StudentInformation.java

package exp3;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

class StudentInformationException extends Exception {

    StudentInformationException(String message) {
        super(message);
    }
}

class EmptyBuildIsNotAllowedException extends StudentInformationException {

    EmptyBuildIsNotAllowedException() {
        super("Empty build is not allowed.");
    }
}

public class StudentInformation {

    public record Detail(String name, String stuid, Gender gender, int[] birthdate) {

    }

    private static List<Detail> StudentInfo = new ArrayList<>(
            List.of(
                    new Detail("郑秀梅", "65385", Gender.FEMALE, new int[]{2004, 8, 11}),
                    new Detail("段莹", "76679", Gender.FEMALE, new int[]{2005, 5, 28}),
                    new Detail("毛桂香", "98372", Gender.FEMALE, new int[]{2003, 7, 15}),
                    new Detail("姜文", "45617", Gender.MALE, new int[]{2006, 6, 23}),
                    new Detail("许平", "78703", Gender.MALE, new int[]{2003, 8, 7}),
                    new Detail("贾桂荣", "14469", Gender.FEMALE, new int[]{2007, 3, 3}),
                    new Detail("王凤兰", "86713", Gender.FEMALE, new int[]{2004, 3, 4}),
                    new Detail("方亮", "85327", Gender.FEMALE, new int[]{2008, 3, 10}),
                    new Detail("杨瑞", "95331", Gender.MALE, new int[]{2007, 2, 24}),
                    new Detail("张霞", "36881", Gender.FEMALE, new int[]{2006, 5, 28})));

    public static void main(String[] args) {
        Student[] students = new Student[10];
        for (int i = 0; i < 10; i++) {
            try {
                students[i] = new Student();
            } catch (EmptyBuildIsNotAllowedException e) {
                students[i] = new Student(
                        StudentInformation.StudentInfo.get(i).name(),
                        StudentInformation.StudentInfo.get(i).stuid(),
                        StudentInformation.StudentInfo.get(i).gender(),
                        StudentInformation.StudentInfo.get(i).birthdate());
            }
        }
        System.out.println("当前共有 " + students.length + " 个学生，信息如下：");
        FileWriter f = null;
        try {
            f = new FileWriter("./StudentInformation.txt");
        } catch (IOException e) {
            System.out.println("无法写出到文件");
            System.exit(1);
        }
        for (Student student : students) {
            System.out.println("姓名：" + student.getName());
            System.out.println("学号：" + student.getStuid());
            System.out.println("性别：" + student.getGender());
            System.out.println("出生日期：" + String.format("%d-%02d-%02d", student.getBirthdate()[0],
                    student.getBirthdate()[1], student.getBirthdate()[2]));
            System.out.println();
            if (f != null) {
                try {
                    f.write("姓名：" + student.getName() + "\n");
                    f.write("学号：" + student.getStuid() + "\n");
                    f.write("性别：" + student.getGender() + "\n");
                    f.write("出生日期：" + String.format("%d-%02d-%02d", student.getBirthdate()[0],
                            student.getBirthdate()[1], student.getBirthdate()[2]) + "\n");
                    f.write("\n");
                } catch (IOException e) {
                    System.out.println("无法写出到文件");
                    System.exit(1);
                }
            }
        }
        if (f != null) {
            try {
                f.close();
            } catch (IOException e) {
                System.out.println("无法关闭文件");
                System.exit(1);
            }
        }

        // 从文件中读出学生信息
        try {
            FileReader fr = new FileReader("./StudentInformation.txt");
            BufferedReader br = new BufferedReader(fr);
            String line;
            System.out.println("从文件中读取的学生信息如下：");
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
            br.close();
            fr.close();
        } catch (IOException e) {
            System.out.println("无法读取文件");
            System.exit(1);
        }
    }
}

enum Gender {
    MALE, FEMALE;
}

class Student {

    private String name;
    private String stuid;
    private Gender gender;
    private int[] birthdate; // [year, month, day]

    Student() throws EmptyBuildIsNotAllowedException {
        throw new EmptyBuildIsNotAllowedException(); // 不允许空构造
    }

    Student(String name, String stuid, Gender gender, int[] birthdate) {
        this.name = name;
        this.stuid = stuid;
        this.gender = gender;
        this.birthdate = birthdate;
    }

    String getName() {
        return name;
    }

    String getStuid() {
        return stuid;
    }

    Gender getGender() {
        return gender;
    }

    int[] getBirthdate() {
        return birthdate;
    }
}