Web Component Development Using Servlet & JSP Technologies (EE6) - Chapter 2 - Introduction to Java Server Pages
Introduction It stands for Java Server Pages. It is a server side technology. It is used for creating web application. It is used to create dynamic web content. In this JSP tags are used to insert JAVA code into HTML pages. It is an advanced version of Servlet Technology. It is a Web based technology helps us to create dynamic and platform independent web pages. In this, Java code can be inserted in HTML/ XML pages or both. JSP is first converted into servlet by JSP container before processing the client’s request. JSP pages are more advantageous than Servlet: They are easy to maintain. No recompilation or redeployment is required. JSP has access to entire API of JAVA . JSP are extended version of Servlet. Features of JSP Coding in JSP is easy :- As it is just adding JAVA code to HTML/XML. Reduction in the length of Code :- In JSP we use action tags, custom tags etc. Connection to Database is easier :-It is easier to connect website to database and allows to read or write data easily to the database. Make Interactive websites :- In this we can create dynamic web pages which helps user to interact in real time environment. Portable, Powerful, flexible and easy to maintain :- as these are browser and server independent. No Redeployment and No Re-Compilation :- It is dynamic, secure and platform independent so no need to re-compilation. Extension to Servlet :- as it has all features of servlets, implicit objects and custom tags
More Related Content
What's hot (18)
Similar to Web Component Development Using Servlet & JSP Technologies (EE6) - Chapter 2 - Introduction to Java Server Pages (20)
More from WebStackAcademy (20)
Recently uploaded (20)
Web Component Development Using Servlet & JSP Technologies (EE6) - Chapter 2 - Introduction to Java Server Pages
- 1. Web Component Development Using Servlet & JSP Technology (EE6) Module-2: Introduction t PaP)
- 2. www.webstackacademy.com Introduction to Java Server Pages(JSP)
- 3. www.webstackacademy.com Objectives Upon completion of this module, you should be able to: ● Describe a significant weakness in servlets when used alone. ● Write a simple Java Server Page (JSP) ● Describe the translation of a JSP into a servlet ● Understand the basic goals of MVC
- 4. www.webstackacademy.com Relevance Discussion – The following questions are relevant to understanding how to develop a view component: ● How easy would it be to edit HTML that is created by a Java program? ● What would make a good separation of concerns for a web application?
- 5. www.webstackacademy.com A Weakness in Servlets ● Most modern web applications have elegant and complex user interface designs. The designs are often created by dedicated web designers, and even if that is not the case, the HTML pages that implement the designs are frequently created using “What You See Is What You Get” (WYSIWYG) Graphical User Interface (GUI) based design tools. Such design tools work on HTML, not on HTML embedded in Java program code. ● Because of this, the pure servlet approach becomes unmanageable—often catastrophically—when maintenance is required on the web pages. Having to re-type all the HTML code back into out.print(...) statements would be a very time consuming and error prone process.
- 6. www.webstackacademy.com Addressing the Problem With JSPs Soon after the original introduction of servlets, Java Server Pages, usually called simply JSPs, were introduced to address this problem. While a servlet is a Java source file containing embedded HTML, a JSP might be considered to be an HTML file with Java embedded in it.
- 7. www.webstackacademy.com Example of a very simple JSP. <%-- Simple Hello World JSP example --%> <%@page contentType="text/html" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <body> <% out.print("welcome to jsp"); %> </body> </html>
- 8. www.webstackacademy.com Key Elements of JSPs Within <% ... %> pairs, three distinct variations are exemplified. These are: ● Comments ● A “page directive” ● An “expression”
- 9. www.webstackacademy.com How a JSP Is Processed Before a JSP is executed for the first time, it is converted to an equivalent Servlet.
- 10. www.webstackacademy.com Reading Input Parameters From the Browser <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSP Page</title> </head> <body> <h1>Hello <%= request.getParameter("customerName") %> </h1> </body> </html>
- 11. www.webstackacademy.com Sending Parameters in an HTTP GET Request http://localhost:8080/SL314m2ex2/index.jsp? customerName=Corporal+Jones Note that the space is encoded as a plus sign (+). Other encodings are required for many other symbols, but such conversions are beyond the scope of this module.
- 12. www.webstackacademy.com Remaining Problems With the JSP Approach ● The JSP approach results in Java code embedded in an HTML source file. Because of this,programmers and web-designers must share the same file, and changes made by one group might cause bugs in the work of the other group. ● In fact, the root of the problem is that one of the basic tenets of good software design has been broken. That tenet states that unrelated concerns should be separated in the source code.
- 13. Web Stack Academy (P) Ltd #83, Farah Towers, 1st floor,MG Road, Bangalore – 560001 M: +91-80-4128 9576 T: +91-98862 69112 E: [email protected] www.webstackacademy.com