From a3e84dc5166c14a8b400adfa6b7d2ad543ee7084 Mon Sep 17 00:00:00 2001 From: seahi Date: Wed, 9 Oct 2024 11:06:06 +0800 Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E6=94=B9=E9=A1=B9=E7=9B=AE=E7=9B=AE?= =?UTF-8?q?=E5=BD=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- src/Example22.java | 2 - src/Example23.java | 2 - src/GetMax.java | 2 - src/{ => chapter2}/ClassScoreAnalyzer.java | 2 + src/{ => chapter2}/Department.java | 2 + src/{ => chapter2}/Example07.java | 2 + src/{ => chapter2}/Example08.java | 2 + src/{ => chapter2}/Example09.java | 2 + src/{ => chapter2}/Example10.java | 2 + src/{ => chapter2}/Example11.java | 2 + src/{ => chapter2}/Example12.java | 2 + src/{ => chapter2}/Example13.java | 2 + src/{ => chapter2}/Example14.java | 2 + src/{ => chapter2}/Example16.java | 4 +- src/{ => chapter2}/Example17.java | 2 + src/{ => chapter2}/Example19.java | 8 +- src/{ => chapter2}/Example20.java | 2 + src/{ => chapter2}/Example21.java | 2 + src/chapter2/Example22.java | 15 +++ src/chapter2/Example23.java | 14 +++ src/chapter2/GetMax.java | 7 ++ src/{ => chapter2}/SuperMarket.java | 11 +- src/chapter2/User.java | 122 +++++++++++++++++++++ src/chapter3/Example01.java | 37 +++++++ src/chapter3/Example05.java | 59 ++++++++++ src/chapter3/demo31/Book.java | 36 ++++++ src/chapter3/demo31/Order.java | 43 ++++++++ src/chapter3/demo31/OrderItem.java | 22 ++++ src/chapter3/demo31/PayBooks.java | 64 +++++++++++ 29 files changed, 457 insertions(+), 17 deletions(-) delete mode 100644 src/Example22.java delete mode 100644 src/Example23.java delete mode 100644 src/GetMax.java rename src/{ => chapter2}/ClassScoreAnalyzer.java (98%) rename src/{ => chapter2}/Department.java (98%) rename src/{ => chapter2}/Example07.java (91%) rename src/{ => chapter2}/Example08.java (93%) rename src/{ => chapter2}/Example09.java (96%) rename src/{ => chapter2}/Example10.java (91%) rename src/{ => chapter2}/Example11.java (97%) rename src/{ => chapter2}/Example12.java (94%) rename src/{ => chapter2}/Example13.java (91%) rename src/{ => chapter2}/Example14.java (91%) rename src/{ => chapter2}/Example16.java (83%) rename src/{ => chapter2}/Example17.java (93%) rename src/{ => chapter2}/Example19.java (75%) rename src/{ => chapter2}/Example20.java (93%) rename src/{ => chapter2}/Example21.java (97%) create mode 100644 src/chapter2/Example22.java create mode 100644 src/chapter2/Example23.java create mode 100644 src/chapter2/GetMax.java rename src/{ => chapter2}/SuperMarket.java (84%) create mode 100644 src/chapter2/User.java create mode 100644 src/chapter3/Example01.java create mode 100644 src/chapter3/Example05.java create mode 100644 src/chapter3/demo31/Book.java create mode 100644 src/chapter3/demo31/Order.java create mode 100644 src/chapter3/demo31/OrderItem.java create mode 100644 src/chapter3/demo31/PayBooks.java diff --git a/src/Example22.java b/src/Example22.java deleted file mode 100644 index 63f0ea9..0000000 --- a/src/Example22.java +++ /dev/null @@ -1,2 +0,0 @@ -package PACKAGE_NAME;public class Example22 { -} diff --git a/src/Example23.java b/src/Example23.java deleted file mode 100644 index 34faf54..0000000 --- a/src/Example23.java +++ /dev/null @@ -1,2 +0,0 @@ -package PACKAGE_NAME;public class Example23 { -} diff --git a/src/GetMax.java b/src/GetMax.java deleted file mode 100644 index adbf374..0000000 --- a/src/GetMax.java +++ /dev/null @@ -1,2 +0,0 @@ -package PACKAGE_NAME;public class GetMax { -} diff --git a/src/ClassScoreAnalyzer.java b/src/chapter2/ClassScoreAnalyzer.java similarity index 98% rename from src/ClassScoreAnalyzer.java rename to src/chapter2/ClassScoreAnalyzer.java index 122dda2..f20e6a4 100644 --- a/src/ClassScoreAnalyzer.java +++ b/src/chapter2/ClassScoreAnalyzer.java @@ -1,3 +1,5 @@ +package chapter2; + public class ClassScoreAnalyzer { public static void main(String[] args) { // 1. 创建并初始化数组 diff --git a/src/Department.java b/src/chapter2/Department.java similarity index 98% rename from src/Department.java rename to src/chapter2/Department.java index 8b768e2..54e3fb9 100644 --- a/src/Department.java +++ b/src/chapter2/Department.java @@ -1,3 +1,5 @@ +package chapter2; + import java.util.Scanner; public class Department { diff --git a/src/Example07.java b/src/chapter2/Example07.java similarity index 91% rename from src/Example07.java rename to src/chapter2/Example07.java index 10d829d..46b8ec4 100644 --- a/src/Example07.java +++ b/src/chapter2/Example07.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example07 { public static void main(String[] args) { int x = 5; diff --git a/src/Example08.java b/src/chapter2/Example08.java similarity index 93% rename from src/Example08.java rename to src/chapter2/Example08.java index 7e3adc7..96ba66f 100644 --- a/src/Example08.java +++ b/src/chapter2/Example08.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example08 { public static void main(String[] args) { int num = 20; diff --git a/src/Example09.java b/src/chapter2/Example09.java similarity index 96% rename from src/Example09.java rename to src/chapter2/Example09.java index 5f11856..099f3f4 100644 --- a/src/Example09.java +++ b/src/chapter2/Example09.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example09 { public static void main(String[] args) { int grade = 75; diff --git a/src/Example10.java b/src/chapter2/Example10.java similarity index 91% rename from src/Example10.java rename to src/chapter2/Example10.java index d983f9a..51ee0d5 100644 --- a/src/Example10.java +++ b/src/chapter2/Example10.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example10 { public static void main(String[] args) { int x = 0; diff --git a/src/Example11.java b/src/chapter2/Example11.java similarity index 97% rename from src/Example11.java rename to src/chapter2/Example11.java index a1e14f8..906eaaa 100644 --- a/src/Example11.java +++ b/src/chapter2/Example11.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example11 { public static void main(String[] args) { int week = 1; diff --git a/src/Example12.java b/src/chapter2/Example12.java similarity index 94% rename from src/Example12.java rename to src/chapter2/Example12.java index 284dd3c..9d791d3 100644 --- a/src/Example12.java +++ b/src/chapter2/Example12.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example12 { public static void main(String[] args) { int x = 5; // 定义变量x，初始值为1 diff --git a/src/Example13.java b/src/chapter2/Example13.java similarity index 91% rename from src/Example13.java rename to src/chapter2/Example13.java index 9cdfb68..b3908d2 100644 --- a/src/Example13.java +++ b/src/chapter2/Example13.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example13 { public static void main(String[] args) { int x = 5; diff --git a/src/Example14.java b/src/chapter2/Example14.java similarity index 91% rename from src/Example14.java rename to src/chapter2/Example14.java index 66155bc..07f030c 100644 --- a/src/Example14.java +++ b/src/chapter2/Example14.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example14 { public static void main(String[] args) { int sum = 0; diff --git a/src/Example16.java b/src/chapter2/Example16.java similarity index 83% rename from src/Example16.java rename to src/chapter2/Example16.java index ad27960..780db44 100644 --- a/src/Example16.java +++ b/src/chapter2/Example16.java @@ -1,10 +1,12 @@ +package chapter2; + public class Example16 { public static void main(String[] args) { int x = 1; while (x <= 4) { System.out.println("x = " + x); if (x == 3) { - break; + continue; } x ++; } diff --git a/src/Example17.java b/src/chapter2/Example17.java similarity index 93% rename from src/Example17.java rename to src/chapter2/Example17.java index 4fcbee7..a841d95 100644 --- a/src/Example17.java +++ b/src/chapter2/Example17.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example17 { public static void main(String[] args) { int x = 1; diff --git a/src/Example19.java b/src/chapter2/Example19.java similarity index 75% rename from src/Example19.java rename to src/chapter2/Example19.java index 4f4f74c..047ff4f 100644 --- a/src/Example19.java +++ b/src/chapter2/Example19.java @@ -1,6 +1,8 @@ +package chapter2; + public class Example19 { public static void main(String[] args) { - printRectangle(3, 40); + printRectangle(3, 5); } // 下面定义了一个打印矩形的方法，接收两个参数，其中height为高，width为宽 @@ -8,10 +10,8 @@ public class Example19 { // 下面是使用嵌套for循环实现*打印矩形 for (int i = 0; i < height; i++) { for (int j = 0; j < width; j++) { - System.out.print("*"); + } -// System.out.print("\n"); - System.out.println(); } } diff --git a/src/Example20.java b/src/chapter2/Example20.java similarity index 93% rename from src/Example20.java rename to src/chapter2/Example20.java index e154f06..bc9a9e5 100644 --- a/src/Example20.java +++ b/src/chapter2/Example20.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example20 { public static void main(String[] args) { int area = getArea(3, 5); diff --git a/src/Example21.java b/src/chapter2/Example21.java similarity index 97% rename from src/Example21.java rename to src/chapter2/Example21.java index bdcc6ee..c9669d7 100644 --- a/src/Example21.java +++ b/src/chapter2/Example21.java @@ -1,3 +1,5 @@ +package chapter2; + public class Example21 { public static void main(String[] args) { // 下面针对求和方法的调用 diff --git a/src/chapter2/Example22.java b/src/chapter2/Example22.java new file mode 100644 index 0000000..fd651ed --- /dev/null +++ b/src/chapter2/Example22.java @@ -0,0 +1,15 @@ +package chapter2; + +public class Example22 { + public static void main(String[] args) { + int[] arr; // 声明变量 + arr = new int[3]; // 创建数据对象 + + System.out.println("arr[0] = " + arr[0]); // 访问数组中的第一个元素 + System.out.println("arr[1] = " + arr[1]); // 访问数组中的第二个元素 + System.out.println("arr[2] = " + arr[2]); // 访问数组中的第三个元素 + + System.out.println("数组的长度是：" + arr.length); // 打印数组的长度 + + } +} diff --git a/src/chapter2/Example23.java b/src/chapter2/Example23.java new file mode 100644 index 0000000..e0688fa --- /dev/null +++ b/src/chapter2/Example23.java @@ -0,0 +1,14 @@ +package chapter2; + +public class Example23 { + public static void main(String[] args) { + int[] arr = new int[4]; // 定义可以存储4个元素的整数类型数组 + arr[0] = 1; // 为第1个元素赋值1 + arr[1] = 1; // 为第2个元素赋值2 + //依次打印数组中每个元素的值 + System.out.println("arr[0]: " + arr[0]); + System.out.println("arr[1]: " + arr[1]); + System.out.println("arr[2]: " + arr[2]); + System.out.println("arr[3]: " + arr[3]); + } +} diff --git a/src/chapter2/GetMax.java b/src/chapter2/GetMax.java new file mode 100644 index 0000000..06ee62a --- /dev/null +++ b/src/chapter2/GetMax.java @@ -0,0 +1,7 @@ +package chapter2; + +public class GetMax { + public static void main(String[] args) { + + } +} diff --git a/src/SuperMarket.java b/src/chapter2/SuperMarket.java similarity index 84% rename from src/SuperMarket.java rename to src/chapter2/SuperMarket.java index 2197180..b2c98c2 100644 --- a/src/SuperMarket.java +++ b/src/chapter2/SuperMarket.java @@ -1,3 +1,5 @@ +package chapter2; + import java.util.Scanner; public class SuperMarket { @@ -29,26 +31,23 @@ public class SuperMarket { int cupnumber = sc1.nextInt(); double cupnum = cupnumber * cup; System.out.println("你购买了水杯" + cupnumber + "个，需要花费" + cupnum + "元"); - System.out.println("需要继续购买请输入Y，否则输入N"); - continueShopping = sc1.next(); break; case 2: System.out.println("请输入你需要购买苹果的数量:"); int applenumber = sc1.nextInt(); double applenum = applenumber * apple; System.out.println("你购买了苹果" + applenumber + "斤，需要花费" + applenum + "元"); - System.out.println("需要继续购买请输入Y，否则输入N"); - continueShopping = sc1.next(); break; case 3: System.out.println("请输入你需要购买香蕉的数量:"); int banananumber = sc1.nextInt(); double banananum = banananumber * banana; System.out.println("你购买了香蕉" + banananumber + "斤，需要花费" + banananum + "元"); - System.out.println("需要继续购买请输入Y，否则输入N"); - continueShopping = sc1.next(); break; } + + System.out.println("需要继续购买请输入Y，否则输入N"); + continueShopping = sc1.next(); } System.out.println("期待您的下次光临！"); diff --git a/src/chapter2/User.java b/src/chapter2/User.java new file mode 100644 index 0000000..5b9ab3c --- /dev/null +++ b/src/chapter2/User.java @@ -0,0 +1,122 @@ +package chapter2; + +import java.util.Scanner; + +public class User { + // 存储用户名和密码 + // 两个数组前加上static属性，这样做是为了让本类都可以使用到这两个数组 + static String[] usernames = new String[10]; + static String[] passwords = new String[10]; + + static int count = 1; + + public static void main(String[] args) { + // 假设系统中已经有一个用户 + usernames[0] = "java"; + passwords[0] = "123456"; + + while (true) { + print(); + Scanner input = new Scanner(System.in); + System.out.println("请选择功能："); + int option = input.nextInt(); + switch (option) { + case 0: + System.exit(0); + case 1: + login(); + break; + case 2: + register(); + break; + case 3: + show(); + break; + default: + System.out.println("输入错误！"); + break; + } + } + } + + /* + * 登录功能，键盘输入用户名与密码 + * 使用for循环加if判断验证输入的用户名与密码是否正确 + */ + public static void login() { + Scanner input = new Scanner(System.in); + + System.out.println("请输入用户名："); + String username = input.next(); + + System.out.println("请输入密码："); + String password = input.next(); + + for (int i = 0; i < count; i++) { + if (username.equals(usernames[i]) && password.equals(passwords[i])) { + System.out.println("登录成功！"); + return; + } + } + + System.out.println("登录失败，请重新输入"); + } + + /* + * 注册功能 + * 定义一个boolean变量，使用for循序判断用户是否存在 + * 如果用户不存在，在数组中插入注册的账号密码时 + * 可能会有数组长度不够的情况，所以需要使用到 + * 增加数组的长度，这里调用增加数组长度的方法add()。 + */ + public static void register() { + Scanner input = new Scanner(System.in); + + System.out.println("请输入用户名："); + String username = input.next(); + + System.out.println("请输入密码："); + String password = input.next(); + + boolean flag = true; + for (int i = 0; i < count; i++) { + if (username.equals(usernames[i])) { + System.out.println("用户名已存在"); + flag = false; + } + } + + if (flag) { + if (count < usernames.length) { + count++; + usernames[count - 1] = username; + passwords[count - 1] = password; + System.out.println("注册成功！"); + } else { + System.out.println("数组空间不足！"); + } + + } + } + + /* + * 查看功能 + */ + public static void show() { + for (int i = 0; i < count; i++) { + System.out.println("用户名：" + usernames[i] + "，密码：" + passwords[i]); + } + } + + /* + * 打印功能菜单 + */ + public static void print() { + System.out.println("-----------------用户管理系统-------------------"); + System.out.println("1.登录功能"); + System.out.println("2.注册功能"); + System.out.println("3.查看"); + System.out.println("0.退出"); + System.out.println("-----------------用户管理系统-------------------"); + } +} diff --git a/src/chapter3/Example01.java b/src/chapter3/Example01.java new file mode 100644 index 0000000..4e52636 --- /dev/null +++ b/src/chapter3/Example01.java @@ -0,0 +1,37 @@ +package chapter3; + +class Student { + String name; + int age; + String sex; + + void read() { + System.out.println("大家好，我是" + name + "，我在看书！"); + } + + void introduce() { + System.out.println("大家好，我叫" + name + "，我今年" + age + "岁了，我是" + sex + "孩"); + } +} + +public class Example01 { + public static void main(String[] args) { + Student s1 = new Student(); + Student s2 = new Student(); + + s1.name = "小明"; + s1.sex = "男"; + s1.age = 20; + + + s2.name = "小红"; + s2.sex = "女"; + s2.age = 19; + + s1.read(); + s2.read(); + + s1.introduce(); + s2.introduce(); + } +} diff --git a/src/chapter3/Example05.java b/src/chapter3/Example05.java new file mode 100644 index 0000000..2ca9e79 --- /dev/null +++ b/src/chapter3/Example05.java @@ -0,0 +1,59 @@ +package chapter3; + +class Book { + int id; // 编号 + String name; // 书名 + +// public Book() { +// this.id = 0; +// this.name = "未命名"; +// System.out.println("初始化：无参构造被调用！"); +// } + + // 打印信息 + public void print() { + System.out.println("print函数 - ID：" + this.id + "，书名：" + this.name); + } + + // 获取书号 + public int getId() { + return id; + } + + // 设置书号 + public void setId(int id) { + this.id = id; + } + + // 获取书名 + public String getName() { + return name; + } + + // 设置书名 + public void setName(String name) { + this.name = name; + } + + public static void main(String[] args) { + Book[] books = new Book[10]; + + // 使用 setter 初始化 + books[0] = new Book(); + books[0].print(); + System.out.println("初始化：手动"); + books[0].setId(1); + books[0].setName("Java教程"); + books[0].print(); + + System.out.println("============"); + + // 直接访问属性进行初始化（注意访问控制） + books[1] = new Book(); + books[1].print(); + System.out.println("初始化：手动"); + books[1].id = 2; + books[1].name = "JSP教程"; + books[1].print(); + } +} diff --git a/src/chapter3/demo31/Book.java b/src/chapter3/demo31/Book.java new file mode 100644 index 0000000..292eecd --- /dev/null +++ b/src/chapter3/demo31/Book.java @@ -0,0 +1,36 @@ +package chapter3.demo31; + +public class Book { + private final int id; // 编号 + private final String name; // 书名 + private final double price; // 价格 + private final int storage; // 库存 + + // 有参构造 + public Book(int id, String name, double price, int storage) { + this.id = id; + this.name = name; + this.price = price; + this.storage = storage; + } + + // 获取书号 + public int getId() { + return id; + } + + // 获取书名 + public String getName() { + return name; + } + + // 获取价格 + public double getPrice() { + return price; + } + + // 获取库存 + public int getStorage() { + return storage; + } +} diff --git a/src/chapter3/demo31/Order.java b/src/chapter3/demo31/Order.java new file mode 100644 index 0000000..5e60f23 --- /dev/null +++ b/src/chapter3/demo31/Order.java @@ -0,0 +1,43 @@ +package chapter3.demo31; + +public class Order { + private final String orderId; + private final OrderItem[] items; + private double total; + + // 有参构造 + public Order(String orderId) { + this.orderId = orderId; + this.items = new OrderItem[3]; + } + + // 获取订单号 + public String getOrderId() { + return orderId; + } + + // 获取订单列表 + public OrderItem[] getItems() { + return items; + } + + // 获取订单总额 + public double getTotal() { + calTotal(); + return total; + } + + // 指定一个订单项 + public void setItem(OrderItem item, int i) { + this.items[i] = item; + } + + // 计算订单总额 + public void calTotal() { + double total = 0; + for (OrderItem item : items) { + total += item.getNum() * item.getBook().getPrice(); + } + this.total = total; + } +} diff --git a/src/chapter3/demo31/OrderItem.java b/src/chapter3/demo31/OrderItem.java new file mode 100644 index 0000000..519570e --- /dev/null +++ b/src/chapter3/demo31/OrderItem.java @@ -0,0 +1,22 @@ +package chapter3.demo31; + +public class OrderItem { + private final Book book; + private final int num; + + // 有参构造方法 + public OrderItem(Book book, int num) { + this.book = book; + this.num = num; + } + + // 获取图书对象 + public Book getBook() { + return book; + } + + // 获取订购图书数量 + public int getNum() { + return num; + } +} diff --git a/src/chapter3/demo31/PayBooks.java b/src/chapter3/demo31/PayBooks.java new file mode 100644 index 0000000..01f1e8d --- /dev/null +++ b/src/chapter3/demo31/PayBooks.java @@ -0,0 +1,64 @@ +package chapter3.demo31; + +import java.util.Scanner; + +public class PayBooks { + public static void main(String[] args) { + Book[] books = new Book[3]; + // 模拟从数据库中读取图书信息并输出 + outBooks(books); + // 顾客购买图书 + Order order = purchase(books); + // 输出订单信息 + outOrder(order); + } + + // 顾客购买图书 + public static Order purchase(Book[] books) { + Order order = new Order("00001"); + OrderItem item = null; + Scanner in = new Scanner(System.in); + + for (int i = 0; i < 3; i++) { + System.out.println("请输入图书编号选择图书："); + int cno = in.nextInt(); + System.out.println("请输入购买图书数量："); + int pnum = in.nextInt(); + item = new OrderItem(books[cno - 1], pnum); + order.setItem(item, i); + System.out.println("请继续购买图书。"); + } + in.close(); + return order; + } + + // 输出订单信息 + public static void outOrder(Order order) { + System.out.println("\n===================图书订单==================="); + System.out.println("图书订单号：" + order.getOrderId()); + System.out.println("图书名称\t购买数量\t图书单价"); + System.out.println("--------------------------------------"); + OrderItem[] items = order.getItems(); + for (OrderItem item : items) { + System.out.println( + item.getBook().getName() + "\t" + item.getNum() + "\t" + item.getBook().getPrice()); + } + System.out.println("---------------------------------------"); + System.out.println("订单总额：\t\t" + order.getTotal()); + } + + // 模拟从数据库中读取图书信息并输出 + public static void outBooks(Book[] books) { + books[0] = new Book(1, "Java教程", 30.6, 30); + books[1] = new Book(2, "JSP教程", 42.1, 40); + books[2] = new Book(3, "SSH架构", 47.3, 15); + System.out.println("===================图书列表==================="); + System.out.println("图书编号\t图书名称\t\t图书单价\t库存数量"); + System.out.println("---------------------------------------"); + for (int i = 0; i < books.length; i++) { + System.out.println( + i + 1 + "\t" + books[i].getName() + "\t" + books[i].getPrice() + "\t" + books[i].getStorage()); + } + System.out.println("---------------------------------------"); + } +}