java学习笔记（10-学生管理系统练习）

1.简单学生管理系统练习

说明：键盘录入学生信息，实现学生信息的增删改

package com.daigua10;

import java.util.Scanner;
import java.io.BufferedWriter;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;

/*
 * 学生管理系统
 * */
public class StudentManagerSystem {
    public static void main(String[] args) throws IOException {
        while(true) {
            ArrayList<Student> array = new ArrayList<Student>();
            int choice = printer();
            switch (choice) {
            case 1:
                // 展示所有学生
                showStudentList(array);
                break;
            case 2:
                // 添加学生
                addStudent(array);
                break;
            case 3:
                // 删除学生
                deleteStudent(array);
                break;
            case 4:
                // 修改学生
                // 待续
                break;
            case 5:
                System.out.println("已退出学生管理系统！");
                break;
            default:
                break;
            }
            if(choice==5) {
                break;
            }
        }

    }

    public static void showStudentList(ArrayList<Student> array) throws IOException {
        // 从文件读取所有学生信息并显示出来
        readData(array);

        System.out.println("学号	" + "姓名	" + "年龄	" + "住址");
//      System.out.println(array);
        for (int i = 0; i < array.size(); i++) {
            Student temp_stu = array.get(i);
            System.out.println(temp_stu.getId() + '	' + temp_stu.getName() + '	' + temp_stu.getAge() + '	'
                    + temp_stu.getAddress());
        }

    }

    public static void addStudent(ArrayList<Student> array) throws IOException {
        readData(array);
        // 添加学生
        Scanner sc = new Scanner(System.in);

        System.out.println("请输入学号:");
        String id = sc.nextLine();
        System.out.println("请输入姓名:");
        String name = sc.nextLine();
        System.out.println("请输入年龄:");
        String age = sc.nextLine();
        System.out.println("请输入住址:");
        String address = sc.nextLine();

        Student stu = new Student(age, name, id, address);
        array.add(stu);
        // 写入文件
        writeData(array);
        System.out.println("添加成功！");

    }
    
    public static void deleteStudent(ArrayList<Student> arrayListStudent) throws IOException{
        // 更新下这个集合信息
        Scanner sc = new Scanner(System.in);
        Student temp_u = null;
        readData(arrayListStudent);
        System.out.println("请输入要删除的学生id:");
        String id = sc.nextLine();

        for (int i = 0; i < arrayListStudent.size(); i++) {
            String cur_id = arrayListStudent.get(i).getId();
            System.out.println("cur_id:"+cur_id);
            System.out.println("id:"+id);
            if(cur_id.equals(id)==true) {
                temp_u = arrayListStudent.get(i);
                System.out.println(temp_u);
                break;
            }
        }
        arrayListStudent.remove(temp_u);
        writeData(arrayListStudent);
    }

    public static void readData(ArrayList<Student> arrayListStudent) throws IOException {
        // 读取文件信息的方法
        BufferedReader br = new BufferedReader(new FileReader("./src/com/daigua10/student.txt"));
        String line;
        while ((line = br.readLine()) != null) {
            String[] cur_stu = line.split(",");
            Student temp_stu = new Student(cur_stu[2], cur_stu[1], cur_stu[0], cur_stu[3]);
            arrayListStudent.add(temp_stu);
        }
        br.close();
    }

    public static void writeData(ArrayList<Student> arrayListStudent) throws IOException {
        // 写入文件的方法
        BufferedWriter bw = new BufferedWriter(new FileWriter("./src/com/daigua10/student.txt"));
        for (int i = 0; i < arrayListStudent.size(); i++) {
            Student cur_stu = arrayListStudent.get(i);
            String temp_data = cur_stu.getId() + "," + cur_stu.getName() + "," + cur_stu.getAge() + ","
                    + cur_stu.getAddress();
            bw.write(temp_data);
            bw.newLine();
            bw.flush();
        }
        bw.close();
    }

    // 打印器
    public static int printer() {
        System.out.println("--------欢迎来到学生管理系统--------");
        System.out.println("1 查看所有学生");
        System.out.println("2 添加学生");
        System.out.println("3 删除学生");
        System.out.println("4 修改学生");
        System.out.println("5 退出");
        System.out.print("请输入你的选择:");
        Scanner sc = new Scanner(System.in);
        int choice = sc.nextInt();
//      System.out.println(choice);
        return choice;
    }

}