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

| '''Time'''

| '''Narration'''

| Welcome to the '''spoken-tutorial''' on  '''Servlet Methods.'''

| 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.

|Here we are using:'''Ubuntu '''Version '''12.04'''

| '''Firefox''' web-browser 21.0.

| To follow this tutorial, you must know:

|Core Java using '''Netbeans IDE'''  

|00:49

|'''HTML'''

|00:51

|Basics of '''Java Servlets '''and '''JSPs'''.

|If not, for relevant tutorials, please visit our website.

|First, we will create the '''Home page.'''

|The '''Home page''' will contain a simple '''login form'''.

|It will allow authenticated users to '''login''' to the '''Library Management System.'''

| Let us go to the '''index ''' '''dot''' '''jsp''' page that we had already modified earlier.

| Inside the body, we have a '''table''' with '''border''' equal to '''1.'''

| Inside the '''table''', we have included a heading '''Welcome to Library Management System.'''

| Next, we have a '''paragraph tag''' that includes ''' "This is the home page for Library Management System".'''

| Then we have a '''hyperlink''' which links to a '''page''' called '''visitorHomePage dot jsp.'''

| Next, we have a very simple '''login form.'''

| Before creating the '''form ''', you will have to create a '''servlet '''named '''GreetingServlet.'''

| So, pause the tutorial here and create a new '''servlet''' as explained in the earlier tutorial.  

| Note that the '''servlet''' name is '''GreetingServlet'''and

|the '''URL pattern''' should be '''GreetingServletPath.'''

| This''' form''' has two '''input elements''' - '''Username''' and '''Password.'''

| Next, we have a '''paragraph tag''' that includes a '''link''' to '''addUser.jsp.'''

|The first task is to retrieve the '''form''' '''data''' parameters.

| Type inside the''' doGet method''':

|'''PrintWriter space out equal to response dot getWriter().'''

| Next, we will retrieve the '''form data''' '''parameters'''.

| So that on the next line, type:

| '''String''' space '''username''' equal to '''request'''  dot '''getParameter ''' within brackets and double quotes '''userName''' and '''semicolon'''.

|Note that this '''userName '''is the name we have included in the '''form tag''' for '''User Name.'''

| Similarly, we will retrieve the password also.

|So, on the next line, type: '''String ''' space '''password''' equal to '''request''' dot '''getParameter ''' within brackets and double quotes '''password''' semicolon.

| Next, we will print the '''UserName '''in the '''output'''.

| So, on the next line, type:

|'''out''' dot '''println''' within brackets and double quotes ''' Hello from GET Method''' plus '''username.'''

| Now, to '''run''' this '''project''', right-click on '''MyFirstProject. '''

| Again right-click on '''MyFirstProject ''',  click on '''Run.'''

|We have got our '''Home page '''displayed in the '''browser'''.

| Observe that the title of the '''page''' is '''Home Page.'''

|06:06

| Now, the '''user '''was able to '''login''' here because we have not included any validation inside the code.  

|It is '''localhost ''' colon '''8080 ''' slash '''MyFirstProject ''' slash '''GreetingServletPath ''' question mark '''userName ''' equal to '''arya''' and '''password ''' equal to '''arya *123'''.

|Now, the '''form data '''is separated from the '''page''' information by a question mark.

| We can see that the '''username '''and '''password '''that we had entered in the '''form''' are inside the URL also.

| Now let us try to do the same, using '''POST Method.'''

| Copy the code we had written for  '''doGet method '''and paste in the '''doPost method.'''

| Now, let us open '''index dot jsp.'''

| Here, we must change the '''method attribute''' of the '''form tag '''to '''POST.'''

|We have '''form action ''' equal to '''GreetingServletPath''' '''method ''' equal to '''POST.'''

| Now, we will '''run''' this '''Project''' again.

| So, right-click on '''MyFirstProject '''and click on '''Run'''.

| We have got the output similar to the one we got when we used the '''GET method.'''

| So, let us type  '''UserName '''and '''Password '''again.

|It is '''localhost colon 8080 slash MyFirstProject slash GreetingServlet Path'''.

| Here, we do not see the '''form data '''in the '''URL '''of the '''request.'''

| This is the major difference between '''doGet '''and '''doPost methods.'''

| Now, let us learn when to use '''GET '''and when to use '''POST methods.'''

|'''GET method '''is used when:

|the '''form '''is small and hence the '''data '''is less.

|the '''user''' wants the contents of the data to be visible in the '''URL.'''

|'''POST method '''is used when:

|the '''form '''is large and hence the '''data '''is more.

|the '''user''' does not want the contents of the data to be visible in the '''URL.'''

|create a '''simple login form''' using '''JSP'''

|Pass parameters using '''doGet''' '''method'''

|Pass parameters using '''doPost method'''

|Difference between''' doGet '''and '''doPost''' methods.

| It summarizes the Spoken Tutorial Project.

|If you do not have good bandwidth, you can download and watch it.

| The Spoken Tutorial Project Team:

| Conducts workshops using spoken tutorials.

| Gives certificates for those who pass an online test.

| For more details please write to: contact at spoken hyphen tutorial dot org.

| Spoken Tutorial Project is a part of the "Talk to a Teacher" Project.

| It is supported by the National Mission on Education through ICT, MHRD, Government of India.

| The '''Library Management System''' has been contributed by a leading software MNC through their "Corporate Social Responsibility Programme".

|This is Arya Ratish from IIT Bombay, signing off. Thank you for joining.