Library Management System Using Switch Statement in Java

Here we are supposed to design and implement a simple library management system using a switch statement in Java, where have operated the following operations Add a new book, Check Out a book, display specific book status, search specific book, and display book details using different classes.

Menu for Library Management

Here is the list set of options that we will be creating that are as follows:

Exit Application
Add a New Book
Upgrade Quantity of a Book
Search a Book
Show All Books
Register Student
Show All Registered Students
Check Out Book
Check-In Book

Implementation:

We will be creating 5 files including our application(main) class responsible for the execution of our mini-project listed as follows:

Library
Students
Student
books
book

Note: As per naming conventions in java, it is good practice to have class initial with uppercase letter still here we are adhering with lowercase for better understanding of the code.

A. File: book.java

Java

// Java Program to Illustrate book Class that
// takes Input from the books and related information
 
package College;
 
// Importing required classes
import java.util.Scanner;
 
// Class
public class book {
 
    // Class data members
    public int sNo;
    public String bookName;
    public String authorName;
    public int bookQty;
    public int bookQtyCopy;
 
    // Creating object of Scanner class to
    // read input from users
    Scanner input = new Scanner(System.in);
 
    // Method
    // To add book details
    public book()
    {
        // Display message for taking input later
        // taking input via
        // nextInt() and nextLine() standard methods
        System.out.println("Enter Serial No of Book:");
        this.sNo = input.nextInt();
        input.nextLine();
 
        System.out.println("Enter Book Name:");
        this.bookName = input.nextLine();
 
        System.out.println("Enter Author Name:");
        this.authorName = input.nextLine();
 
        System.out.println("Enter Quantity of Books:");
        this.bookQty = input.nextInt();
        bookQtyCopy = this.bookQty;
    }
}

B. File: books.java

Java

// Java Program to Illustrate books class
// To Do all the Operations related to Books such as
// add, check-in, check-out,Valid books,Update books
 
// Importing required classes
import java.util.Scanner;
 
// CLass
public class books {
 
    // Class data members
    book theBooks[] = new book[50];
    public static int count;
 
    Scanner input = new Scanner(System.in);
 
    // Method 1
    //  To compare books
    public int compareBookObjects(book b1, book b2)
    {
 
        // If book name matches
        if (b1.bookName.equalsIgnoreCase(b2.bookName)) {
 
            // Printing book exists
            System.out.println(
                "Book of this Name Already Exists.");
            return 0;
        }
 
        // if book serial matches
        if (b1.sNo == b2.sNo) {
 
            // Print book exists
            System.out.println(
                "Book of this Serial No Already Exists.");
 
            return 0;
        }
        return 1;
    }
 
    // Method 2
    // To add book
    public void addBook(book b)
    {
 
        for (int i = 0; i < count; i++) {
 
            if (this.compareBookObjects(b, this.theBooks[i])
                == 0)
                return;
        }
 
        if (count < 50) {
 
            theBooks[count] = b;
            count++;
        }
        else {
 
            System.out.println(
                "No Space to Add More Books.");
        }
    }
 
    // Method 3
    // To search book by serial number
    public void searchBySno()
    {
 
        // Display message
        System.out.println(
            "\t\t\t\tSEARCH BY SERIAL NUMBER\n");
 
        // Class data members
        int sNo;
        System.out.println("Enter Serial No of Book:");
        sNo = input.nextInt();
 
        int flag = 0;
        System.out.println(
            "S.No\t\tName\t\tAuthor\t\tAvailable Qty\t\tTotal Qty");
 
        for (int i = 0; i < count; i++) {
            if (sNo == theBooks[i].sNo) {
                System.out.println(
                    theBooks[i].sNo + "\t\t"
                    + theBooks[i].bookName + "\t\t"
                    + theBooks[i].authorName + "\t\t"
                    + theBooks[i].bookQtyCopy + "\t\t"
                    + theBooks[i].bookQty);
                flag++;
                return;
            }
        }
        if (flag == 0)
            System.out.println("No Book for Serial No "
                               + sNo + " Found.");
    }
 
    // Method 4
    // To search author by name
    public void searchByAuthorName()
    {
 
        // Display message
        System.out.println(
            "\t\t\t\tSEARCH BY AUTHOR'S NAME");
 
        input.nextLine();
 
        System.out.println("Enter Author Name:");
        String authorName = input.nextLine();
 
        int flag = 0;
 
        System.out.println(
            "S.No\t\tName\t\tAuthor\t\tAvailable Qty\t\tTotal Qty");
 
        for (int i = 0; i < count; i++) {
 
            // if author matches any of its book
            if (authorName.equalsIgnoreCase(
                    theBooks[i].authorName)) {
 
                // Print below corresponding credentials
                System.out.println(
                    theBooks[i].sNo + "\t\t"
                    + theBooks[i].bookName + "\t\t"
                    + theBooks[i].authorName + "\t\t"
                    + theBooks[i].bookQtyCopy + "\t\t"
                    + theBooks[i].bookQty);
                flag++;
            }
        }
 
        // Else no book matches for author
        if (flag == 0)
            System.out.println("No Books of " + authorName
                               + " Found.");
    }
 
    // Method 5
    // To display all books
    public void showAllBooks()
    {
 
        System.out.println("\t\t\t\tSHOWING ALL BOOKS\n");
        System.out.println(
            "S.No\t\tName\t\tAuthor\t\tAvailable Qty\t\tTotal Qty");
 
        for (int i = 0; i < count; i++) {
 
            System.out.println(
                theBooks[i].sNo + "\t\t"
                + theBooks[i].bookName + "\t\t"
                + theBooks[i].authorName + "\t\t"
                + theBooks[i].bookQtyCopy + "\t\t"
                + theBooks[i].bookQty);
        }
    }
 
    // Method 6
    // To edit the book
    public void upgradeBookQty()
    {
 
        System.out.println(
            "\t\t\t\tUPGRADE QUANTITY OF A BOOK\n");
        System.out.println("Enter Serial No of Book");
 
        int sNo = input.nextInt();
 
        for (int i = 0; i < count; i++) {
 
            if (sNo == theBooks[i].sNo) {
 
                // Display message
                System.out.println(
                    "Enter No of Books to be Added:");
 
                int addingQty = input.nextInt();
                theBooks[i].bookQty += addingQty;
                theBooks[i].bookQtyCopy += addingQty;
 
                return;
            }
        }
    }
 
    // Method 7
    // To create menu
    public void dispMenu()
    {
 
        // Displaying menu
        System.out.println(
            "----------------------------------------------------------------------------------------------------------");
        System.out.println("Press 1 to Add new Book.");
        System.out.println("Press 0 to Exit Application.");
        System.out.println(
            "Press 2 to Upgrade Quantity of a Book.");
        System.out.println("Press 3 to Search a Book.");
        System.out.println("Press 4 to Show All Books.");
        System.out.println("Press 5 to Register Student.");
        System.out.println(
            "Press 6 to Show All Registered Students.");
        System.out.println("Press 7 to Check Out Book. ");
        System.out.println("Press 8 to Check In Book");
        System.out.println(
            "-------------------------------------------------------------------------------------------------------");
    }
 
    // Method 8
    // To search the library
    public int isAvailable(int sNo)
    {
 
        for (int i = 0; i < count; i++) {
            if (sNo == theBooks[i].sNo) {
                if (theBooks[i].bookQtyCopy > 0) {
 
                    System.out.println(
                        "Book is Available.");
                    return i;
                }
                System.out.println("Book is Unavailable");
                return -1;
            }
        }
 
        System.out.println("No Book of Serial Number "
                           + " Available in Library.");
        return -1;
    }
 
    // Method 9
    // To remove the book from the library
    public book checkOutBook()
    {
 
        System.out.println(
            "Enter Serial No of Book to be Checked Out.");
        int sNo = input.nextInt();
 
        int bookIndex = isAvailable(sNo);
 
        if (bookIndex != -1) {
            theBooks[bookIndex].bookQtyCopy--;
            return theBooks[bookIndex];
        }
        return null;
    }
 
    // Method 10
    // To add the Book to the Library
    public void checkInBook(book b)
    {
        for (int i = 0; i < count; i++) {
            if (b.equals(theBooks[i])) {
                theBooks[i].bookQtyCopy++;
                return;
            }
        }
    }
}

C. File: Student.java

Java

// Java Program to Illustrate Student Class
// to take Input from the student and related Information
 
// Importing required classes
import java.util.Scanner;
 
// Class
public class student {
 
    // Class member variables
    String studentName;
    String regNum;
 
    book borrowedBooks[] = new book[3];
    public int booksCount = 0;
 
    // Creating object of Scanner class to
    // take input from user
    Scanner input = new Scanner(System.in);
 
    // Constructor
    public student()
    {
        // Print statement
        System.out.println("Enter Student Name:");
 
        // This keywords refers to current instance
        this.studentName = input.nextLine();
 
        // Print statement
        System.out.println("Enter Registration Number:");
        this.regNum = input.nextLine();
    }
}

D. File: students.java

Java

// Java Program to Illustrate students Class
// To Do all the Operations related to students:
// add Students,check-in books,check out books,ValidStudent
 
// Importing required classes
import java.util.Scanner;
 
// Class
public class students {
 
    // Creating objects of Scanner and students class
    Scanner input = new Scanner(System.in);
    student theStudents[] = new student[50];
 
    public static int count = 0;
 
    // Method 1
    // To add books
    public void addStudent(student s)
    {
        for (int i = 0; i < count; i++) {
 
            if (s.regNum.equalsIgnoreCase(
                    theStudents[i].regNum)) {
 
                // Print statement
                System.out.println(
                    "Student of Reg Num " + s.regNum
                    + " is Already Registered.");
 
                return;
            }
        }
 
        if (count <= 50) {
            theStudents[count] = s;
            count++;
        }
    }
 
    // Method 2
    // Displaying all students
    public void showAllStudents()
    {
        // Printing student name and
        // corresponding registered number
        System.out.println("Student Name\t\tReg Number");
        for (int i = 0; i < count; i++) {
 
            System.out.println(theStudents[i].studentName
                               + "\t\t"
                               + theStudents[i].regNum);
        }
    }
 
    // Method 3
    // To check the Student
    public int isStudent()
    {
        // Display message only
        System.out.println("Enter Reg Number:");
 
        String regNum = input.nextLine();
 
        for (int i = 0; i < count; i++) {
 
            if (theStudents[i].regNum.equalsIgnoreCase(
                    regNum)) {
                return i;
            }
        }
 
        // Print statements
        System.out.println("Student is not Registered.");
        System.out.println("Get Registered First.");
 
        return -1;
    }
 
    // Method 4
    // To remove the book
    public void checkOutBook(books book)
    {
        int studentIndex = this.isStudent();
 
        if (studentIndex != -1) {
            System.out.println("checking out");
 
            book.showAllBooks();
            book b = book.checkOutBook();
 
            System.out.println("checking out");
            if (b != null) {
 
                if (theStudents[studentIndex].booksCount
                    <= 3) {
 
                    System.out.println("adding book");
                    theStudents[studentIndex].borrowedBooks
                        [theStudents[studentIndex]
                             .booksCount]
                        = b;
                    theStudents[studentIndex].booksCount++;
 
                    return;
                }
                else {
 
                    System.out.println(
                        "Student Can not Borrow more than 3 Books.");
                    return;
                }
            }
            System.out.println("Book is not Available.");
        }
    }
 
    // Method 5
    // To add the book
    public void checkInBook(books book)
    {
        int studentIndex = this.isStudent();
        if (studentIndex != -1) {
 
            // Printing credentials corresponding to student
            System.out.println(
                "S.No\t\t\tBook Name\t\t\tAuthor Name");
 
            student s = theStudents[studentIndex];
 
            for (int i = 0; i < s.booksCount; i++) {
 
                System.out.println(
                    s.borrowedBooks[i].sNo + "\t\t\t"
                    + s.borrowedBooks[i].bookName + "\t\t\t"
                    + s.borrowedBooks[i].authorName);
            }
 
            // Display message only
            System.out.println(
                "Enter Serial Number of Book to be Checked In:");
 
            int sNo = input.nextInt();
 
            for (int i = 0; i < s.booksCount; i++) {
                if (sNo == s.borrowedBooks[i].sNo) {
                    book.checkInBook(s.borrowedBooks[i]);
                    s.borrowedBooks[i] = null;
 
                    return;
                }
            }
 
            System.out.println("Book of Serial No " + sNo
                               + "not Found");
        }
    }
}

E. File: Library.java

Java

// Java Program to Illustrate Application CLass
// To Create The Menu For the Program
 
// Importing required classes
import java.util.Scanner;
 
// Class
public class Library {
 
    // Main driver method
    public static void main(String[] args)
    {
        // Creating object of Scanner class
        // to take input from user
        Scanner input = new Scanner(System.in);
 
        // Displaying menu
        System.out.println(
            "********************Welcome to the GFG Library!********************");
        System.out.println(
            "                  Select From The Following Options:               ");
        System.out.println(
            "**********************************************************************");
 
        // Creating object of book class
        books ob = new books();
        // Creating object of students class
        students obStudent = new students();
 
        int choice;
        int searchChoice;
 
        // Creating menu
        // using do-while loop
        do {
 
            ob.dispMenu();
            choice = input.nextInt();
 
            // Switch case
            switch (choice) {
 
                // Case
            case 1:
                book b = new book();
                ob.addBook(b);
                break;
 
                // Case
            case 2:
                ob.upgradeBookQty();
                break;
 
            // Case
            case 3:
 
                System.out.println(
                    " press 1 to Search with Book Serial No.");
                System.out.println(
                    " Press 2 to Search with Book's Author Name.");
                searchChoice = input.nextInt();
 
                // Nested switch
                switch (searchChoice) {
 
                    // Case
                case 1:
                    ob.searchBySno();
                    break;
 
                    // Case
                case 2:
                    ob.searchByAuthorName();
                }
                break;
 
                // Case
            case 4:
                ob.showAllBooks();
                break;
 
                // Case
            case 5:
                student s = new student();
                obStudent.addStudent(s);
                break;
 
                // Case
            case 6:
                obStudent.showAllStudents();
                break;
 
                // Case
            case 7:
                obStudent.checkOutBook(ob);
                break;
 
                // Case
            case 8:
                obStudent.checkInBook(ob);
                break;
 
                // Default case that will execute for sure
                // if above cases does not match
            default:
 
                // Print statement
                System.out.println("ENTER BETWEEN 0 TO 8.");
            }
 
        }
 
        // Checking condition at last where we are
        // checking case entered value is not zero
        while (choice != 0);
    }
}