Websites are collections of static files, for example, images, graphics, and HTML files. These websites are referred to as web applications if they provide dynamic functions when hosted on the servers.

Websites mostly work on a client-server paradigm where the client sends requests to the server, which, in turn, processes the queries and provides the desired outputs. This communication is done using the HTTP protocol. In this article, we will be taking a look at the difference between JSP and Servlet.

Servlets are the server-side programs written in Java, which implement the Servlet interface and handle all the client requests to that server. Servlet acts as the middle layer between the client requests and the applications hosted on the server. Servlets are used to collect data from the users, for example, forms, and also to create web pages dynamically and present the results.

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JSP, Java Server Pages, is also a technology similar to the Servlets and is used to create web applications. JSPs can be viewed as the extension of Servlets, as JSP is easier to maintain and provides more functionalities. Java Server Pages (JSPs) forms a fundamental part of the Java EE. 

In this article, let’s dive deeper and understand some important questions about JSP and servlet, like – advantages of JSP over Servlet, difference between JSP and servlet Javatpoint, and other details about servlets and JSP.

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What Are JSP and Servlet? 

Servlets, the backbone of web development, dynamically produce content and enable client-server interactions. They play an important role in developing resilient and scalable web applications, managing user inputs, and providing dynamic outputs. These Java-based components operate within Servlet engine containers and augment server functionality. 

Servlets are an essential component of Java’s server-side technology, processing requests, handling answers, and smoothly integrating with web servers. They are crucial in the development of responsive and interactive web applications due to their capacity to manage dynamic content and facilitate communication between clients and servers. 

JSP, an acronym for Java Server Pages, is an extensive collection of technologies, which are used to develop web pages. These web pages are developed by inserting Java codes into HTML pages by JSP tags. The collection can contain HTML, XML, or both with JSP actions and commands.

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JSP contains static as well as dynamic data, where dynamic data can be JSP elements, whereas the static data can be HTML, XML, SVG, or WYML files. Servlets generate dynamic content, interact with the client, and are maintained by Servlet engine containers. Servlets are used to extend the functions provided by the servers.

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What is JSP in Java? 

JSP Servlet is a powerful tool in the Java domain that enables the creation of dynamic and interactive web pages. JSP acts as a bridge between Java and web development, allowing Java code to be embedded directly into HTML pages using specific tags. This seamless connection enables developers to construct feature-rich online apps by combining the power of Java with the flexibility of HTML.

Java JSP and Servlet run on a server and execute the Java code included in the page before sending the HTML to the client’s browser. This dynamic method enables the creation of content based on user inputs, database queries, or other server-side logic. JSP allows for the integration of static data such as HTML, XML, and other file formats with dynamic components, resulting in a full web development solution.

JSP streamlines the development process, improves maintainability, and encourages scalability by clearly separating business logic and appearance. It has become a key technology for developing strong online applications, allowing developers to design engaging and responsive user interfaces using the Java programming paradigm.

JSP lifecycle 

JSP has a multi-stage lifecycle that ensures dynamic web content production. Here’s a quick summary of the JSP lifecycle:

• Translation of JSP to Servlet: In the first phase, the.jsp file is translated to _jsp.java.
• Compilation of JSP pages: The translated Java Servlet file (_jsp.java) is compiled into a Servlet class file.
• Classloading: The built Servlet class is now loaded into the container using a class loader.
• Instantiation: During this stage, the web container creates an instance of the Servlet class.
• Initialization: The container calls the _jspinit() function. The _jspinit() function is called just once in a life cycle when the Servlet instance is generated.
• Request Processing: The container now invokes the _jspservice() function to handle the request. You cannot override this method.
• Destroy The _jspdestroy() function is used to remove the servlet instance from usage. The container uses the _jspDestroy() function to do any necessary cleanup. _jspdestroy() method can be invoked only once and can be overridden. 

Servlet lifecycle 

The Servlet life cycle consists of four separate steps that are all coordinated within a Servlet container context.

Stage 1: Loading and Instantiation

When a user makes an HTTP request for a certain URL, the first step is to load Servlets. The web server transmits this request to the Servlet container, which then maps and loads all necessary Servlets. This critical phase lays the framework for future exchanges.

Stage 2: Initialization (the init() method).

Following the loading stage, the Servlets are initialized. The container invokes the init() function, indicating that the Servlet instance is ready for service. Importantly, this function is only called on the first request, ensuring that the Servlet is fully configured before handling client interactions.

Step 3: Request Processing (service() Method)

The service() method is at the heart of the Servlet’s operation, as it processes client requests. When the Servlet receives a request, it calls this method to read the incoming data and provide a personalized response for the client. Notably, the Servlet remains within the container’s area, ready to handle new client requests, ensuring an efficient and responsive web service.

Stage 4: End (Destroy() Method)

As the final act in the life cycle, the container calls the destroy() function, bringing the Servlet instance to an end. The choice to invoke this method is container-specific, and it is only executed once during the Servlet’s life cycle. This function enables a gentle termination of the Servlet instance, allowing for cleanup tasks. The Servlet’s memory and related objects are then trash collected, which frees up resources.

Difference between Servlet and JSP

Servlets are a method to develop web applications by implementing them in a platform-independent and component-based approach. It does not abide by the performance-based restrictions of CGI programs (Common Gateway Interface). Servlets can access all the Java APIs and the JDBC API to access enterprise databases.

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JSPs are utilised for server-side programming and are also used to create platform-independent, dynamic web applications. If we want to have a clear view of JSP vs. Servlet, we can compare them on the following factors to help decide which one is a better choice if there is any specific requirement.

Servlet	JSP
Servlets are faster as compared to JSP, as they have a short response time.	JSP is slower than Servlets, as the first step in the JSP lifecycle is the conversion of JSP to Java code and then the compilation of the code.
Servlets are Java-based codes.	JSP are HTML-based codes.
Servlets are harder to code, as here, the HTML codes are written in Java.	JSPs are easier to code, as here Java is coded in HTML.
In an MVC architecture, Servlets act as the controllers.	In MVC architectures, the JSPs act as a view to present the output to the users.
The service() function can be overridden in Servlets.	The service() function cannot be overridden in JSPs.
The Servlets are capable of accepting all types of protocol requests.	The JSPs are confined to accept only the HTTP requests.
Modification in Servlets is a time-consuming and challenging task, as here, one will have to reload, recompile, and then restart the servers.	Modification is easy and faster in JSPs as we just need to refresh the pages.
Servlets require the users to enable the default sessions management explicitly, as Servlets do not provide default session management.	JSPs provide session management by default.
Servlets require us to implement the business logic and presentation logic in the same servlet file.	JSPs give us the flexibility to separate the business logic from the presentation logic using javaBeans.
Servlets can handle extensive data processing.	JSPs cannot handle data processing functions efficiently.
Servlets do not provide the facility of writing custom tags.	JSPs can provide the facility of building the JSP tags easily, which can directly call javaBeans.
In Servlets, we do not have implicit objects.	In JSPs, we have support for implicit objects.
Servlets are hosted and executed on Web Servers.	JSP is compiled in Java Servlets before their execution. After that, it has a similar lifecycle as Servlets.
We need to import all the packages at the top of the Servlets.	In JSPs, we can import packages anywhere in the file.
Source	Source

The Advantages of using Servlets

• Servlets load only one copy into the Java Virtual Machine. This makes their memory efficient and faster.
• The response time is significantly less, as it saves time to respond to the first request. 
• Servlets are easily accessible, as they use standard API that is used by a large number of web servers.
• It is easy for development and is platform-independent.
• Servlet’s usage doesn’t constrain the web servers. 
• Servlets help developers access a large number of APIs, which are available for Java. 
• It is very easy to maintain multiple Servlets for a single web application.
• Servlet containers provide developers with the facility of support to several other features like resource management, sessions, security, persistent, etc. 
• If servlets have multiple requests, the web containers provide threads to handle more than one request.

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The Advantages of using JSPs

• JSP can be used to write Servlets.
• JSP is very easy to modify, and therefore, it makes it very convenient.
• Developers can easily show and process information in JSP.
• JSP can use the multithreading feature of Java.
• JSP can be easily connected to the MYSQL databases. 
• JSP can use the exceptional handling feature of Java.
• JSP has better performance and scalability, as developers can embed dynamic elements into the HTML code.
• JSP is based in Java and is platform-independent.

As we have now discussed the advantages of using Servlets and JSPs, we will now take a look at the disadvantages of using both of them, when compared to each other. 

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Disadvantages of using Servlet

• Servlets create threads and not a process when a request arrives.
• It is harder to code and perform exception handling, as Servlet codes are not thread-safe by default.
• Java Runtime Environment is necessary to run Servlets on the server.
• Developing Servlets requires experience and a lot of knowledge of Java Servlets for development.
• Only one Servlet is loaded into the JVM.
• HTML code and Java code are interdependent and can cause errors if changes are not taken into consideration. 

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Disadvantages of using JSP

• It is very difficult for developers to perform database connectivity in JSP.
• As the JSP is compiled on the server, it is not memory and time-efficient.
• It is hard to track errors in JSP files because they are an extension to Servlets. The JSP codes are processed into Servlet codes for compilation.
• As JSP is an HTML file, it doesn’t provide many features. 

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Comparative analysis: Servlet vs JSP 

Now that we have covered what is JSP and Servlet in detail, let’s delve into a detailed comparative analysis. JSP Servlet in Java are essential components of Java’s web development stack, each serving a particular purpose while complementing one another. Let’s do a comparison study to determine their differences and strengths.

Roles and Purpose: JSP is primarily concerned with design, allowing developers to incorporate Java code directly into HTML pages using specific tags. It combines the power of Java with the simplicity of HTML to make it easier to create dynamic web pages. Servlets are Java classes that enhance the capabilities of a web server. They manage requests, process data, and create dynamic content. Servlets are more suited to handling complicated server-side logic and managing business activities.

Structure and Syntax: JSP servlet has a tag-based syntax, making it easier for developers who are familiar with HTML. JSP tags are used to incorporate Java code, and the container compiles the resulting page into a servlet during runtime. Servlets are written entirely in Java and take a procedural approach. They demand more explicit handling of HTML material, necessitating the use of HTML code within the Java class.

Ease of Development: Because of Java’s incorporation with HTML, it is often seen as more user-friendly, particularly for front-end developers. JSP streamlines the generation of dynamic content while reducing the need for substantial Java coding.  Servlets are appropriate for developers with solid Servlets and JSP experience. While servlets provide greater flexibility over application logic, they have a higher learning curve for people unfamiliar with Java.

Maintenance and Concerns: JSP aims to isolate business logic from display, resulting in better code structure. To guarantee readability and maintainability, a clear demarcation between Java code and HTML is required. Servlets Demand a more explicit separation of concerns, which is useful for large-scale systems with complex business logic. However, preserving clarity necessitates disciplined coding techniques.

Flexibility: JSP and Servlet have limited flexibility since they focus mostly on presentational issues. Servlet provides greater flexibility, making it suited for a variety of server-side activities, including managing complicated business processes.

Use Cases:  Project on JSP and Servlet thrives in cases that need HTML-centric development, making it suitable for content-heavy websites. Its tag-based framework enables seamless integration of Java code into HTML, making cooperation between designers and developers easier. Servlets and JSP, on the other hand, excel at activities that need complex business logic, competent request management, and server-side data processing. Their programmatic approach and versatility make them ideal for handling sophisticated server-side tasks in Java web development.

Importance of using JSP and Servlet

JSP is a server-side technology that allows you to write server-side code and develop web pages in a standard Java programming language. On the other hand, Servlet is a Java API (Application Programming Interface) that enables you to write server-side code and develop web applications in a standard Java programming language.

When you use JSP, you need to write server-side code because it is impossible to access the application’s client-side using only client-side code. When you use Servlet, you can access both the client and server sides of your application without having to write any server-side code. Because JSP is an HTML templating system, it is easy to extend and modify by writing JavaScript or other client-side scripting languages. This makes it suitable for creating dynamic web applications with complex business logic. On the other hand, Servlet is an API that provides functionality such as logging and session tracking. It is suitable for implementing simple user interfaces or front ends for your business logic with limited complexity. JSP is generally more suitable for complex business logic and rapid development. In contrast, Servlet is more suitable for simple UI development, or front ends for your business logic with limited complexity.

Javatpoint – a resource to get your basics in order

Javatpoint provides an array of free tutorials and courses which are good for beginners to understand JSP, servlet, and the important nitty-gritty of servlets and JSP. The platform is designed in a way to give you a push towards your journey. However, you should keep in mind that mastering JSP servlet will come with practicing and going into the depths of things. To get better at JSP servlet, you will need to go beyond just the basics. That said, javatpoint is indeed a good starting point if you are completely clueless or need some basics covered before you get into the intense parts. However, only after working on real-world problems and trying to figure out solutions on your own will you come to experientially understand the practical difference between JSP and servlet Javatpoint, and the advantages of JSP over servlet, along with other relevant things about servlet and JSP. 

Why is JSP better than Servlet? 

The decision to employ Java JSP and Servlet is based on the online application’s unique requirements and characteristics. Both JSP and Servlet are essential components of Java’s web development armory, and their merits apply to various parts of web application design.

JSP

HTML-Centric Views: The Java JSP example is particularly useful for building HTML-centric views. Developers may embed Java code into HTML, making it easier to create dynamic content while keeping presentation and logic separate.

Simplifying Front-End Development: If your team comprises both web designers and developers, JSP may be a good alternative. Its tag-based syntax makes it more accessible to designers, allowing cooperation without having a deep grasp of Java.

Rapid UI Development: The JSP servlet tutorial is ideal for quickly creating user interfaces, particularly in circumstances where dynamic material must be smoothly merged with static HTML.

Servlet

Robust Business Logic: One of the advantages of Servlet excel at managing sophisticated business logic on the server side. If your application requires extensive processing, data manipulation, or complex algorithms, Servlets offers a reliable development approach.

Fine-Grained Control: Servlets provide precise control over the HTTP request and response cycle. This degree of control is useful when you need to personalize and optimize the handling of requests at the lowest level.

Handling Different Types of Requests: In addition to displaying HTML, servlets can handle various requests. They are capable of processing and responding to many forms of data, making them appropriate for a wide range of web application scenarios.

Conclusion

In this article, we have had a detailed review of both Servlets and JSPs, and also looked at the major differences between JSP and Servlet. In conclusion, we can say that Servlets are server-side programs and take care of the processing, whereas JSP is an interface that is built on top of Servlets to provide added functionalities. Because the JSP acts as an interface, developers can easily manage and integrate the UI part of the applications in JSP files.

JSP provides added flexibility compared to the Servlet, as JSP contains custom tags for building reusable codes. Servers are not beneficial for session management, as they are not enabled by default, whereas JSP makes session management and tracking due to its property of handling multiple requests on a single thread. 

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