Java异常之图书管理系统
本文实例为大家分享了Java异常之图书管理系统的具体代码,供大家参考,具体内容如下
模拟借书系统,任务要求:
感觉自己的写出来的代码不够简洁,参考了其他的案例写了一个,效果如下:
结构:
运行异常1:
运行异常2:
运行异常3:
正常运行:
1、名称查询
2、序号查询:
Book.java:
package com.tony; /* * 图书租赁系统 */ public class Book { public String bookName; public int bookId; public Book(String bookName, int bookId){ this.bookName = bookName; this.bookId = bookId; } }
自定义异常类MyException.java:
package com.tony; /* * 自定义异常类 */ public class MyException extends Exception{ //有参构造方法 public MyException(String message) { super(message); }; }
BorrowBook.java:
package com.tony; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Scanner; /* * 主程序 */ public class BorrowBook { Book book [] = {new Book("高等数学", 1), new Book("大学英语", 2), new Book("Android", 3), new Book("会计基础", 4)}; public List<Book> listBooks; //无参构造方法 public BorrowBook() { this.listBooks = new ArrayList<Book>(); } public void addBook(){ listBooks.addAll(Arrays.asList(book)); } public void systemOut() { System.out.println("*******欢迎使用借书系统*******"); System.out.println("*-*-*-*图书一览表:*-*-*-*"); System.out.println(" 书名" + "\t\t" + "序号"); for(Book book:listBooks) { System.out.println(book.bookName + "\t\t " +book.bookId); } } private Scanner scanner = new Scanner(System.in); public static void main(String[] args) { BorrowBook borrowBook = new BorrowBook(); borrowBook.addBook(); borrowBook.systemOut(); while(true) { System.out.println("输入命令:1-按照名称查找图书;2-按照序号查找图书"); switch (borrowBook.scanf()) { case 1://根据用户不同的输入内容执行 try { System.out.println("书籍:" + borrowBook.findByName()); break; } catch (Exception e) { System.out.println(e.getMessage()); continue; } case 2: try { System.out.println("书籍:" + borrowBook.findById()); break; } catch (Exception e) { System.out.println(e.getMessage()); continue; } default: System.out.println("命令错误,请重试."); continue; } break; } borrowBook.scanner.close(); } public String findByName() throws MyException{ System.out.println("*****请输入书籍的名称-->"); String name = scanner.next(); for (Book books : book) { if (name.equals(books.bookName)) { return books.bookName + "\t序号:" +books.bookId; } } throw new MyException("名称错误,请重试."); } public String findById() throws MyException { System.out.println("*****请输入书籍的序号-->"); int in = scanner.nextInt(); for (int i = 0; i < book.length; i++) { if (in == (i + 1)) { return book[i].bookName + "\t序号:" + (i+1); } } throw new MyException("下标越界,请重试."); } public int scanf() { try { int in = scanner.nextInt(); return in; } catch(Exception e) { scanner = new Scanner(System.in); return -1; } } }
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