Java学习笔记（10）

学生管理系统项目

package exercise;

import java.util.ArrayList;
import java.util.Scanner;

public class StudentProgramme {
    public static void main(String[] args) {
        ArrayList<Student> studentArrayList = new ArrayList<>();
        Student newStudent = new Student("001", "test", 1, "foshan");
        studentArrayList.add(newStudent);

        Scanner sc = new Scanner(System.in);

        while (true) {
            System.out.println("-------------欢迎来到学生管理系统----------------");
            System.out.println("1：添加学生");
            System.out.println("2：删除学生");
            System.out.println("3：修改学生");
            System.out.println("4：查询学生");
            System.out.println("5：退出");
            System.out.println("请输入您的选择:");

            int choose = sc.nextInt();
            switch (choose) {
                case 1 -> addStudent(studentArrayList);
                case 2 -> delStudent(studentArrayList);
                case 3 -> changeStudent(studentArrayList);
                case 4 -> checkStudent(studentArrayList);
                case 5 -> System.exit(0);
                default -> System.out.println("没有这个选择！");
            }
        }


    }

    public static void addStudent(ArrayList<Student> studentArrayList) {
        Scanner sc = new Scanner(System.in);
        Student newStudent = new Student();

        String id = "";
        while (true) {
            System.out.println("请输入学生id：");
            id = sc.next();
            if (contains(studentArrayList, id)) {
                System.out.println("输入的学生id已存在，请重新输入!");
            } else {
                newStudent.setId(id);
                break;
            }
        }

        System.out.println("请输入学生姓名：");
        String name = sc.next();
        newStudent.setName(name);

        System.out.println("请输入学生年龄：");
        int age = sc.nextInt();
        newStudent.setAge(age);

        System.out.println("请输入学生住址：");
        String address = sc.next();
        newStudent.setAddress(address);

        studentArrayList.add(newStudent);
        System.out.println("添加成功！");

    }


    public static void checkStudent(ArrayList<Student> studentArrayList) {
        if (studentArrayList.size() == 0) {
            System.out.println("当前无学生信息，请添加后再查询!");
        } else {
            System.out.println("id\t\t" + "姓名\t\t" + "年龄\t\t" + "家庭住址");
            for (Student student : studentArrayList) {
                System.out.println(student.getId() + "\t\t" + student.getName() + "\t" + student.getAge() + "\t\t" + student.getAddress());
            }
        }
    }

    public static void delStudent(ArrayList<Student> studentArrayList) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入删除的学生id：");
        String delId = sc.next();

        int index = getIndex(studentArrayList, delId);
        if (index >= 0) {
            studentArrayList.remove(index);
            System.out.println("删除成功！");
        } else {
            System.out.println("删除的学生id不存在！");
        }
    }

    public static void changeStudent(ArrayList<Student> studentArrayList) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入修改的学生id：");
        String changeId = sc.next();

        int index = getIndex(studentArrayList, changeId);
        if (index >= 0) {
            System.out.println("请输入修改学生的姓名：");
            String changeName = sc.next();
            studentArrayList.get(index).setName(changeName);

            System.out.println("请输入修改学生的年龄：");
            int changeAge = sc.nextInt();
            studentArrayList.get(index).setAge(changeAge);

            System.out.println("请输入修改学生的家庭住址：");
            String changeAddress = sc.next();
            studentArrayList.get(index).setAddress(changeAddress);

            System.out.println("修改成功！");

        } else {
            System.out.println("修改的学生id不存在！");
        }
    }

    public static boolean contains(ArrayList<Student> studentArrayList, String id) {
        return getIndex(studentArrayList, id) >= 0;
    }

    public static int getIndex(ArrayList<Student> studentArrayList, String id) {
        for (int i = 0; i < studentArrayList.size(); i++) {
            if (studentArrayList.get(i).getId().equals(id)) {
                return i;
            }
        }
        return -1;
    }
}

package exercise;

public class Student {
    private String id;
    private String name;
    private int age;
    private String address;

    public Student() {
    }

    public Student(String id, String name, int age, String address) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.address = address;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }


}

用户名和密码校验

package exercise;

import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class UserProgramme {
    public static void main(String[] args) {
        ArrayList<User> list = new ArrayList<>();
        User newUser = new User("001abc", "123456", "123456789012345678", "12345678901");
        list.add(newUser);

        Scanner sc = new Scanner(System.in);

        while (true) {
            System.out.println("-------------欢迎来到学生管理系统----------------");
            System.out.println("1：登录");
            System.out.println("2：注册");
            System.out.println("3：忘记密码");
            System.out.println("4：退出");
            System.out.println("请输入您的选择:");

            int choose = sc.nextInt();
            switch (choose) {
                case 1 -> longin(list);
                case 2 -> register(list);
                case 3 -> forgetPassword(list);
                case 4 -> System.exit(0);
                default -> System.out.println("没有这个选择！");
            }
        }


    }

    public static void longin(ArrayList<User> list) {
        //键盘录入用户名
        Scanner sc = new Scanner(System.in);
        System.out.println("输入用户名：");
        String userName = sc.next();

        //用户名如果未注册，直接结束方法，并提示：用户名未注册，请先注册
        int index = getIndex(list, userName);
        if (index == -1) {
            System.out.println("用户名未注册，请先注册!");
            return;
        }

        //键盘录入密码
        System.out.println("输入密码：");
        String password = sc.next();

        //键盘录入验证码
        loop3:
        while (true) {
            String rightNum = getCheckNum();
            System.out.println("验证码：" + rightNum);
            System.out.println("输入验证码：");
            String checkNum = sc.next();
            if (rightNum.equalsIgnoreCase(checkNum)) {
                System.out.println("验证码正确！");
                for (int i = 0; i < 3; i++) {
                    if (password.equals(list.get(index).getPassword())) {
                        System.out.println("登录成功！");
                        StudentProgramme ss = new StudentProgramme();
                        ss.startStudentProgramme();
                        break loop3;
                    } else {
                        if (i == 2) {
                            System.out.println("密码输错3次,登录失败！");
                            break loop3;
                        }
                        System.out.println("重新输入密码,还有" + (2 - i) + "次机会");
                        password = sc.next();
                    }
                }
                //密码输错3次，回到菜单
                break;
            } else {
                System.out.println("验证码不对！");
            }
        }

    }

    public static void forgetPassword(ArrayList<User> list) {
        //键盘录入用户名，判断当前用户名是否存在
        Scanner sc = new Scanner(System.in);
        System.out.println("输入用户名：");
        String userName = sc.next();

        //如不存在，直接结束方法，并提示：未注册
        int index = getIndex(list, userName);
        if (index == -1) {
            System.out.println("未注册！");
            return;
        }

        //键盘录入身份证号码和手机号码
        System.out.println("输入身份证号码：");
        String id = sc.next();
        System.out.println("输入手机号：");
        String phone = sc.next();

        //判断当前用户的身份证号码和手机号码是否一致
        boolean flag1 = list.get(index).getId().equals(id);
        boolean flag2 = list.get(index).getPhoneNum().equals(phone);

        if (!(flag1 && flag2)) {
            System.out.println("账号信息不匹配，修改失败!");
            return;
        }

        System.out.println("输入密码：");
        String newPassword = sc.next();
        list.get(index).setPassword(newPassword);
        System.out.println("密码修改成功！");

    }

    public static void register(ArrayList<User> list) {
        User newUser = new User();
        Scanner sc = new Scanner(System.in);
        System.out.println("输入用户名：");
        String newUserName = sc.next();


        //用户名长度必须在3~15位之间
        int len = newUserName.length();
        if (len < 3 || len > 15) {
            System.out.println("用户名长度不符合要求！");
            return;
        }

        //只能是字母加数字的组合
        char[] charArray = newUserName.toCharArray();
        int countAlpha = 0;
        for (char c : charArray) {
            if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c >= '0' && c <= '9') {
                if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z') {
                    countAlpha++;
                    break;
                }
            } else {
                System.out.println("用户名有字母和数字以外，不符合要求！");
                return;
            }
        }

        //不能是纯数字
        if (countAlpha == 0) {
            System.out.println("用户名是纯数字，不符合要求！");
            return;
        }

        //用户名唯一
        if (contains(list, newUserName)) {
            System.out.println("用户名已存在！");
            return;
        }

        newUser.setUserName(newUserName);

        //密码键盘输入两次，两次一致才可以进行注册。
        while (true) {
            System.out.println("输入密码：");
            String newPassword = sc.next();
            System.out.println("再次输入密码：");
            String checkPassword = sc.next();

            boolean equals = newPassword.equals(checkPassword);
            if (equals) {
                newUser.setPassword(newPassword);
                break;
            } else {
                System.out.println("两次输入密码不同，重新输入！");
            }
        }

        //身份证号码需要验证。
        loop1:
        while (true) {
            System.out.println("输入身份证号码：");
            String id = sc.next();

            //长度为18位
            if (id.length() != 18) {
                System.out.println("输入身份证号码的长度不对！");
                continue;
            }

            //不能以0为开头
            if (id.charAt(0) == 0) {
                System.out.println("输入身份证号码第一位不对！");
                continue;
            }

            //前17位，必须都是数字
            char[] charArrayId = id.toCharArray();
            for (int i = 0; i < charArrayId.length - 1; i++) {
                if (charArrayId[i] < '0' || charArrayId[i] > '9') {
                    System.out.println("输入身份证号码前17位不全是数字！");
                    continue loop1;
                }
            }

            //最为一位可以是数字，也可以是大写X或小写x
            char lastChar = id.charAt(id.length() - 1);
            boolean flag = ((lastChar >= '0' && lastChar <= '9') || lastChar == 'X' || lastChar == 'x');
            if (!flag) {
                System.out.println("输入身份证最后一位不是数字或X或x！");
                continue;
            }

            newUser.setId(id);
            break;
        }

        //手机号验证。
        loop2:
        while (true) {
            System.out.println("输入手机号码：");
            String phone = sc.next();
            //长度为11位
            if (phone.length() != 11) {
                System.out.println("手机号长度不对！");
                continue;
            }
            //不能以0为开头
            if (phone.charAt(0) == 0) {
                System.out.println("手机号第一位不对！");
                continue;
            }

            //必须都是数字
            char[] charArrayPhone = phone.toCharArray();
            for (int i = 0; i < charArrayPhone.length; i++) {
                if (charArrayPhone[i] < '0' || charArrayPhone[i] > '9') {
                    System.out.println("输入身份证号码不全是数字！");
                    continue loop2;
                }
            }

            newUser.setPhoneNum(phone);
            break;
        }


        System.out.println("注册成功！");
    }


    public static boolean contains(ArrayList<User> list, String userName) {
        return getIndex(list, userName) >= 0;
    }

    public static int getIndex(ArrayList<User> list, String userName) {
        for (int i = 0; i < list.size(); i++) {
            if (list.get(i).getUserName().equals(userName)) {
                return i;
            }
        }
        return -1;
    }

    public static String getCheckNum() {
        char[] resultChar = new char[5];

        char[] arr = new char[52];
        for (int i = 0; i < 26; i++) {
            arr[i] = (char) ('a' + i);
            arr[i + 26] = (char) ('A' + i);
        }

        Random r = new Random();
        for (int i = 0; i < 4; i++) {
            int index = r.nextInt(52);
            resultChar[i] = arr[index];
        }

        int number = r.nextInt(10);
        resultChar[4] = (char) (number + 48);

        int index = r.nextInt(5);
        char temp = resultChar[4];
        resultChar[4] = resultChar[index];
        resultChar[index] = temp;

        String resultStr = new String(resultChar);

        return resultStr;
    }

    public static boolean isRightCheckNum(String rightNum, String checkNum) {
        for (int i = 0; i < rightNum.length(); i++) {
            if (rightNum.charAt(i) == checkNum.charAt(i) || rightNum.charAt(i) == (checkNum.charAt(i) + 32)
                    || rightNum.charAt(i) == (checkNum.charAt(i) - 32)) {
                continue;
            } else return false;
        }
        return true;

    }
}

package exercise;

public class User {
    private String userName;
    private String password;
    private String id;
    private String phoneNum;

    public User() {
    }

    public User(String userName, String password, String id, String phoneNum) {
        this.userName = userName;
        this.password = password;
        this.id = id;
        this.phoneNum = phoneNum;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getPhoneNum() {
        return phoneNum;
    }

    public void setPhoneNum(String phoneNum) {
        this.phoneNum = phoneNum;
    }
}