Java-Business-Application/C2/Issuing-and-Returning-a-book/English-timed

Time	Narration
00:00	Welcome to the spoken-tutorial on Issuing and returning a book.
00:05	In this tutorial, we will learn how:
00:08	To fetch all the user details
00:11	To issue a book
00:13	To return a book.
00:15	Here we are using:
00:17	Ubuntu Version 12.04
00:20	Netbeans IDE 7.3
00:23	JDK 1.7
00:25	Firefox web-browser 21.0
00:29	You can use any web-browser of your choice.
00:33	To follow this tutorial, you must have knowledge of:
00:37	Basics of Java Servlets and JSPs
00:40	Creating and viewing inventories.
00:44	If not, for relevant tutorials please visit our website.
00:48	In the earlier tutorial, we had seen how the Admin Section works.
00:53	Here, in this tutorial, we have added more functionality to the Admin Section.
00:59	So, let us switch to the browser.
01:02	Let us login again as the admin.
01:05	We can see that we have two more options in the Admin Section Page - List Users and Checkout/Return Book.
01:14	Now, let us come to the IDE.
01:18	We can see that in the adminsection.jsp there are two more radio buttons.
01:24	One for List Users and the other for Checkout/Return Book.
01:30	Now, switch back to the browser.
01:33	We will click on the radio button for List Users.
01:38	It has all the details like First Name, Surname, Age, Gender and Username.
01:48	The steps are similar to the earlier two options;
01:51	we saw them in the previous tutorial.
01:55	Now, let us click on the next option which is to Checkout or Return Book.
02:01	We get a form which allows you to checkout as well as return book.
02:06	We will now see the code for the same.
02:09	Switch back to the IDE.
02:11	We clicked on Checkout/Return Book.
02:14	So menuSelection is equal to checkoutbook.
02:18	The steps are the same that we saw for List Books.
02:23	But here, we forward the request to checkOut.jsp using RequestDispatcher.
02:29	Now, let us come to checkOut dot jsp.
02:33	This page is similar to that of listBooks dot jsp
02:38	except that we have a radio button against each book
02:42	so that we can Checkout/Return that book.
02:46	We also have a User name field to get the username of the user who has to checkout the book.
02:53	We also have a Date field to set the return date of the book.
02:59	We have set the return date as one week from current date.
03:04	This is done using the class Calendar.
03:07	The add() function of this class takes two parameters.
03:13	The first is the present day of the year.
03:16	Second is the number of days to be added to the present day.
03:21	We have added seven days.
03:23	Now, note that form action is equal to CheckOutServlet.
03:29	Now, let us come back to the browser.
03:32	We will click on Book Id 1.
03:35	Type the username as arya.
03:38	We see that the return date is one week from today’s date.
03:43	Note that the number of Available Copies is 9.
03:48	Click on Checkout book.
03:51	We get the Checkout Success Page.
03:55	We will click on here to come to the Admin Section Page.
03:59	Again click on Checkout/Return Book.
04:03	We can see that the number of Available Copies reduces to 8.
04:08	We will see the code for this now.
04:10	Come back to the IDE.
04:13	Go to CheckOutServlet.java.
04:16	We have set the errorMsgs list.
04:19	We have set the errorMsgs in the request.
04:23	We get the username from the request using getParameter.
04:28	Similarly, we get checkout_book, return_book and book-id.
04:34	Next, we parse the book_id as Integer from the id.
04:40	We validate the userName and book id.
04:44	We also validate if Checkout_book and Return_Book are null.
04:50	Then, we validate if either of them is not null.
04:55	Here, we check if the user exists in the system using userExists method.
05:01	We then store the returned value of the method in userExists variable.
05:07	Now, we will see what we do in this method.
05:11	Here, first we execute the query to check if the username exists in the table.
05:18	Then we initialize the integer variable userExists to 0.
05:23	If the username exists then we set userExists to 1.
05:29	We then return the value of userExists.
05:33	So, if the method returns 0 then it means the user does not exist in the system.
05:42	else, if user exists then we call 'bookAlreadyIssued' method.
05:50	We then store the returned value of the method in bookIssued.
05:55	Here, we check if the same book has already been issued by the same user.
06:01	Now, let us come to bookAlreadyIssued method.
06:05	Here, we have set an integer variable bookAlreadyIssued to 0.
06:12	We execute the query to check if a book with the same book_id is issued by the same user.
06:18	We get the book_id from Checkout table.
06:23	If BookId exists then set the variable bookAlreadyIssued to 1.
06:30	We then return the value of bookAlreadyIssued.
06:34	So, if the method returns 1 then it means the same user has already borrowed this book.
06:43	Now, come back to the browser.
06:46	Now, let us try to checkout the same book by the same user.
06:51	Type the username as arya.
06:54	Click on the radio button against Book Id 1.
06:59	Then click on Checkout book.
07:03	We see that we get theerror message that "The same user has already borrowed this book".
07:10	Now, switch back to the IDE.
07:14	If userExists in the system and if the checkout_book is not null, we call checkout method.
07:22	Let us see what we do in this method.
07:25	Here, we get the availablecopies for the corresponding id.
07:31	We get this from Books table.
07:35	We then store the number of availablecopies into the variable availableCopies.
07:41	We check if availableCopies is greater than 0 and bookIssued is equal to 0.
07:50	We get the dateofreturn from the request and store it in returndate.
07:56	We then call insertIntoCheckout.
08:00	We will see what we do in insertIntoCheckout method.
08:05	Here, we store the book_id, userName and returndate into the Checkout table.
08:12	Then we call decrementAvailableCopies method.
08:16	We will see what we do in this method.
08:19	Here, we execute the query to decrement the Available Copies in the Books table by 1.
08:26	Then we call the setCheckoutIntoRequest method.
08:29	Let us come to this method.
08:32	In this method, we set the checkout attribute into the request.
08:38	Then we forward the request to successCheckout.jsp using RequestDispatcher.
08:45	If availableCopies is 0 then we print "There are no copies of the requested book available".
08:53	Now, let us come to successCheckout dot jsp.
08:58	Here, first we get the checkout attribute from the request.
09:03	We then display the success message for successful Checkout.
09:08	You can try out the different errors by yourself.
09:11	Now, let us return the book. So, switch to the browser.
09:15	Click on Book Id 1 and type the username as "arya".
09:21	Then, click on Return book.
09:24	We get the success message that book has been successfully returned.
09:29	Click on here for another checkout/return.
09:33	So, we come back to Admin Section Page.
09:36	Click on Checkout/Return Book.
09:39	We can see that the number of Available Copies has been incremented.
09:45	We will see the code for this.
09:47	Come back to the IDE.
09:49	Open CheckOutServlet dot java.
09:53	We check if userExists is equal to 1 AND return_book is not equal to null.
10:00	Then we call returnBook method.
10:03	Let us come to this method.
10:06	Here, we select the totalcopies and availablecopies from Books table for the Book Id.
10:14	We store the Total Copies and Available Copies to totcopies and availcopies.
10:21	Then we check if available copies exceed the total Copies.
10:27	Now, let us come back to the browser.
10:30	Let us now return a book for a user who has not borrowed the book.
10:35	Type the User name as mdhusein.
10:39	Click on Book Id 1.
10:42	Then click on Return book.
10:44	We can see that we get the error message: "The given user has not borrowed this book!!"
10:50	Now, come back to the IDE.
10:53	Here, we check if bookIssued is equal to 1.
10:57	We then call removeFromCheckout method.
11:01	Let us come to this method.
11:04	Here, we execute the query to delete from Checkout table the entry which has returned the book.
11:14	Then, we call incrementAvailableCopies method.
11:18	Let us come to this method.
11:21	Here, we increment the Available Copies by 1.
11:25	We execute the query to update in the Books table.
11:29	Then we call the setReturnIntoRequest method.
11:34	Let us come to this method.
11:37	Here, we set the returnBook attribute into the request.
11:41	Then we forward to successReturn page using RequestDispatcher.
11:48	The successReturn page is similar to that we had for successCheckout page.
11:53	Now, come back to the browser. Come back to the login page.
11:58	We can see that we have a link called Visitor’s Home Page.
12:03	We can see that we get a list of all the books available.
12:07	So, in this tutorial, we have learnt:
12:10	To list all the users
12:12	To fetch a book and To return a book.
12:15	To know more about the spoken tutorial project, watch the video available at the following link.
12:20	It summarizes the Spoken Tutorial Project.
12:24	If you do not have good bandwidth, you can download and watch it.
12:28	The Spoken Tutorial Project Team:
12:30	Conducts workshops using spoken tutorials.
12:32	Gives certificates to those who pass an online test.
12:36	For more details, please write to contact at spoken hyphen tutorial dot org.
12:41	Spoken Tutorial Project is a part of the "Talk to a Teacher" Project.
12:44	It is supported by the National Mission on Education through ICT, MHRD, Government of India.
12:50	More information on this mission is available at:
12:52	http://spoken-tutorial.org/NMEICT-Intro
12:58	The Library Management System has been contributed by a leading software MNC through their Corporate Social Responsibility Programme.
13:06	They have also validated the content for this spoken tutorial.
13:10	This is Arya Ratish from IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Sandhya.np14