CIS 550CSE 330 Project tutorial

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CIS 550/CSE 330 Project tutorial

• Fall 2008

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Project Motivation

• Web 2.0 sites and tools
• Facebook, Digg, Blogspot, Flickr,

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Project News sharing

• Allow users to share popular worldwide news at
  any moment.
• Basic unit of news a hyperlink, pointing to
  an article, story, image or video.
• Allow users to vote, comment and discuss on
  potential topics.

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Basic functionality requirements

• Registered User Base
• Hyperlink lists
• Friend lists
• Voting, comments
• Keyword search
• XML feeds
• Crawler
• Recommendation system
• Basic GUI, at the least!

Additional features are welcome and encouraged,
possibly for extra credit!
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Languages

• With TA tech support
• Java (strongly recommended)
• Without TA tech support
• Python
• C, C
• .NET

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Languages (contd)

• Other frameworks Ruby on rails, Django, PHP
• -- No object-relational mapping will be allowed.
• -- You must write SQL queries and definition
  statements and XML generating code on your own!
• For any other language, please talk to
  profs/TAs.

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Some equipment youll need

• IDE Eclipse, NetBeans
• DBMS Oracle, MySQL
• Servlet containers Tomcat or Jetty
• Recommended tools
• Version Control Subversion
• Presentation JSP, Struts

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Tutorial on Java Servlets

• Better alternative to CGI
• Main difference multiple processes vs. multiple
  threads
• Basic architecture

Servlet container
REQ
DBMS
Servlet
Browser
RESP
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Servlet containers

• Servlet containers act as a web server plus an
  execution environment for java code.
• Examples Apache Tomcat and Jetty
• Tomcat on SEAS documentation to be provided.
• Test on your own machine first!

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Jetty

• A simple servlet container and web server written
  in Java.
• To start java jar start.jar
• Web applications go in the webapps directory.
• webapps/hello maps to http//localhost8080/hello
• Jetty listens on port 8080 by default.

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Forms

• Forms allow the user to submit data to the
  servlet

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The Servlet API

• Two required functions for handling requests
• public void doGet(HttpServletRequest req,
• HttpServletResponse resp)
• public void doPost(HttpServletRequest req,
• HttpServletResponse resp)
• Req contains information about the client and the
  request.
• Resp gives you access to the output stream.
• http//java.sun.com/products/servlet/2.3/javadoc/

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Compiling a Servlet

• Servlet class files go in WEB-INF/classes.
• Servlet API classes are provided by Jetty
• JETTY_ROOT/lib/servlet-api-2.5-6.1.11.jar
• To compile
• javac -cp JETTY_ROOT/lib/servlet-api-2.5-6.1.11.j
  ar.
• HelloServlet.java
• For Oracle, we also need ojdbc14.jar in the
  libraries directory and the classpath.

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web.xml

• Defines the mapping between URLs and the servlet
  class that handles requests.
• Example
• HelloServlet
• HelloServlet
• HelloServlet
• /servlet

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Java Server Pages (JSP)

• Allow embedding Java in HTML.
• Good for defining data presentation.
• Struts (not shown here) is a framework for
  combining servlets and JSP pages.
• Application logic handled by Servlet.
• Presentation generated by JSP.

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Managing Sessions

• HttpSession object provided by the servlet
  container.
• Associates arbitrary data with the user session.
• Managed internally with cookies.
• req.getSession() or req.getSession(boolean)

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Questions?