Difference between revisions of "Java-Business-Application/C2/Servlet-Methods/English-timed"

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Revision as of 16:21, 18 September 2014

Time Narration
00.01 Welcome to the spoken-tutorial on Servlet Methods.
00.06 In this tutorial we will learn to
00.08 create a simple login form using JSP
00.13 Pass parameters using doGet method
00.16 Pass parameters using doPost method
00.20 Difference between doGet and doPost methods
00.25 Here we are using
00.26 Ubuntu Version 12.04
00.30 Netbeans IDE 7.3
00.33 JDK 1.7
00.36 Firefox web-browser 21.0
00.39 You can use any web-browser of your choice.
00.43 To follow this tutorial you must know
00.46 Core Java using Netbeans IDE
00.49 HTML
00.51 Basics of Java Servlets and JSPs
00.56 If not, for relevant tutorials please visit our website.
01.00 We will begin by creating our web application- the Library Management System.


01.06 First, we will create the home page.


01.09 The home page will contain a simple login form.


01.14 It will allow authenticated users to login to the Library Management System.
01.20 Now, let us switch to Netbeans IDE.
01.23 Let us go to the index dot jsp page, that we had already modified earlier.
01.30 I have modified this page to create our home page.
01.35 We keep the title as Home Page.
01.38 Inside the body, we have a table,with border equal to 1.
01.44 You can have a look at the code here.
01.47 Inside the table we have included a heading, Welcome to Library Management System.
01.54 Next, we have paragraph tag that includes, This is the home page for Library Management System.
02.03 Then, we have a hyperlink, which links to a page called visitorHomePage dot jsp.
02.11 We will create this page later.
02.13 Next,we have a very simple login form.
02.18 This form allows a registered user to login .
02.22 Before creating the form you will have to create a servlet named GreetingServlet.
02.28 Pause the tutorial and create a new servlet as explained in the earlier tutorial.
02.35 Note that the servlet name is GreetingServlet.
02.39 The URL pattern should be GreetingServletPath.
02.44 This form has two input elements - Username and Password.
02.50 It also has a Submit button that says Sign In.
02.55 Next, we have a paragraph tag that includes a link to addUser.jsp.
03.03 This is the registration page for those users who have not yet registered.
03.09 Now, let us go to our GreetingServlet.java.
03.14 Note that GreetingServlet.java is created in the same package org.spokentutorial.
03.23 Now, this servlet will be able to access the form data from the request object.
03.30 This servlet will act as a controller.


03.33 Do you recall that we had come across controller earlier?
03.38 Now, we will see what the servlet does as a controller.
03.42 The form data will reside in the request object.


03.46 The first task is to retrieve the form data parameters.
03.51 This is done using the getParameter method on the request object.
03.57 So, let us switch to Netbeans IDE.
04.02 Type inside the doGet method,
04.04 PrintWriter space out equal to response dot getWriter.
04.14 Next, we will retrieve the form data parameters.
04.18 So that on the next line type,
04.20 String' space username equal to request dot getParameter within brackets and double quotes userName'semicolon.
04.35 Note that this userName is the name we have included in the form tag for User Name.
04.43 Similarly, we will retrieve the password also.
04.48 So on the next line, type, String space password equal to request dot getParameter within brackets and double quotes password semicolon.
05.03 Next, we will print the User Name in the output.
05.08 So, on the next line type
05.10 'out dot println within brackets and double quotes Hello from GET Method plus username.
05.21 Now, to run this project, right-click on MyFirstProject.
05.27 Click on Clean and Build.
05.29 Again right click on MyFirstProject , click on Run.
05.35 So, the server is up and running.
05.38 It has deployed MyFirstProject.
05.41 We have got our home page displayed in the browser.
05.45 Observe that the title of the page is Home Page.
05.50 We can see a very simple login form here.
05.54 Let me enter the Username and Password.
05.58 I will type arya as the Username.
06.02 And arya*123 as the Password.
06.06 Then click on Sign In.
06.09 We can see that we have got the output Hello from GET Method arya.
06.15 Now, the user was able to login here because we have not included any validation inside the code.
06.24 We will do this in the later tutorial.
06.28 Now, have a look at the URL here.
06.31 It is localhost colon 8080 slash MyFirstProject slash GreetingServletPath question mark userName equal to arya and password equal to arya *123.
06.49 Now, form data is separated from the page information by a question mark.
06.56 We can see that username and password that we had entered in the form is inside the URL also.
07.05 Now, let us try to do the same using POST Method.
07.10 So, switch back to the IDE.
07.12 Copy the code we had written for doGet Method and paste in the doPost Method.
07.20 Now, change the println statement to Hello from POST Method.
07.27 Now, let us open index dot jsp.
07.31 Here, we must change the method attribute of the form tag to POST.
07.37 You can have a look at this code now.
07.42 We have form action equal to GreetingServletPath method equal to POST.
07.49 Now, we will run this Project again
07.53 So, Right click on MyFirstProject and click on Run
07.58 We have got an output similar to the one we got, when we used the GET method.
08.04 So let us type User Name and Password again.
08.08 Then click on Sign In.
08.12 Note that we have got Hello from POST Method arya.
08.17 Now, take a look at the URL.
08.19 It is localhost colon 8080 slash MyFirstProject slash GreetingServletPath
08.25 Here we do not see the form data in the URL of the request.
08.30 This is the major difference between doGet and doPost Methods.
08.35 Now, let us learn when to use GET and when to use POST Methods.
08.42 GET Method is used when:
08.44 the form is small and hence the data is less.
08.48 the user wants the contents of the data to be visible in the URL.
08.53 POST Method is used when:
08.55 the form is large and hence the data is more.
09.00 the user does not want the contents of the data to be visible in the URL.
09.06 ex: passwords
09.08 Let us summarize.
09.10 In this tutorial we have learnt to:
09.12 create a simple login form using JSP
09.16 Pass parameters using doGet method
09.19 Pass parameters using doPost method
09.22 Difference between doGet and doPost methods
09.26 Please make sure that you have completed this tutorial before proceeding further.
09.32 Watch the video available at the following link.
09.35 It summarizes the Spoken Tutorial Project
09.38 If you do not have good bandwidth you can download and watch it
09.42 The Spoken Tutorial Project Team
09.45 Conducts workshops using spoken tutorials
09.48 Gives certificates for those who pass an online test
09.52 For more details please write to contact at spoken hyphen tutorial dot org
09.58 Spoken Tutorial Project is a part of the Talk to a Teacher Project
10.02 It is supported by the National Mission on Education through ICT, MHRD, Government of India
10.09 More information on this mission is available at http://spoken-tutorial.org/NMEICT-Intro
10.19 The Library Management System has been contributed by a leading software MNC, through their Corporate Social Responsibility Programme.
10.28 They have also validated the content for this spoken tutorial.
10.32 This is Arya Ratish from IIT Bombay signing off.


Thank you for joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Sandhya.np14