Java Servlets Tutorials

Java Servlets Tutorials For Beginners and Professionals

In this Java Servlets Tutorials For Beginners and Professionals article series, we are going to discuss all the basic, intermediate, and advanced concepts of Servlets with simple as well as real-time examples. 

This Servlets tutorial is for whom?

This Servlets tutorial is designed for beginners, students, and professional Java developers who want to learn and enhance their Servlet Skill step by step from scratch. These tutorials provide a hands-on approach to the subject with step-by-step program examples that will assist you to learn and put the acquired knowledge into practice.

What you will learn from this Java Servlets Tutorial?

Introduction to Web Application and Web Terminology

1. What is a Website?
2. What is the architecture of a Static and Dynamic Website?
3. What is a Java-Based Dynamic Website?
4. What is Web Client?
5. What is a Web Server?
6. How to Overcome the Limitations of Web Servers?
7. What are the General Duties of a Server-side Program in the context of a website?
8. What type of application can be developed using Java?
9. Understanding Tier Architecture
10. Understanding Server-Side Programming
11. Why Server-Side Programming?
12. Advantages of Server-Side Programs
13. Understanding Client-Server Architecture

Introduction to Java Servlets

1. What is not Servlet?
2. What is Servlet?
3. What is the need for Servlet Technology?
4. What is Web Container?
5. What can a Servlet do on a Java website?
6. What are the similarities between Static and Dynamic Webpages?
7. What are the Differences between Static and Dynamic Webpages?
8. What is Java Servlet?
9. What is a Servlet Container?
10. Advantages of Servlet
11. Features of Servlet
12. Difference Between Servlets and JSP
13. Why learn servlet?
14. Applications of Servlet
15. Java Servlets Architecture
16. Servlet Packages

HTTP Protocol

1. What are HTTP Protocols?
2. HTTP Request Headers
3. HTTP Response Format
4. Why do we need an HTTP response status code?
5. Methods of setting HTTPResponse Status Codes
6. Methods for Sending Error
7. Common Status Codes with Status Messages
8. Why HTTP Response Headers?
9. Requirements of HTTP Protocols
10. How HTTP Protocol is able to manage its Stateless nature?
11. HTTP Methods
12. What are HTTP request methods?
13. What is the difference between the GET and POST Methods?

Servlet API

1. Java Servlet API
2. Interfaces in javax.servlet package
3. Classes in javax.servlet package
4. Interfaces in javax.servlet.http package
5. Classes in javax.servlet.http package

Servlet Interface

1. Java Servlet Interface
2. Servlet Interface Methods
3. 1. init() method
4. 2. service() method
5. 3. getServletConfig() method
6. 4. getServletInfo() method
7. 5. destroy() method
8. Example: To understand the Java Servlet Interface

GenericServlet class

1. Java Generic Servlet
2. What are the limitations of the GenericServlet?
3. What is the general structure of a real servlet (used in real web-based Java projects in the industry)?
4. Methods of Generic Servlet class
5. Example to demonstrate Generic Servlet

HttpServlet class

1. What is HttpServlet?
2. Methods of HttpServlet class
3. Example to demonstrate HttpServlet
4. Different approaches for using the get and post method

Life Cycle of a Servlet

1. Understanding Servlet Life Cycle
2. General Structure of a Simple User-Defined Servlet
3. Instantiation phase of a Servlet
4. How is the Servlet Container loading and Instantiating the Servlet?
5. Initialization Phase of a Servlet
6. Servicing Phase of a Servlet
7. Destruction Phase of the Servlet
8. Servlet Life Cycle Methods

Steps to create a servlet example

1. What are the different steps involved in Java Web Applications?
2. Step 1: Web Application Directory Structure
3. Step 2: Develop the web resources (and helper files if any)
4. Step 3: Develop the deployment descriptor (web.xml)
5. Step 4: Configuring the application files.
6. What is the Purpose of the <servlet> tag?
7. What is the Purpose of the <servlet-mapping> tag?
8. How many names can a Servlet have in a Java Web Application?
9. Understanding the URL Patterns
10. Different Ways to Prepare Servlet in Java

Developing First Java Servlet Application?

1. First Java Servlet Application
2. What is response.setContentType(“text/html”) method call?
3. What happens if I placed the main() in our servlet program?
4. How the servlet program is executing without the main(-) method?
5. What happens if the programmer calls the destroy() method explicitly from the service(-,-) method of the servlet program?
6. What happens if the programmer calls the init(-) method explicitly from the service(-,-) method of the servlet program?
7. Explain specification
8. What is the difference between web applications and web site?
9. Explain static web resource programs and dynamic web resource programs
10. How do we identify whether a web resource program is client-side or server-side?
11. Explain about TOMCAT server

How does Servlet work?

1. How Does the Servlet Work in Java Application?
2. How web container handles the servlet request?
3. What is written inside the public service method?
4. What is written inside the protected service method?
5. Servlets flow of execution

User Interface Forms Design

1. Static Form Design
2. Dynamic Form Design

War File

1. What is a war file?
2. Advantages of the war file.
3. How to create a war file?
4. How to deploy the war file?
5. How to extract the war file manually?

Welcome-file-list in web.xml

1. Why Welcome File?
2. Explain <welcome-file-list> tag
3. Smooth Deployment
4. Load-on-startup
5. Advantage of load-on-servlet
6. Passing positive value
7. Passing negative value

Servlet IDE

Creating Servlet Example in Eclipse
Creating Servlet in MyEclipse IDE
Creating a servlet in NetBeans IDE

Servlet Communication

1. Why Servlet Communication?
2. Browser-Servlet Communication
3. Sending Error Messages
4. Request Redirection
5. Request Redirection by using Hyperlinks
6. Request Redirection by setting Response Headers
7. Request Redirection by using Send Redirect Mechanisms
8. Web Component Communication
9. Applet Servlet Communication

ServletRequest Interface

1. ServletRequest Interface
2. Methods of ServletRequest Interface
3. HttpServletRequest Interface
4. Methods of HttpServletRequest Interface
5. Example to understand ServletRequest Interface
6. Getting Parameter Values: getParameter() method
7. Getting parameter names and values: using getParameterNames() and getParameter() methods

RequestDispatcher in Servlet

1. RequestDispatcher in Servlet
2. Include Mechanism
3. Forward Mechanism
4. Methods of RequestDispatcher Interface
5. How to get the object of RequestDispatcher
6. Example of RequestDispatcher

Servlet Chaining

1. What is Servlet Chaining?
2. What is Request Dispatching in the context of a Java web application?
3. Develop a Java WEB application in which inter-servlet communication is implemented using the forward mechanism of request dispatching.
4. Example using Include Mechanism of Request Dispatcher
5. What are the Different Approaches to Creating a RequestDispatcher object in Java?
6. What is the difference between the getRequestDispatcher() and getNamedDispatcher() methods?
7. What is the difference between the RequestDispatcher object that is created based on the request object and the servletContext object?
8. What is Error Servlet?

Request Redirection in servlet

1. Request Redirection in Servlet: sendRedirect() method
2. Difference Between the Forward Mechanism and the Send Redirect Mechanism
3. An example demonstrating the sendRedirect method in servlet
4. Creating custom Google search using sendRedirect

ServletConfig Interface

1. ServletConfig Interface
2. Advantage of ServletConfig
3. ServletConfig methods
4. How to get the ServletConfig object?
5. Example of ServletConfig to get the initialization parameters

ServletContext Interface

1. ServletContext Interface
2. Advantages of ServletContext Interface
3. Usage of ServletContext Object
4. How to get the object of ServletContext?
5. Methods of ServletContext
6. What is ForeignContext?
7. Example of ServletContext

Attribute in Servlet

1. Why Attributes in Servlet?
2. Request Attribute in Servlet
3. Session Attribute in Servlet
4. Application Attribute in Servlet
5. Methods Used in Attributes
6. Example: Attributes in Servlet
7. Difference Between ServletConfig and ServletContext

Servlets Scopes

1. How many Servlet instances are created in a Java web application?
2. What is the lifetime of a servlet instance?
3. How many ServletConfig objects?
4. What is the lifetime of the ServletConfig object?
5. How many request objects?
6. What is the lifetime of the request object?
7. What are the different Servlet Scopes?
8. Request Scope of a Servlet
9. Who calls doGet(-,-) and doPost(-,-) ?
10. How are doGet() and doPost() methods implemented in Httpservlet?
11. What are the methods of the ServletConfig object?
12. How many interfaces does GenericServlet implement?
13. How many init() methods are implemented in GenericServlet?
14. Explain about ServletContext
15. Explain the ServletContext scope or application scope
16. Explain the ServletConfig object

Session Tracking Mechanisms in Servlets

1. How protocols are classified?
2. Understanding Stateless and Stateful protocols.
3. Why HTTP is designed as a stateless protocol? What is the problem if HTTP comes as a stateful protocol?
4. What is the purpose of session tracking/ session management?
5. What is a Session?
6. What is session tracking?
7. How to implement session tracking in a Java web application?
8. What happens in the background when the getSession() method is called on the HttpServletRequest object?
9. Examples of real-time implementation of session tracking.
10. Why do we need Session Tracking?
11. What are the different Session Tracking techniques?

Cookies Session Tracking Mechanism

1. Why Cookies?
2. How do Cookies work?
3. What are Cookies?
4. What about Security?
5. Types of Cookies
6. Working of Cookies in Java Servlet Application
7. How to Create, Modify, Get, and Delete the Cookie?
8. Cookie Class Constructor and Methods in Java Servlet
9. Basic Example of Cookies in Java Servlet Web Application
10. Advantages of Cookies
11. Disadvantages of Cookies
12. In which area cookies are used in a website?
13. Java Servlet Cookies Real-Time Example: Servlet Login and Logout

Hidden Form Field Session Tracking Mechanism

1. What is the Hidden Form Fields Session Tracking Mechanism?
2. Hidden Form Fields Real-world application examples
3. What is the difference between session management/session tracking and state management?
4. How hidden form fields are used in a Java web application?
5. Hidden Form Filed Example in Java Servlet Application.
6. Advantages of Hidden Form Fields based session tracking technique
7. Disadvantages of Hidden Form Fields based session tracking technique

URL Rewriting Session Tracking Mechanism

1. Why do we need the URL Rewriting Session Tracking Mechanism?
2. What is URL-Rewriting Session Tracking Mechanism?
3. How to Implement URL-Rewriting in Servlet?
4. Advantages of URL-Rewriting
5. Disadvantages of URL-Rewriting
6. URL Rewriting Example using Java Servlet
7. Difference Between HttpSession with Cookies and HttpSession with URL-Rewriting

HttpSession Session Tracking Mechanism

1. HttpSession Interface
2. Creating an HttpSession object in Servlet
3. Understanding getSession() and getSession(false) methods
4. HttpSession Methods
5. Advantages and Disadvantages of HttpSession Session Tracking Mechanism
6. Understanding HttpSession with an Example in Java Servlet
7. Login and Logout Example using HttpSession in Servlet

Event and Listener in Servlet

1. Events and Listeners in Servlet
2. Event classes
3. Event interfaces
4. ServletContextEvent
5. HttpSessionEvent
6. ServletRequestEvent
7. ServletContext AttributeEvent
8. HttpSessionBindingEvent
9. ServletRequestAttributeEvent

Servlet Wrappers

1. Why Servlet Wrappers?
2. Types of Servlet Wrappers.
3. Servlet RequestWrapper Example
4. Servlet ResponseWrapper Example

Servlet Filter

1. Why Servlet Filters?
2. What are the Filters?
3. How to use Filters in Servlet?
4. Advantages of Filters
5. Types of Filters in Servlet
6. Filter Interface
7. FilterChain Interface
8. FilterConfig Interface
9. Servlet Filter Example
10. Servlet Authentication Filter
11. Authentication Filter Example

CRUD in Servlet

1. Servlet CRUD example
2. Pagination in Servlet

Servlets Exception Handling

1. web.xml Configuration
2. Request Attributes − Errors/Exceptions
3. Error Handler Servlet Example

Servlet with Annotation

1. Why Servlet Annotations?
2. Types of Annotations
3. @WebServlet Annotation with Example
4. @WebInitParam Annotation with Example
5. @WebFilter Annotation with Example
6. @WebListener Annotation with Example

Servlet Input Output Stream classes

1. Servlet Input Stream Class
2. Constructors of ServletInputStream
3. Methods of ServletInputStream
4. Servlet Output Stream Class
5. Constructors of ServletOutputStream
6. Methods of ServletOutputStream
7. Servlet Input Output Stream Classes Example

SingleThreadModel interface

1. As Servlets are Multi-threaded. How SingleThread Model comes?
2. Requirement of SingleThreadModel
3. How to implement SingleThreadModel?
4. Example of SingleThreadModel Interface
5. Drawbacks of SingleThreadModel in Servlet

Server Side Include (SSI)

Servlets – Debugging

1. Message Logging
2. Using JDB Debugger
3. Using Comments
4. Client and Server Headers
5. Important Debugging Tips

Servlets – Internationalization

1. Detecting Locale
2. Languages Setting
3. Locale Specific Dates
4. Locale Specific Currency
5. Locale Specific Percentage

Real-time Development Examples:

Example of the Registration form in servlet
Example of Fetching Data From a Database
Improving Servlet performance to fetch records from the database
Example of uploading and downloading files to the server in servlet
Example of Sending email through JavaMail API in Servlet
Example of writing data into PDF using servlet
Example of Login Form in Servlet
Example to display images using Servlet
Example of Auto Page Refresh

Top 100 Servlet Interview Questions and Answers

What do we expect from you?

We will do our level best to cover all the Java-Servlets concepts, but in the meantime, if you have any specific concept in your mind that you want us to cover, then please leave it as a comment in the comment box, and we will definitely discuss that concept(s) in this Java Servlets Tutorials course.

Prerequisites to Learn Servlets:

It is mandatory to have Knowledge of Core Java, and the basics of HTML. 

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