CSE 308Software Engineering

World Wide Web Apps

Why do some apps succeed? A good idea

solves customer pain the easy part

Commitment time & energy the hard part

A great team the harder part

Did someone say teams? Round 2

LFM

LFG

How will we place software engineers?

The 6 LFM Groups will:

1. Interview the candidates

2. Discuss hiring preferences

3. Email me their hiring preferences ranked 1-3

When?

– at the end of class

Then what?

– I'll notify teams of assignments

We (i.e. the CS Faculty) want: polished work visible projects positive team experiences inspired presentations

Your Group Projects I'll provide a Request for Proposal

(RFP)

You'll write & submit your Proposal

Your Proposal should be for a Web App

What's an RFP again? A document Describes a problem Offers grants/funding Solicits Proposals Best Proposal(s) get funded

What's a Proposal? A document

describes team's accomplishments & assets

describes approach to solving problem describes how funds will be used selects PI

NSF Grant Proposal Guide:http://www.nsf.gov/publications/pub_summ.jsp?ods_key=gpg

Industry vs. Academia Successful Project

In Industry

-earns company $

-earns investors $

-pays employees

-market visibility

-significant market share

-grows

-hasn't filed for bankruptcy

-exit strategy?

Successful Project

In Academia

-earns University $

-earns inventor $

-pays research assistants

-is published in journal

-is patented/sold

-launches new company

-launches new industry

-hasn't been canceled

So why a Web app? Academia to Industry

i.e. good experience

Visibility i.e. more potential users:

to test to provide feedback to use

Web users have high expectations

Want apps that are: fast elegant user friendly dynamic mobile secure social cross-platform solve customer pain

A brief history of the Internet1960sAT&T

Modem

1969ARPANET Launched

1970sTCP/IP

Proposed

1980sTCP/IPFully

Adopted

1970sEmail

Invented

1980sWWW

Proposed

1990sWWWOnline

1990sMosaic

Invented

1970sCompuserv

eISP

Launch

1990sSearch Engine

Invented

1990sJavaScriptInvented

2000sGlobalizedConnectio

ns &Innovation

s

2000sMobile

Everything

2000sSocial

Everything

2000sThe

Computer Utility?

The Web from 10,000 feet An amalgamation of tech

Held together by standards

WWW, URL, URI, HTML, XHTML, XML, HTTP, HTTPS, TCP, IP, UDP, FTP, MIME, IMAP, DNS, JavaScript, CDN, ICANN, IANA, RSA, ICMP, LAN, WAN, POP3, WEP, WPA, LARP, LAIRE

Web tech overview Front end

Gets user input, renders, talks to server HTML, JavaScript, JavaScript libraries, plug-ins,

etc.

Back end Talks to client, performs business logic, talks to

DB Java, PHP, C#, etc.

Databases Store permanent data MySQL, Oracle, JavaDB, etc.

WWW Tech Generations Early 1990s

1St – Flat HTML files, images, etc.

Mid 1990s

2nd – CGI, Perl, etc.

Late 1990s

3rd – Application Servers, Java, C#, etc.

Late 2000s

4th – The Cloud, CDNs GAE, AWS, etc.

What is JavaEE?

• Java Enterprise Edition

• Tools & APIs for eCommerce

• Good News & Bad News

JavaEE Setup is much of the battle

A brief history of JavaEE

1stGeneration – Servlets

2nd Generation – Java Server Pages

3rd Generation – Java Server Faces

What is a Java Web Application?

• Runs on an application server– i.e. Glassfish, Tomcat, WebSphere

• Generates interactive Web pages with:– markup code (i.e. XML, HTML)– dynamic code (i.e. JavaScript)

• Look at WebJotto example app

What's a Web Form? HTML component Specify submit actions

– route to action URL/method (i.e. servlet)

Ex:

What's a raw servlet? A Java Program Sits on a Java App Server Starts upon first request You may register listeners to respond to:

– initialization, requests, destruction, etc. Servlet responds via doGet or doPost

public class MyServlet extends HttpServlet{

public void doGet(...

Oversimplified Servlet Architecture

HTML PAGE

Web Form

Browser JavaEE ServerHttpServlet

doGet(...

request

HTML PAGE

response

doGet(HttpServletRequest req, HttpServletResponse resp)

req

has info about request

use to get form data

public void doPost(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

String firstName = req.getParameter("firstname");String lastName = req.getParameter("lastname");String email = req.getParameter("email");… NOW DO SOMETHING WITH THIS INFOresp.setContentType("text/html");PrintWriter out = resp.getWriter();out.println("<html>......

resp

has output stream

use to build response

JSPs Features:

HTML templating (i.e. pre-built partial pages) custom tags scriptlets (i.e. code mixed inside JSP)

bad idea

JavaEE 5 Use discouraged in JavaEE 6/7 Replaced by JSF/Facelets Still lots of servers out there using

them

Poor form: JSPs with scriptlets

Better form: JSPs with JSTL

JSFs Uses:

All templating More & better Tag Libraries EL Ajax Facelet-JavaBeans mappings

changes to mapped bean variables auto refresh on client

JSPs & JSFs: processed on server to build page at time of

request

Better form: JSPs with JSTL

Developing Backwards What's that?

Find the deployment platform first

May not use the greatest and latest

Find your app a home before starting

Our home?

– Appspot.com (more on this later)