网站报301错误广州白云区疫情实时动态

1.概述

书城的基本功能：

1. 展示书籍
2. 上新书籍
3. 下架书籍
4. 退出应用

书城项目所涉及到的知识点：

1. 用户交互–键盘录入
2. 分支结构，循环结构
3. 面向对象的思维，封装对象
4. 集合的使用

2.菜单的编写

这部分代码就是读取用户键盘的录入，然后执行菜单功能

package bookstorw;import java.util.Scanner;public class Test {public static void main(String[] args) {while(true) {System.out.println("欢迎来到书城：");System.out.println("1.展示书籍：");System.out.println("2.上新书籍：");System.out.println("3.下架书籍：");System.out.println("4.退出应用：");//借助Scanner类,扫描键盘输入Scanner sc = new Scanner(System.in);System.out.println("请输入整数序号。");//获取键盘输入的整数值int choice = sc.nextInt();if (choice == 1) {System.out.println("1>>>>>展示书籍");}if (choice == 2) {System.out.println("2>>>>>上新书籍");}if (choice == 3) {System.out.println("3>>>>>下架书籍");}if (choice == 4) {System.out.println("4>>>>>退出应用");break;}}}}

3.上新书籍

此处应当抽象出来一个书籍的类。每新增书籍，我们都应该实例化该类。
创建一个书籍对象，他有三个属性，书号，书籍名字还有作者名

package bookstorw;public class Book {//书籍编号private int bno;//书籍名称private String bname;//书籍作者private String bwriter;public int getBno() {return bno;}public void setBno(int bno) {this.bno = bno;}public String getBwriter() {return bwriter;}public void setBwriter(String bwriter) {this.bwriter = bwriter;}public String getBname() {return bname;}public void setBname(String bname) {this.bname = bname;}public Book() {}public Book(int bno, String bname, String bwriter) {this.bno = bno;this.bname = bname;this.bwriter = bwriter;}public static void main(String[] args) {}
}

然后重写choice==2这个分支

if (choice == 2) {System.out.println("2>>>>>上新书籍");//从键盘录入书籍信息System.out.println("请输入书籍编号：");int bNo = sc.nextInt();System.out.println("请输入书籍名字：");String bName = sc.next();System.out.println("请输入书籍作者：");String bWriter = sc.next();//创建一个书籍对象Book b = new Book();b.setBno(bNo);b.setBname(bName);b.setBwriter(bWriter);list.add(b);  }

在while循环前创建一个集合，这样这个集合的作用域更大，在choice==1的时候也可以使用

4.展示书籍与下架书籍

重写choice==1
for循环来遍历输出集合里的所有对象

if (choice == 1) {System.out.println("1>>>>>展示书籍");for(int i = 0;i <= list.size() - 1; i++){//获取到i之后，将他强制转换为book类型的对象Book b = (Book)(list.get(i));System.out.println(b.getBno()+"----"+b.getBname()+"-----"+b.getBwriter());}}

下架书籍
遍历整个集合对象，寻找与所输入的整型相等的书籍编号，然后删除

if (choice == 3) {System.out.println("3>>>>>下架书籍");System.out.println("录入需要下架的书籍的编号：");int deleteBook = sc.nextInt();for(int i = 0;i <= list.size() - 1; i++){//获取到i之后，将他强制转换为book类型的对象Book b = (Book)(list.get(i));if(b.getBno() == deleteBook){list.remove(b);System.out.println("书籍下架成功。");break;}}}

5.全部代码

总共两个文件
Test.java

package bookstorw;import java.util.ArrayList;
import java.util.Scanner;public class Test {public static void main(String[] args) {//创建一个集合，存放书籍对象ArrayList list = new ArrayList();while(true) {System.out.println("欢迎来到书城：");System.out.println("1.展示书籍：");System.out.println("2.上新书籍：");System.out.println("3.下架书籍：");System.out.println("4.退出应用：");//借助Scanner类,扫描键盘输入Scanner sc = new Scanner(System.in);System.out.println("请输入整数序号。");//获取键盘输入的整数值int choice = sc.nextInt();if (choice == 1) {System.out.println("1>>>>>展示书籍");for(int i = 0;i <= list.size() - 1; i++){//获取到i之后，将他强制转换为book类型的对象Book b = (Book)(list.get(i));System.out.println(b.getBno()+"----"+b.getBname()+"-----"+b.getBwriter());}}if (choice == 2) {System.out.println("2>>>>>上新书籍");//从键盘录入书籍信息System.out.println("请输入书籍编号：");int bNo = sc.nextInt();System.out.println("请输入书籍名字：");String bName = sc.next();System.out.println("请输入书籍作者：");String bWriter = sc.next();//创建一个书籍对象Book b = new Book();b.setBno(bNo);b.setBname(bName);b.setBwriter(bWriter);list.add(b);}if (choice == 3) {System.out.println("3>>>>>下架书籍");System.out.println("录入需要下架的书籍的编号：");int deleteBook = sc.nextInt();for(int i = 0;i <= list.size() - 1; i++){//获取到i之后，将他强制转换为book类型的对象Book b = (Book)(list.get(i));if(b.getBno() == deleteBook){list.remove(b);System.out.println("书籍下架成功。");break;}}}if (choice == 4) {System.out.println("4>>>>>退出应用");break;}}}}

Book.java

package bookstorw;public class Book {//书籍编号private int bno;//书籍名称private String bname;//书籍作者private String bwriter;public int getBno() {return bno;}public void setBno(int bno) {this.bno = bno;}public String getBwriter() {return bwriter;}public void setBwriter(String bwriter) {this.bwriter = bwriter;}public String getBname() {return bname;}public void setBname(String bname) {this.bname = bname;}public Book() {}public Book(int bno, String bname, String bwriter) {this.bno = bno;this.bname = bname;this.bwriter = bwriter;}public static void main(String[] args) {}
}