今天这个是一个Java小练习，一个图书借阅系统，需要实现的功能有：
判断用户是否需要进行借书 在用户选择借书时，展示出图书列表 图书列表包含 图书序号、图书名称、借阅价格、作者 用户选择借书数量、并选择对应图书、借阅天数 计算出用户需支付金额Book.java
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package com.imooc;
/** * 图书类 包含图书序号 名称 价格 * */
public class Book { private int id; private String name; private double price; private String author;
public Book( int id, String name, double price, String author) { // TODO Auto-generated constructor stub this .id = id; this .setName(name); this .price = price; this .author = author; }
public void setId( int id) { this .id = id; }
public int getId() { return id; }
public void setPrice( double price) { this .price = price; }
public double getPrice() { return price; }
public void setAuthor(String author) { this .author = author; }
public String getAuthor() { return author; }
public void setName(String name) { this .name = name; }
public String getName() { return name; }
} |
BorrowBooks.java
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package com.imooc;
import java.util.ArrayList; import java.util.List; import java.util.Scanner;
public class BorrowBooks {
/** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub System.out.println( "~~~~~~~欢迎使用图书借阅系统~~~~~~~~ " ); System.out.println( "您是否要借书：1.是 >> 点击其他键退出" ); BorrowBooks test = new BorrowBooks(); while (test.test1()) { System.out.println( ">>>您可选择图书及其价目表：" ); System.out.println( "-------------------------------------------" ); Book[] books = { new Book( 0 , "红楼梦" , 12 , "曹雪芹" ), new Book( 1 , "西游记" , 12 , "吴承恩" ), new Book( 2 , "汉乡" , 12 , "孑与2" ), new Book( 3 , "大魏宫廷" , 12 , "贱宗首席" ), new Book( 4 , "三国演义" , 12 , "罗贯中" ), new Book( 5 , "水浒传" , 12 , "施耐庵" ) }; System.out.println( "序号" + " " + "\t" + "书名" + " " + "\t" + "租金" + " " + "\t" + "作者" ); for (Book book : books) { if (book.getClass().equals(Book. class )) { System.out.println(book.getId() + "\t" + "\t" + book.getName() + "\t" + "\t" + book.getPrice() + "/天" + "\t" + "\t" + book.getAuthor() + "/著" ); } } System.out.println( "-------------------------------------------" ); System.out.println( "-->请输入你要借书的数量：" ); Scanner zScanner = new Scanner(System.in); int BookNum = zScanner.nextInt(); if (BookNum > 0 ) { List<Book> bookList = new ArrayList<Book>(); int add = 0 ; int bookPrice = 0 ; for ( int i = 0 ; i < BookNum; i++) { System.out.println( ">>请输入第" + (i + 1 ) + "本书的序号：" ); int num = zScanner.nextInt(); try { bookList.add(books[num]); System.out.println( "----成功添加：" + bookList.get(add).getName()); if (books[num].getClass().equals(Book. class )) { bookPrice += ((Book) bookList.get(add)).getPrice(); } add++; } catch (Exception e) { // TODO: handle exception System.out.println( "您输入的图书序号不正确" ); i = i - 1 ; BookNum = BookNum; }
} System.out.println( "->请输入借阅的天数：" ); Scanner g = new Scanner(System.in); int bookDay = g.nextInt(); bookPrice = bookPrice * bookDay; System.out.println( "------------借阅选书完成------------" + "\n" + "下面开始统计数据.........." ); System.out.print( "您借阅的图书" + BookNum + "本：" + " " ); for (Book book : bookList) { System.out.println(book.getName() + " " + "\n" ); } System.out.println(); System.out.println( "共租用：" + bookDay + " 天" ); System.out.println( "需要付款：" + bookPrice + " 元" ); System.out.println( "->请输入付款金额：" ); System.out.println( "------------" ); Scanner x = new Scanner(System.in); int priceSpread = bookPrice - x.nextInt(); //定义差价 while (bookPrice != x.nextInt())
System.out.println( "------------" + "\n" + "输入错误，请重新输入金额！" );
/* while (bookPrice != x.nextInt()) { if (bookPrice > x.nextInt()) { int priceSpread = bookPrice - x.nextInt();//定义差价 System.out.println("------------" + "\n" + "您已付款" + x.nextInt() + "元，还需支付" + priceSpread + "元"); }
if (bookPrice <x.nextInt()) { int priceSpread = x.nextInt()-bookPrice ;//定义差价 System.out.println("------------" + "\n" + "您已付款" + x.nextInt() + "元，找您" + priceSpread + "元"); } */ System.out.println( "------------" ); System.out.println( " 交易成功！" ); System.out.println(); System.out.println( "------------感谢您的使用--------------" ); System.out.println( "………………继续借书请按1，退出请按其他键………………" ); } else { System.out.println( "您输入的借书数量为[0]，自动为您退出系统" ); System.exit( 0 ); }
}
}
private static Object bookPrice( int nextInt) { // TODO Auto-generated method stub return null ; }
// 捕获输入参数不正确异常 public boolean test1() { try { Scanner z = new Scanner(System.in); if (z.nextInt() == 1 ) { return true ; } else { return false ; } } catch (Exception e1) { return false ; } } } |
运行效果图
存在问题
在BorrowBooks.java这个Class中，下面这段代码本想实现判断用户输入的金额是否和应付金额一致，不一致时给出不同的回复，但是自己试了好多种方法，都没有实现，还是自己懂得太少：
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while (bookPrice != x.nextInt()) { if (bookPrice > x.nextInt()) { int priceSpread = bookPrice - x.nextInt(); //定义差价 System.out.println( "------------" + "\n" + "您已付款" + x.nextInt() + "元，还需支付" + priceSpread + "元" ); }
if (bookPrice <x.nextInt()) { int priceSpread = x.nextInt()-bookPrice ; //定义差价 System.out.println( "------------" + "\n" + "您已付款" + x.nextInt() + "元，找您" + priceSpread + "元" ); } } |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
原文链接：https://blog.csdn.net/weixin_41676971/article/details/81389989