style:fmt

com/study/demo3/Bicycle.java

@@ -1,4 +1,5 @@
 package com.study.demo3;
+
 public class Bicycle extends Vehicle {
   @Override
   public void start() {

com/study/demo3/Book.java

@@ -5,26 +5,22 @@ public class Book {
   protected String title;
   protected boolean available;
 
-   
   public Book() {
     this.available = true;
   }
 
-   
   public Book(String isbn, String title) {
     this.isbn = isbn;
     this.title = title;
     this.available = true;
   }
 
-   
   public Book(String isbn, String title, boolean available) {
     this.isbn = isbn;
     this.title = title;
     this.available = available;
   }
 
-   
   public String getIsbn() {
     return isbn;
   }
@@ -49,11 +45,11 @@ public class Book {
     this.available = available;
   }
 
-   
   public void returnBook() {
     if (!this.available) {
       this.available = true;
-            System.out.println(this.title + " (ISBN: " + this.isbn + ") has been returned and is now available.");
+      System.out.println(
+          this.title + " (ISBN: " + this.isbn + ") has been returned and is now available.");
     } else {
       System.out.println(this.title + " (ISBN: " + this.isbn + ") is already available.");
     }

com/study/demo3/Car.java

@@ -1,7 +1,7 @@
 package com.study.demo3;
+
 public class Car extends Vehicle {
   @Override
-   
   public void start() {
     System.out.println("The car is started");
   }

com/study/demo3/EBook.java

@@ -1,20 +1,17 @@
 package com.study.demo3;
+
 public class EBook extends Book {
   private double fileSize;
 
-   
   public EBook() {
     super();
   }
 
-   
-   
   public EBook(String isbn, String title, double fileSize) {
     super(isbn, title);
     this.fileSize = fileSize;
   }
 
-   
   public double getFileSize() {
     return fileSize;
   }
@@ -25,6 +22,14 @@ public class EBook extends Book {
 
   @Override
   public String toString() {
-        return "EBook [ISBN=" + isbn + ", Title=" + title + ", FileSize=" + fileSize + "MB, Available=" + available + "]";
+    return "EBook [ISBN="
+        + isbn
+        + ", Title="
+        + title
+        + ", FileSize="
+        + fileSize
+        + "MB, Available="
+        + available
+        + "]";
   }
 }

com/study/demo3/Library.java

@@ -1,8 +1,9 @@
 package com.study.demo3;
+
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.ArrayList;
 
 public class Library {
 
@@ -12,12 +13,9 @@ public class Library {
     this.books = new HashMap<>();
   }
 
-   
-   
   public void addBook(Book b) {
     String isbn = b.getIsbn();
 
-       
     if (books.containsKey(isbn)) {
       System.out.println("The book already exists, adding it failed.");
     } else {
@@ -26,12 +24,9 @@ public class Library {
     }
   }
 
-   
-   
   public List<Book> searchAvailableBooks() {
     List<Book> availableBooks = new ArrayList<>();
 
-       
     for (Book book : books.values()) {
       if (book.isAvailable()) {
         availableBooks.add(book);

com/study/demo3/LibraryTest.java

@@ -1,26 +1,22 @@
 package com.study.demo3;
+
 import java.util.List;
 
 public class LibraryTest {
   public static void main(String[] args) {
     Library lib = new Library();
 
-       
     EBook e1 = new EBook("E001", "Java Basics", 5.2);
 
     e1.setAvailable(false);
 
-       
     PrintedBook p1 = new PrintedBook("P001", "Design Patterns", 3);
 
-       
     lib.addBook(e1);
     lib.addBook(p1);
 
-       
     lib.addBook(p1);
 
-       
     System.out.println("\n--- 可借阅图书列表 (available = true) ---");
     List<Book> availableList = lib.searchAvailableBooks();
 
@@ -33,7 +29,6 @@ public class LibraryTest {
       }
     }
 
-       
     e1.returnBook();
     System.out.println("\n--- 恢复 e1 后可借阅图书列表 ---");
     availableList = lib.searchAvailableBooks();

com/study/demo3/Main3.java

@@ -1,4 +1,5 @@
 package com.study.demo3;
+
 public class Main {
   public static void main(String[] args) {
 
@@ -7,15 +8,12 @@ public class Main {
     EBook ebook = new EBook("123-456", "Java Programming", 2.5);
     System.out.println("EBook Status (Initial): " + ebook.toString());
 
-       
     ebook.setAvailable(false);
     System.out.println("EBook Status (Borrowed): " + ebook.toString());
 
-       
     ebook.returnBook();
     System.out.println("EBook Status (After Return): " + ebook.toString());
 
-       
     System.out.println("\n--- 测试 PrintedBook ---");
     PrintedBook pbook = new PrintedBook();
     pbook.setIsbn("789-012");
@@ -23,11 +21,9 @@ public class Main {
     pbook.setStock(10);
     System.out.println("PBook Status (Initial): " + pbook.toString());
 
-       
     pbook.setAvailable(false);
     System.out.println("PBook Status (Borrowed): " + pbook.toString());
 
-       
     pbook.returnBook();
     System.out.println("PBook Status (After Return): " + pbook.toString());
   }

com/study/demo3/PrintedBook.java

@@ -1,19 +1,17 @@
 package com.study.demo3;
+
 public class PrintedBook extends Book {
   private int stock;
 
-   
   public PrintedBook() {
     super();
   }
 
-   
   public PrintedBook(String isbn, String title, int stock) {
     super(isbn, title);
     this.stock = stock;
   }
 
-   
   public int getStock() {
     return stock;
   }
@@ -24,6 +22,14 @@ public class PrintedBook extends Book {
 
   @Override
   public String toString() {
-        return "PrintedBook [ISBN=" + isbn + ", Title=" + title + ", Stock=" + stock + ", Available=" + available + "]";
+    return "PrintedBook [ISBN="
+        + isbn
+        + ", Title="
+        + title
+        + ", Stock="
+        + stock
+        + ", Available="
+        + available
+        + "]";
   }
 }

com/study/demo3/StudentManager.java

@@ -1,4 +1,5 @@
 package com.study.demo3;
+
 import java.util.*;
 
 public class StudentManager {

com/study/demo3/Train.java

@@ -1,4 +1,5 @@
 package com.study.demo3;
+
 public class Train extends Vehicle {
   @Override
   public void start() {

com/study/demo3/Vehicle.java

@@ -1,4 +1,5 @@
 package com.study.demo3;
+
 public class Vehicle {
   protected String name;