this is a program to manage a simple library where a user can sign up, rent books... and librarians Supervise the actions taken in the library. this program does the user's and librarian's requests and saves book information in itself. it was done through objects and their methods. but don't have a database or work via files.
- User
- Library
- Book
- librarian
-
attributes methods method explanation username password Hash password hashs a string check password Checks the correctness of the given password set password sets a new password (required old password) books list get books prints the list of books that were rented by the user return book puts the book from book list in the library shlef rent book puts the book from the library shelf in the person's book list -
attributes methods method job name print status prints all attributes of the book author ISBN year of publish number decreaseBook decreases number of the book on library shelf increaseBook increases number of the book on library shelf getNum returns the number of book on the library shelf -
extended from user
attributes methods method job isActive checkActivity returns activity status changeActivity chenges activity status over riding checkPassword it is also considered activity status -
attributes methods method job list of books addBook adds a book that isn't in the library with a specified amount on the library shelf removeBook deletes a book from library searchBook calls the printStatus()method from the book objupdateBook updates year of publication of a book doesBookExist checks if the book is in the library or not decreaseBook deacreases the amount of book on the library self increaseBook increases the amount of book on the library self rentBook checks the adequate conditions and uses the rentBook()method of user objreturnBook checks the adequate conditions and uses the returnBook()method of user objlist of Users addUser adds a User that isn't in the library's notebook removeUser deletes a user from library's notebook searchUser calls the getBook()method from the user objupdateUser updated the password by knownig the old password doesUserExist checks if the user is in the library's notebook or not list of Librarians addLibrarian adds a Librarian that isn't in the library's notebook removeLibrarian deletes a Librarian from library's notebook searchLibrarian checks the activation of the librarian updateLibrarian change the activation of the librarian doesLibrarianExist checks if the Librarian is in the library's notebook or not login checks username and password and return the Specified value for each section
- User.hashPassword : uses the MD5 algorithm to hash passwords that is a secure way to save passwords in the database when the program wants to check the password, hashes an input password and then compares it with the hash string that was stored before.
- library.login :Checks the existence of user and validity of the password.
condition return number user with correct password 2 user with wrong password 1 librarian with wrong password -1 librarian with correct password -2 else 0
and handles the value of this return in the main class and then login to user or librarian page
- Books are stored in the library in hash map because each one have specefied ISBN code . Search, update, add... books work based on this property of books. This is the case for users and librarians according to their usernames.
- This program use swing GUI to get input and show outputs. this function
JOptionpane()creates a new window and does some stuff. - Implements encapsulation to protect data. so initials almost every variable to private mode so can access them only with that class method. but if initials a variable public it can be changed anywhere and can't check the validity of the data or can be dangerous for important data.
- In each function, for each action, the necessary logical conditions for the inputs are checked first, and then the given command is performed
- For testing, this program we set a default librarian and sign in and test all of the functions.
- The result is the program does well for each case but have a little bug so was fixed with no difficulty.
- special case: when a user inputs a non-numeric string when the program wants a numeric string it crashed because of the
Integer.parseInt()function so it needed to use this waytry{} catch{}
to detect crashes and handle them.
to solve this problem uses this function getNumberString() , This function ensures that the inputs consist of only numbers
with the help of this program, we can meet the needs of a library to manage. but this program needs a more beautiful user interface and a strong database or a appropriate server to have a connection between libraries to can be used in practical conditions.