Java is among the most used and famous programming languages throughout the globe. Java is an object-oriented language used widely to create applications and software. You can create mobile apps, web apps, games, etc., using java. Java supports many modules and frameworks in it. 2 most commonly used java frameworks are JSP and Servlet. You can read this article anytime if you want to learn about JSP and servlet. In this article, you will learn about how JSP and Servlet work and how they differ from each other.
What is JSP?
JSP stands for Java Server Pages. It is a collection of different technologies which let us create webpages using java. A JSP tag is created, which inserts Java code into the HTML pages. JSP is widely used to build web-based apps. JSP is very easy to code and simple to understand. The data in JSP is of 2 types:
Dynamic data
All the data that varies from user to user and is generated during the runtime is known as Dynamic. JSP elements and tags are used to generate dynamic data
Static data
The data similar to all the users and cannot be changed is known as Static. Static data supports XML, HTML, WML and SVG formats.
What is Servlet?
A servlet is a Java programming class. It is used to develop and build servers for applications. To use the functionalities of servlet one must need to extend the servlet class. Servlet class follows a certain life cycle:
- Firstly the servlet class is loaded.
- An Instance is created
- The init() method is invoked automatically.
- Service() method is invoked.
- Destroy()
Servlet offers fast development as compared to JSP. They are portable and are easy to handle.
Comparison of JSP vs Servlet
| Servlet | JSP |
| Servlet is a java class. One must extend a class with servlet to use its functionalities | JSP is actually a HTML code written in Java. |
| Servlet is easy to implement | JSP is not as easy as servlet |
| Servlet is faster in execution as compared to JSP | The JSP code is first translated to the java, thus making it slower to execute. |
| Service() method can be overridden. | Service() method cannot be overridden. |
| All kind of protocols are handled by Servlet. | Only HTTP requests are handled by JSP |
| In servlet you cannot write javascript at the client side. | Javascript at the client side is possible but requires verification. |
| Writing a code in servlet is difficult as compared to JSP | Since we have to write HTML codes in JSP, it is easier compared to servlet. |
Advantages and Disadvantages of using JSP
Advantages are:
- Modification in HTML code is very easy and convenient
- Multithreading is possible
- It lets us to separate the presentation layer from business logic.
- It is very scalable and faster in execution
Disadvantages are:
- Connectivity with databases is not easy
- We get HTML screen as an output which is not enough feature rich.
- JSP take more time to compile because of the translation into servlet.
Advantages and Disadvantages of using Servlet
Advantages are:
- You get to access a large set of API available.
- They provide rapid development and easy interaction among two or more servlet.
- Servlet works smoothly with all web browsers.
Disadvantages are:
- Servlet can make the application slow.
- A lot of dependence on HTML. Thus changes can be easily made by mistake.
- Multithreading is not safe thus use of exceptional handling is required everytime.
Working and Life Cycle of JSP and Servlet
JSP is actually a very fast way to create dynamic web pages. JSP’s life cycle includes its creation, conversion to servlet and then it follows the same cycle as of a servlet. It continues to follow the servlet cycle until destroy() is called.
The life cycle of JSP is:
- First step is of translating a JSP page to servlet
- JSP page is then compiled to java
- Class is loaded and instantiation occurs.
- init() method is called
- _jspservice() method is called for processing requests
- destroy() method ends the execution
Servlet is managed by servlet engine. It works on the model of request and response to the user. Life cycle of servlet is very simple and straightforward:
- Execution of servlet begins
- init() method is invoked as soon as the execution begins. This method is called only once.
- Then comes the service() method. It is used to handle the requests and can be called any number of time.
- Response is given to all the requests.
- Destroy() method is called to end the execution.
Conclusion
JSP and servlets are both widely used for creating web-based applications in java. The way java is platform independent, they are the same too. It is necessary to know the difference between JSP and Servlet are both used in web app development. JSP works on web pages, and servlets work on creating web servers. In this article, I have tried to cover everything necessary to learn about JSP vs Servlet. We Hope, this article has covered all your doubts about them.