Java Server Pages (JSP) Presented by: Ananth Prasad & Alex Ivanov May 10, 2001
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Java Server Pages (JSP)
Presented by:
Ananth Prasad & Alex Ivanov
May 10, 2001
JSP Definition
JSP is a dynamic scripting capability for web JSP is a dynamic scripting capability for web pages that allows java as well as a few pages that allows java as well as a few
special tags to be embedded into a web file special tags to be embedded into a web file (HTML/XML, etc). The suffix traditionally (HTML/XML, etc). The suffix traditionally ends with .Jsp to indicate to the web server ends with .Jsp to indicate to the web server
that the file is a JSP file. JSP is a that the file is a JSP file. JSP is a server sideserver side technologytechnology - can't do any client side - can't do any client side
validation with itvalidation with it
JSP
JSP
• A JSP file is a script like an ASP file except that represents a template for a web page.
• When the page is first requested, the JSP is compiled into a “servlet” form and executed.
• Afterwards the JSP script exists as a compiled java byte-code (unless it is changed)
Why not just write Servlets?
The focus is on HTML. Java and the JSP The focus is on HTML. Java and the JSP extensions assist in making the HTML moreextensions assist in making the HTML morefunctional. Servlets on the other hand allow functional. Servlets on the other hand allow outputting of HTML but it is a tediousoutputting of HTML but it is a tediousprocess. process.
It is easy to make a change and then let the JSP It is easy to make a change and then let the JSP capability of the Web Server you arecapability of the Web Server you areusing deal with compiling it into a Servlet and using deal with compiling it into a Servlet and running it. running it.
JSP
JSP BenefitsEasy and Rapid Web Development, Easy and Rapid Web Development,
Deployment and MaintenanceDeployment and Maintenance
Emphasizing Reusable ComponentsEmphasizing Reusable Components
Separating Content Generation from Separating Content Generation from PresentationPresentation
JSP Benefits Contd.....
Open Development and Widespread Open Development and Widespread Industry SupportIndustry Support
Platform IndependencePlatform Independence
Simplifying Page Development with Simplifying Page Development with TagsTags
Use of Beans
One use of JavaBeans is as a data encapsulator. A property of a JavaBean is simply the data (state) of the bean. Properties are accessible by two methods: the getter and the setter. The value of the property is accessed by the getter method. If the property is writeable, its value is changed by the setter method.
Use of Beans contd.....
Loading a Bean - <jsp:usebean>
Initializing a Bean - <jsp:setProperty>
Displaying Dynamic Content - <jsp:getProperty>
Java code in your page?
Three ways…
• Using declarations, <%!.........%>.
• With scriptlets, <%...........%>.
• Expressions between <%=.....%>.
A look at simple JSP code
<html>
<body>
<b>I’m HTML code.</b><br>
<% out.println(“I’m Java code.”) %>
</body>
</html>
Example, “Hello, World”
Example:<%
String name = null; if (request.getParameter(“name”) == null ) { %> Hello, World<% } else {
println.out(“Hello,” + name); } %>
JSP Vs JavaScript
JavaScript– Validates on Client Side– Less Secure– Browser Dependent– Unstable– ….
JSP Vs. Servlets
Similarities
• Provide identical results to the end user
• JSP is an additional module to the servlet
JSP Vs Servlets contd.....
Differences
• Servlets: “HTML in Java Code”HTML code inaccessible to Graphics designer
But accessible to Programmer
• JSP: “Java Code Scriplets in HTML”HTML code accessible to Graphic Designer
Java code accessible to Programmer
JSP Vs ASP
ASP JSPWeb Server IIS, PWS AnyPlatforms Windows AnyReusable crossplatformcomponents?
No Yes
Security againstSystem Checks
No Yes
CustomizableTags
No Yes
Useful Links of JSP
• The current version of JSP is 1.1. It is available from
http://java.sun.com/products/jsp.
• Archives of the JSP mailing list are available at
http://archives.java.sun.com/archives/jsp-interest.html
• web application servers support JSP
http://www.flashline.com/components/appservermatrix.jsp
• JSP Demo website
http://www.flashline.com/
Conclusion
• JSP is robust server side dynamic web page generator.
• Easy to implement
• Easy to manage
• Code is portable
• Free
References
• Web page development using JSPby Duane K. Fields, Mark A. Kolb
• Java Server Pages -- by Hans Bergsten
• Core Servlets and JSP -- by Marty Hall
• Graphics used on this presentation was obtained from different web sites.
The End
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