Java Server Pages (JSP) Presented by: Ananth Prasad & Alex Ivanov May 10, 2001.

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

• 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 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

Java Server Pages (JSP) Presented by: Ananth Prasad & Alex Ivanov May 10, 2001.

Documents

Transcript of Java Server Pages (JSP) Presented by: Ananth Prasad & Alex Ivanov May 10, 2001.