使用 Java 中的 Switch 语句的图书馆管理系统

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在当今科技时代，图书馆已经认识到图书馆管理系统作为有效处理其资料的宝贵资源的广泛能力。为了优化这些系统，必须利用强大的编程语言（如 Java），它可以帮助创建高效且用户友好的解决方案。作为示例，本文将使用 Java 中的 switch 语句来演示图书馆管理系统的实现。从而使图书馆能够更好地组织和优化其资源，以满足其用户不断增长的需求。

图书馆管理菜单

我们将生成的备选方案如下所示：

• 退出应用程序

• 添加新书

• 升级图书数量

• 搜索图书

• 显示所有图书

• 注册学生

• 显示所有已注册学生

• 借书

• 还书

实现

除了我们的应用程序（主）类（负责执行我们的迷你项目）之外，我们还将创建以下五个文件：

• 图书馆

• 学生

• 学生列表

• 图书

• 图书列表

示例

文件：book.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;
   }
}

文件：books.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;
         }
      }
   }
}

文件：Student.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();
   }
}

文件：Students.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");
      }
   }
}

文件：Library.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 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);
   }
}

输出

添加图书

********************Welcome to the Library!********************
                   Select From The Following Options:
***************************************************************
---------------------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
--------------------------------------------------------------
1
Enter Serial No of Book:
1
Enter Book Name:
Fate- the most unreliable thing
Enter Author Name:
Aashi Gupta
Enter Quantity of Books:
10

注册学生

------------------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
------------------------------------------------------------
5
Enter Student Name:
Anubhav Gupta
Enter Registration Number:
0001

借书

-----------------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
-----------------------------------------------------------
7
Enter Registration Number:
0001
checking out
                            SHOWING ALL BOOKS
S No           Name                    Author             Available Quantity
1            Fate- the most            Aashi Gupta              10
             Unreliable thing
Enter Serial No of Book to be Checked Out.
1
Book is Available.
checking out
adding book

显示所有图书

---------------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
--------------------------------------------------------
4
                         SHOWING ALL BOOKS
S No             Name                Author             Available Qty
1             Fate- the most        Aashi Gupta             9
              Unreliable thing

还书

------------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
----------------------------------------------------
8
Enter Registration Number:
0001
S No           Book Name                                     Author Name
1             Fate- the most unreliable thing                Aashi Gupta
Enter Serial Number of Book to be Checked In:
1

更新图书数量

--------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
--------------------------------------------------
2
                       UPGRADE QUANTITY OF BOOK
Enter Serial No of Book:
1
Enter No of Books to be Added:
1

搜索图书

--------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
--------------------------------------------------
3
Press 1 to Search with Book Serial No.
Press 2 to Search with Book’s Author Name.
2
                          SEARCH BY AUTHOR’S NAME
Enter Author Name:
Aashi Gupta
S No         Name         Author          Available Qty           Total Qty
1            Fate         Aashi Gupta       11                      11

显示所有已注册学生

------------------------------------------------
Press 0 to Exit Application.
Press 1 to Add new Book. 
Press 2 to Upgrade Quantity of Book.
Press 3 to Search a Book.
Press 4 to Show All Books.
Press 5 to Register Student.
Press 6 to Show All Registered Students.
Press 7 to Check Out Book.
Press 8 to Check In Book.
------------------------------------------------
6
Student Name                          Registration Number
Anubhav Gupta                              0001

结论

Java 中的 switch 语句可用于图书馆管理系统，以获得全面的用户体验。Java 的功能可以用来创建一个复杂但用户友好的平台，能够自动化管理职责，同时确保满足安全标准。结果将是一个创新的解决方案，使图书馆工作人员能够轻松管理资源，同时为客户/用户/读者分配更多时间和资源，以提供令人满意的体验。通过巧妙地集成 switch 语句，可以确保图书馆的系统具有额外的复杂性层，以帮助增强稳健性。基于 Java 的更通用的图书馆管理系统保证了改进的功能和更令工作人员和读者放心的体验。