.com</email>
</data>

XSLT File:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:template match="/">
        <html>
            <body>
                <h1>User Information</h1>
                <p>Name: <xsl:value-of select="data/name" /></p>
                <p>Email: <xsl:value-of select="data/email" /></p>
            </body>
        </html>
    </xsl:template>
</xsl:stylesheet>

(d) JSP Scriptlets

Answer:

JSP Scriptlets are blocks of Java code embedded in JSP pages, enclosed within <% ... %>. They are executed on the server side.

Example:


<%@ page language="java" %>
<html>
<body>
    <h1>Current Date and Time</h1>
    <% 
        java.util.Date date = new java.util.Date(); 
        out.println("Current Date and Time: " + date.toString());
    %>
</body>
</html>

5. (a) Explain the features of the following web technologies: (i) Mashups (ii) Rich Internet Applications (iii) Web services (6 marks)

Answer:

(i) Mashups

Mashups are web applications that combine data or functionality from multiple external sources into a single user interface. They allow for easy integration of various services, enabling users to interact with different types of content or services in one platform. Common examples include combining maps with real-time data like weather or social media feeds.

Features:

Combines data from multiple APIs or web services.
Provides new functionality or user experiences.
Enhances user interaction by blending content from different sources.

(ii) Rich Internet Applications (RIAs)

Rich Internet Applications (RIAs) are web applications that offer a rich user experience similar to desktop applications. They typically use AJAX, Flash, or Silverlight to provide interactive and dynamic content. Unlike traditional web applications that rely on page reloads, RIAs provide seamless and fluid experiences by allowing data updates without reloading the page.

Features:

Interactive and dynamic user interfaces.
Responsive and fast performance.
Minimal page reloads, utilizing AJAX or JavaScript frameworks.
Can run in the browser or use browser plugins like Flash or Silverlight.

(iii) Web Services

Web services are standardized ways of integrating web-based applications using open standards. They allow different applications, often on different platforms, to communicate with each other by exchanging data in a standard format, such as XML or JSON. Web services are typically used for exchanging information between systems over the internet or a network.

Features:

Platform-independent communication.
Uses open standards like HTTP, XML, and SOAP for communication.
Supports data exchange in a format like XML, JSON, or SOAP.
Enables interoperability between different applications or systems.

5. (b) Write a JSP program which may print the series of odd numbers from 1 to 100. Also find the sum of these numbers. (4 marks)

Answer:

Here is a JSP program that prints the series of odd numbers from 1 to 100 and calculates their sum:


<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<html>
<head>
    <title>Odd Numbers Series</title>
</head>
<body>
    <h2>Series of Odd Numbers from 1 to 100</h2>
    <p>
        <%
            int sum = 0;
            out.println("Odd Numbers: ");
            for (int i = 1; i <= 100; i += 2) {
                out.print(i + " ");
                sum += i;
            }
        %>
    </p>
    <p>
        <strong>Sum of Odd Numbers from 1 to 100: </strong> 
        <%
            out.println(sum);
        %>
    </p>
</body>
</html>

Suggetested Articles

June 2024 [Free] Solved BCS-053 Web Programming

1. (a) Write a JSP program which will demonstrate the use of <jsp:forward> and <jsp:param> actions. (5 marks)

JSP Program to Demonstrate <jsp:forward> and <jsp:param> Actions:

Code Example:

Explanation:

Output:

1. (b) What is a safe method? Is the GET method a safe method? Give reasons in support of your answer. (3 marks)

Is the GET Method a Safe Method?

Reason:

Example:

1. (c) Explain how errors are handled at the application level in JSP programs, with the help of a program fragment. (4 marks)

Error Handling in JSP:

Example Program Fragment:

1. Main JSP File (`main.jsp`):

2. Error Page (`error.jsp`):

1. (d) Why do we need XML? Write advantages of XML over HTML. (5 marks)

Advantages of XML Over HTML:

1. (e) What is web container? Name any three web containers. (3 marks)

Responsibilities of a Web Container:

Examples of Web Containers:

2. (a) What are JSP Implicit objects? Explain the use of any two implicit objects. (4 marks)

Key Features of JSP Implicit Objects:

Examples and Usage:

2. (b) Differentiate between the following: (i) Static web pages and dynamic web pages. (ii) 2-Tier architecture and 3-Tier architecture. (6 marks)

(i) Static Web Pages vs. Dynamic Web Pages:

(ii) 2-Tier Architecture vs. 3-Tier Architecture:

3. (a) Explain WML Navigation Elements with the help of WML programs. (5 marks)

3. (b) Write an HTML program using <details> and <summary> tag. Also explain both the tags. (5 marks)

4. Explain the following with the help of an example/diagram, if needed: (10 marks)

5. (a) Explain the features of the following web technologies: (i) Mashups (ii) Rich Internet Applications (iii) Web services (6 marks)

5. (b) Write a JSP program which may print the series of odd numbers from 1 to 100. Also find the sum of these numbers. (4 marks)

3. (b) Write an HTML program using `<details>` and `<summary>` tag. Also explain both the tags. (5 marks)