ADD file via upload

Book.java

@@ -0,0 +1,24 @@
+package jichuti1;
+
+/**
+ * 图书类
+ */
+public class Book {
+    private String bookId;        // 图书ID
+    private String title;         // 书名
+    private String author;        // 作者
+    private boolean isAvailable;  // 是否可借
+
+    public Book(String bookId, String title, String author) {
+        this.bookId = bookId;
+        this.title = title;
+        this.author = author;
+        this.isAvailable = true;
+    }
+
+    // getter和setter
+    public String getBookId() { return bookId; }
+    public String getTitle() { return title; }
+    public boolean isAvailable() { return isAvailable; }
+    public void setAvailable(boolean available) { isAvailable = available; }
+}