java 简单的学生信息管理系统(控制台版)

程序简介

本程序主要用于演示和管理学生信息，用于展示信息和初级教学。这种教学主要是为了让我对程序开发有一些逻辑的理解，初学者可以专注于它。

如遇不解可咨询，Email 864377400@qq.com

程序开始

1.定义学生实体类

package Student;  /**  * @Author xgp  * @Date 2022/7/22 10:04  * @PackageName:Student  * @ClassName: StudentEntity  * @Description: TODO  * @Version 1.0  */ public class StudentEntity {      private String id;     private String name;     private String age;     private String phone;      @Override     public String toString() {         return "StudentEntity{"                   "id='"   id   '\''                   ", name='"   name   '\''                   ", age='"   age   '\''                   ", phone='"   phone   '\''                   '}';     }      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 String getAge() {         return age;     }      public void setAge(String age) {         this.age = age;     }      public String getPhone() {         return phone;     }      public void setPhone(String phone) {         this.phone = phone;     } } 

2.在这里定义一个装载学生信息容器LIST

    static List<StudentEntity> list = new ArrayList<StudentEntity>();

3.定义学生信息添加方法，同时在添加方法中增加相同学号信息。

 public static void add() {         System.out.println("------------添加信息------------");         StudentEntity studentEntity = new StudentEntity();         System.out.print("学号：");         while (true) {             Scanner scanner = new Scanner(System.in);             String id = scanner.next();             long count = list.stream().filter(item -> item.getId().equals(id)).count();             if (count > 0) {                 System.out.print("学号不能重复，请重新输入：");             } else {                 studentEntity.setId(id);                 break;             }         }         System.out.print("姓名：");         Scanner scanner = new Scanner(System.in);         String name = scanner.next();         System.out.print("年龄：");          while(true){             scanner = new Scanner(System.in);             String age = scanner.next();             try {                 int i = Integer.parseInt(age);                 studentEntity.setAge(age);                 break;             }catch (Exception e){                 System.out.print("年龄非数，请重新输入：");             }         }         System.out.print("手机：");         scanner = new Scanner(System.in);         String phone = scanner.next();         studentEntity.setName(name);         studentEntity.setPhone(phone);         System.out.println(studentEntity);         list.add(studentEntity);         System.out.println("------------添加成功------------");     }

4.定义和修改学生信息方法。该方法用户输入学号，通过查询学号获取相应的学生信息，确保学生信息存在。如果不存在，则需要重新输入学号进行搜索，并添加可退出功能。输入-1时，退出编辑界面

 public static void edit() {         System.out.println("------------编辑信息------------");         System.out.print("输入要编辑的学号(-1退出):");         boolean flag = true;         while (flag) {             Scanner scanner = new Scanner(System.in);             String editId = scanner.next();             if ("-1".equals(editId)) {                 System.out.println("------------操作取消------------");                 break;             }             StudentEntity studentEntity = new StudentEntity();             int index = -1;             for (int i = 0; i < list.size(); i  ) {                 StudentEntity item = list.get(i);                 studentEntity.setId(item.getId());                 studentEntity.setName(item.getName());                 studentEntity.setAge(item.getAge());                 studentEntity.setPhone(item.getPhone());                 if (editId.equals(studentEntity.getId())) {                     index = i;                     break;                 }             }             if (index == -1) {                 System.out.println("输入学号不存在，请重新输入(-1退出)：");             } else {                 System.out.print("姓名("   studentEntity.getName()   ")：");                 scanner = new Scanner(System.in);                 String name = scanner.nextLine();                 if (name.length() > 0) {                     studentEntity.setName(name);                 }                 System.out.print("年龄("   studentEntity.getAge()   ")：");                 scanner = new Scanner(System.in);                 String age = scanner.nextLine();                 if (age.length() > 0) {                     studentEntity.setAge(age);                 }                 System.out.print("手机号("   studentEntity.getPhone()   ")：");                 scaner = new Scanner(System.in);
                String phone = scanner.nextLine();
                if (phone.length() > 0) {
                    studentEntity.setPhone(phone);
                }
                System.out.print("确认是否编辑(Y/N)：");
                while (true) {
                    scanner = new Scanner(System.in);
                    String status = scanner.next();
                    if ("N".equals(status)) {
                        System.out.println("------------操作取消------------");
                        flag = false;
                        break;
                    }else if("Y".equals(status)) {
                        System.out.println("------------修改成功------------");
                        list.set(index,studentEntity);
                        flag = false;
                        break;
                    }else {
                        System.out.print("输入错误，请重新输入，确认是否编辑(Y/N)：");
                    }
                }
            }
        }

    }

5. 学生信息删除功能，获取用户输入学号信息，同时监听是否输入为-1，如输入-1则退出当前操作，否则验证当前输入学号是否存在，存在则删除，不存在则通知用户重新输入或者退出，同时添加确认条件，当输入Y是，确认删除，输入N时，退出删除。

 public static void del() {
        System.out.println("------------删除信息------------");
        System.out.print("输入要删除的学号(-1退出)：");
        boolean flag = true;
        while (flag) {
            Scanner scanner = new Scanner(System.in);
            String delId = scanner.next();
            if ("-1".equals(delId)) {
                System.out.println("------------操作取消------------");
                break;
            }
            int index = -1;
            for (int i = 0; i < list.size(); i++) {
               StudentEntity item = list.get(i);
                if(delId.equals(item.getId())){
                    index = i;
                    break;
                }
            }
            if(index == -1){
                System.out.print("输入学号不存在，请重新输入要删除的学号(-1退出)：");
            }else {
                System.out.print("确认是否编辑(Y/N)：");
                while (true) {
                    scanner = new Scanner(System.in);
                    String status = scanner.next();
                    if ("N".equals(status)) {
                        System.out.println("------------操作取消------------");
                        flag = false;
                        break;
                    }else if("Y".equals(status)) {
                        System.out.println("------------删除成功------------");
                        list.remove(index);
                        flag = false;
                        break;
                    }else {
                        System.out.print("输入错误，请重新输入，确认是否编辑(Y/N)：");
                    }
                }
            }
        }
    }

6.学生信息查询方法，遍历数据进行呈现，保证数据呈现格式化 ，让显示有规律

 public static void list() {
        System.out.println("------------学生列表------------");
        System.out.print("序号\t\t\t学号\t\t\t姓名\t\t\t年龄\t\t\t手机");
        System.out.println();
        if (list.size() == 0) {
            System.out.println("------------暂时未有学生信息，请添加------------");
        }
        for (int i = 0; i < list.size(); i++) {
            StudentEntity item = list.get(i);
            System.out.printf("%-12s", (i + 1));
            System.out.printf("%-12s", item.getId());
            System.out.printf("%-12s", item.getName());
            System.out.printf("%-12s", item.getAge());
            System.out.printf("%-12s", item.getPhone());
            System.out.println();
        }
    }

7.学生年龄分布，获取到各个年龄段的学生个数。

public static void ageDistributed() {
        System.out.println("------------学生年龄分布------------");
        System.out.print("序号\t\t0-20\t20-40\t40-60\t60以上");
        System.out.println();
        if (list.size() == 0) {
            System.out.println("------------暂时未有学生信息，请添加------------");
        }else {
          long one = list.stream().filter(item ->
                          (Integer.parseInt(item.getAge()) >= 0 &&
                                  Integer.parseInt(item.getAge()) < 20)).count();
            long two = list.stream().filter(item ->
                    (Integer.parseInt(item.getAge()) >= 20 &&
                            Integer.parseInt(item.getAge()) < 40)).count();
            long three = list.stream().filter(item ->
                    (Integer.parseInt(item.getAge()) >= 40 &&
                            Integer.parseInt(item.getAge()) < 60)).count();
            long four = list.stream().filter(item ->
                    (Integer.parseInt(item.getAge()) >= 60 )).count();
            System.out.printf("%-8s", ( 1));
            System.out.printf("%-8s", one);
            System.out.printf("%-8s", two);
            System.out.printf("%-8s", three);
            System.out.printf("%-8s", four);
            System.out.println();
        }
    }

8.通过学生姓名查询学生信息

 public static void listByName() {
        System.out.println("------------学生查询------------");
        System.out.print("输入要查询学生的姓名(-1退出)：");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.next();
        if("-1".equals(name)){
            System.out.println("------------操作取消------------");
            return;
        }
        List<StudentEntity> entities = list.stream().filter(item -> item.getName().equals(name)).collect(Collectors.toList());
        getByName(name, entities);
    }

9.通过学生学号查询学生信息

  public static void listById() {
        System.out.println("------------学生查询------------");
        System.out.print("输入要查询学生的姓名(-1退出)：");
        Scanner scanner = new Scanner(System.in);
        String id = scanner.next();
        if("-1".equals(id)){
            System.out.println("------------操作取消------------");
            return;
        }
        List<StudentEntity> entities = list.stream().filter(item -> item.getId().equals(id)).collect(Collectors.toList());
        getByName(id, entities);
    }

10.主方法，进入方法

  public static void main(String[] args) {
        Boolean flag = true;
        while (flag) {
            System.out.println("------------学生信息管理系统------------");
            System.out.println();
            System.out.println("\t\t\t1.添加学生");
            System.out.println("\t\t\t2.修改学生");
            System.out.println("\t\t\t3.删除学生");
            System.out.println("\t\t\t4.学生列表");
            System.out.println("\t\t\t5.退出");
            System.out.println("\t\t\t6.学生年龄分布");
            System.out.println("\t\t\t7.学生姓名查找");
            System.out.println("\t\t\t8.学生学号查找");
            System.out.print("\t\t请选择(1-8)：");
            Scanner scanner = new Scanner(System.in);
            String status = scanner.next();
            switch (status) {
                case "1":
                    add();
                    break;
                case "2":
                    edit();
                    break;
                case "3":
                    del();
                    break;
                case "4":
                    list();
                    break;
                case "6":
                    ageDistributed();
                    break;
                case "7":
                    listByName();
                    break;
                case "8":
                    listById();
                    break;
                case "5":
                    System.out.println("------------系统已退出------------");
                    flag = false;
                    break;
                default:
                    System.out.println("输入参数错误，请输入1 - 5");
            }
        }
    }