Java Web & JDBC Programming Introduction

Java Web & JDBC Programming by qrtt1, 2012.8

about me work for Muzee Co. lang: Java, c, python
RD MIS (Server Admin) Performance Tuning

Write a Simple Web App TODO List user login todo
list todo new todo modify todo delete todo

Source Code About this tutorial web server and handler https:/
/github.com/qrtt1/tut_web pure jdbc lab https:/ /github.com/qrtt1/tut.TodoJdbc jdbc + dbcp + dbutils https:/ /github.com/qrtt1/tut.TodoDao todo web in model 1 https:/ /github.com/qrtt1/tut.TodoJspWeb todo web in model 2 https:/ /github.com/qrtt1/tut.TodoModel2Web

Needs Skills Use the Database System JDBC Programming Web App
Programming View Presentation: JSP Business logic: Servlet & related APIs

Development Environment Tomcat 7 (Servlet/JSP Container) Support Servlet 2.x/3.x MySQL
& Connector/J Eclipse for JavaEE

Tomcat 7.x Servlet & JSP Container

MySQL settings set UTF-8 as default encoding set INNODB as
default engine (if ver < 5.5) enable innodb_ﬁle_per_table

Eclipse Settings Preference Workspace Text File Encoding: UTF-8 Web JSP
Files Encoding:

JDBC Overview Prepare Database (we use MySQL today) Understand JDBC
API Driver Common Usage Use Connection Pool Leverage JDBC helper library

Prepare MySQL Using MySQL Shell Manage User create account =
id + host grant privileges Manage Storage create database create tables Do Query CRUD

pure JDBC programming Load JDBC Driver Class.forName(...) Prepare JDBC URL
jdbc:mysql:/ /... Get Connection from DriverManager With URL Do Query With Connection Object PreparedStatement, Statement executeQuery, executeUpdate

Lab JDBC Database: todo_web table: users table: todos Query ﬁnd
a user by email Update the content of a todo

DAO & JDBC Helper Common DBCP Common DBUtils Mapping POJO
and the row of a table

Lab JDBC Helper & DAO Use Connection Pool set up
validate string DBUtils use QueryRunner and ResultSetHandler Work with Object {User, Todo} access by DAO {UserDao, TodoDao}

JDBC Programming QA Next Web Programming

Web App Programming Without Servlet/JSP Using Servlet/JSP Web Framework

browser web server Get ME URL It’s the content of
your URL Browsing

browser web server HTTP REQUEST HTTP RESPONSE HTTP Protocol

browser web server HTTP REQUEST HTTP RESPONSE Let’s Speak In
HTTP GET /index.html HTTP/1.0\r\n Host: www.google.com\r\n \r\n HTTP 200 OK\r\n Content-Length: 16384\r\n Content-Type: text/html; charset=utf-8\r\n \r\n <html>......

socket client socket server Socket Programming GET /index.html HTTP/1.0\r\n Host:
www.google.com\r\n \r\n (“ ”) .getBytes() client.getOutputStream().write ( ) HTTP 200 OK\r\n Content-Length: 16384\r\n Content-Type: text/html; charset=utf-8\r\n \r\n <html>...... client.getOutputStream() .write ( ) (“ ”) .getBytes()

browser web server HTTP REQUEST HTTP RESPONSE Dynamic Content CGI
(Common Gateway Interface) GET /index.html HTTP/1.0\r\n Host: www.google.com\r\n \r\n Static Resource Handler

web server HTTP REQUEST HTTP RESPONSE Common Gateway Interface CGI
Handler Static Resource Handler URI Dispatcher /icon/funny.png /index.html /cgi-bin/weather.pl /cgi-bin/stocks.pl

HTTP REQUEST How does CGI work ? CGI Handler web
server parsing HTTP Request to ENVIRONMENT variable redirect HTTP Request body to STDIN dispatch depends on URI CGI Application #!/usr/bin/perl print "Content-type:text/html\r\n\r\n"; print '<html>'; print '<head>'; print '<title>Hello Word - First CGI Program</title>'; print '</head>'; print '<body>'; print '<h2>Hello Word! This is my first CGI program</h2>'; print '</body>'; print '</html>'; 1; HTTP RESPONSE Generate HTTP Response to STDOUT CGI is a language-free-method

HTTP REQUEST How does Others work ? Others Handler web
server parsing HTTP Request to XXX language variable (deﬁned like CGI does) redirect HTTP Request body to STDIN dispatch depends on URI Other Server Side Programming Language def simple_app(environ, start_response): """Simplest possible application object""" status = '200 OK' response_headers = [('Content-type','text/plain')] start_response(status, response_headers) return ['Hello world!\n'] HTTP RESPONSE Generate HTTP Response by OUTPUT method (In this case, it is a callable object start_response and return the content)

HTTP REQUEST How does Java Servlet work ? Servlet Contiainer
web server parsing HTTP Request to HttpServletRequest object dispatch depends on Servlet URI mapping (deﬁned in web.xml, also in annotation after servlet 3.0) Java Servlet public class HelloServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.getWriter().write("<html><body>"); resp.getWriter().write("Hello Servlet"); resp.getWriter().write("</body></html>"); } } HTTP RESPONSE Generate HTTP Response by HttpServletResponse object

Demo Write Java Web App the hard way ӚϞ Java
Web Tech. ʘۃd༈νО͜ Java ྼ Ъ Web Application ճk Let’s reinvent the wheel

Web Programming QA Next Java Web Programming

Web Programming In Java Web Application Servlet Filter Listener JSP
Server-Side Resource. Ex. Database

Lab First Web App: Hello Servlet Implements a Servlet extends
HttpServlet resp.getWriter().println(...) Set Up Deployment Descriptor WEB-INF/web.xml

Servlet Features HttpServlet for business logic Filter usually for decorating
or apply changes to HttpServletRequest or HttpServletResponse Listener & Events usually for initializing and cleaning up resources.

Filter A ﬁlter is a reusable piece of code that
can transform the content of HTTP requests, responses, and header information. Filters do not generally create a response or respond to a request as servlets do, rather they modify or adapt the requests for a resource, and modify or adapt responses from a resource.

Web Event & Listener Servlet Events javax.servlet.ServletContextListener javax.servlet.ServletContextAttributeListener Http Session
Events javax.servlet.http.HttpSessionListener javax.servlet.http.HttpSessionAttributeListener javax.servlet.http.HttpSessionActivationListener javax.servlet.http.HttpSessionBindingListener Servlet Request Events javax.servlet.ServletRequestListener javax.servlet.ServletRequestAttributeListener

Hello JSP It’s so easy: out.println(“Hello JSP”) Very features in
JSP should know Directive, Action, Taglibs & JSTL Expression Language (EL) Implicit Objects notorious scriptlet <% ... %>

ex. A heavy JSP Web Project Name: TodoJspWeb TODO list
A user can login/logout A user can create, update, and delete the todo item

JSP should be simple We ONLY USE page, taglib and
include directive @page for http header settings @taglib for jstl declaration @include for assemble page fragments EL to show variables Business Logic is not my business.

Java Web Programming Model Everything in JSP = Model 1
Web MVC = Model 2 ﬂow control in Servlet business logic delegate to other Object jsp for view only Everything in Servlet = Model Awesome ˿ɛഠ್ৎห

servlet/jsp container HTTP REQUEST Business Object Model 2 Flow Controller
(Servlet) Prepare View (JSP) HttpServletRequest HttpServletResponse HTTP RESPONSE Business Object set up data to {application, session, request, ...} show data from {application, session, request, ...}

ex. A Model 2 Web Project Name: TodoModel2Web A Mini
Web Framework web.framework.WebController web.framework.ActionMapper

Java Web Programming QA Any Questions or Suggestions !?

Java Web & JDBC Programming Introduction

Java Web & JDBC Programming Introduction

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