What is the Difference Between JSP and Servlet? with Proper Definition and Brief Explanation

The main difference between JSP and Servlet is that the JSP is a web page scripting language that can generate dynamic web content while the servlet is a Java program that is already compiled and used to create dynamic web content.

In a typical web application, the client requests a web page from the server, and the server responds with the requested page. These pages can be static or dynamic. The content of a static page is already created. The content of a dynamic page is created at run time. JSP and Servlet are two methods in Java to create dynamic web pages. JSP is translated and compiled into a servlet by the web container. On the other hand, a servlet is a Java program that is managed by the web container.

Key Areas Covered

1. What is JSP?
     – Definition, Functionality
2. What is servlet?
     – Definition, Functionality
3. What is the relationship between JSP and Servlet?
     – Association scheme
4. What is the difference between JSP and Servlet?
     – Key differences comparison

Key terms

Java, JSP, Servlet, Servlet Tag, Servlet Mapping Tag

What is JSP?

JSP stands for Java Server Pages . They have the .jsp file extension. It is used to create dynamic web pages. Programmers can insert java code into HTML pages by placing the code inside special JSP tags that start with <% and ends with %>. There are multiple JSP tags for various purposes, such as getting data from a database, passing control between pages, sharing information between requests and pages.

                                                              Figure 1: Life of a JSP file

A JSP file consists of Java and HTML/XHTML/XML code. It is built on Java Servlets. Many JSP pages can be combined with servlets to handle business logic. JSP has access to several powerful Enterprise Java APIs like JDBC, EJB, JNDI etc. It is possible to collect user information through web page forms and submit database records and create web pages dynamically using JSP.

what is servlets?

Servlet is used to create dynamic web pages. Suppose the client requested a dynamic web page named abc.html. The server doesn’t have it, and the request goes to a helper application called a web container. It can be Apache Tomcat, Glassfish, etc. In the web container, there is a special file called the deployment descriptor (web.xml). Map each request to a corresponding servlet. So it knows which servlet should be called for the incoming request.

A servlet is a java file that can take a request from the client, process it, and provide an HTML file as a response. There are multiple servlets inside the web container. It is also possible to assign multiple requests to a servlet. Therefore, all these settings are included in this special file which is the web.xml file.

The web.xml has two tags: servlet tag and servlet mapping tag. The servlet tag is used to mention the class name while the servlet mapping tag is used to mention the URL pattern. Annotations help to do this mapping. To create a servlet, the programmer must create a class and extend the HTTP servlet. Servlet accepts the request, processes it and sends it to the client in HTML format. Also, a dynamic page is sent to the client as a response.

Relationship between JSP and Servlet

• JSP is translated and compiled into a servlet.

Key Differences

Definition

JSP is a web scripting language that helps developers create dynamic web pages based on HTML, XML, or other types of documents. Servlet is a server-side Java program module that processes and responds to client requests by implementing the servlet interface. The definition itself explains the basic difference between them.

Main Focus

Another difference between them is that JSP focuses more on displaying information while servlet mainly focuses on information processing.

Execution Speed

Also, the JSP runs slower compared to a servlet and is compiled into a servlet. On the other hand, the servlet runs faster than JSP.

Model View Controller (MVC)

Another difference between them is that in MVC architecture, JSP works as the view while servlet works as the controller.

Complexity

Also, JSP programming is easier compared to a servlet.

Consists in

The JSP file consists of Java, HTML, XHTML, or XML. Servlet is fully functional Java code.

Applicable Scenario

Also, we can see a difference between JSP and application based servlet as well. While the JSP is useful for displaying report details, the servlet is useful for processing a submitted form.

Conclusion

The difference between them is that JSP is a web page scripting language that can generate dynamic web content while servlet is a Java program that is already compiled and used to create dynamic web content. In short, JSP is more preferred when there is not much involved in data processing while servlet is more suitable when it requires more data processing.

Reference:

1. Introduction to Servlets | Graphic Representation, Telusko, February 2, 2017, Available here.
2. “JSP Overview.” Www.tutorialspoint.com, Tutorials Point, available here.

Courtesy image:

1. “JSPLife” By User:Zedlander, User:Sae1962 – (CC BY-SA 3.0) via Commons Wikimedia

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