An Introduction to JavaServer™ Pages Prepared by Nicole Swan

General JSP Information Most Common JSP Components –Static HTML/XML components –Special JSP tags –Optionally, snippets of code written in Java called “scriptlets” JSPs are parsed on the server side –Translation phase occurs only once unless JSP is updated –Compiled class is then served to each client upon request

Advantages of JSP Separation of static from dynamic content Write once run anywhere Dynamic content can be served in a variety of formats Recommended web access layer for n-tier architecture Completely leverages the Servlet API (Source: )

JSP vs. ASP (Source: ) JSPASP Web Server Support Most popular web servers including Apache, Netscape, Microsoft IIS. Native support only within Microsoft IIS or Personal Web Server. Platform Support Platform independent. Runs on all Java-enabled platforms. Is fully supported under Windows. Component Model Reusable, cross-platform components like JavaBeans, EJB, and custom tag libraries. Uses the Win32-based COM component model. ScriptingJava or JavaScript. Supports VBScript and JScript for scripting. SecurityJava security model. Windows NT security architecture. Database AccessJDBC Active Data Objects Customizable Tags Extensible with custom tag libraries. Not extensible and cannot use custom tag libraries.

Basic JSP Syntax Directives Declarations Expressions Comments Scriptlets

Directives page directives are found at the top of most JSP pages. Specify java packages to include, the page language type, or the content type. Examples

Directives include directives are used to include static html content or other JSP content. Example

Declarations Declarations are found within the tag. Anything within this tag must be valid Java code including all appropriate syntax. Example <%! public void foo(){ out.println( i ); } %>

Expressions With expressions, the result of evaluating the expression is directly included in the output of the JSP page. Examples

Comments JSP comments are enclosed in the tag. Any comments in this format are not viewable when viewing the page’s source in a browser. Example Note: Can still use HTML comments though they are viewable to client

Scriptlets Scriptlets are used to embed code fragments within a JSP page. The tag is used. Example ”>

JSP Tag Libraries Allow Java developers to decouple static HTML and complex server-side behaviors In a sense, are a replacement for scriptlets Required use by many companies in JSP development Example true Condition was true Condition was false

JavaBeans JavaBeans topic is broad and complex For our purposes, allow JSP developers to decouple static HTML and complex server- side behaviors through the use of classes

JSP Development Environments Forte for Java (Community or Enterprise edition) –Provides syntax coloring which is nice Notepad –Simple and readily available WYSIWYG environments –Macromedia DreamWeaver –Adobe GoLive Macromedia ColdFusion Studio

Web Servers/Servlet Containers Apache Tomcat (Open Source) – Jetty (Open Source) – Bajie (free) – –Created by student at University of Texas – Dallas Various third-party servlet containers for various web servers –

Tomcat Servlet Container Can run as standalone web server Can serve static HTML as well as dynamic JSP content

Installing and Running Tomcat Download from tomcat-4.0/release/v4.1.18/bin/ tomcat-4.0/release/v4.1.18/bin/ Using WinZip (or some other similar tool) extract contents to C:\ (or wherever you choose) Set environmental variables (see handout) Start it up! (see handout) Check to see that it was installed properly (see handout)

Additional JSP Resources JSP Tutorial – Java Developer Connection – JavaServer™ Pages – JSP Syntax Reference – Google

Questions & Comments?