Java练手小项目——学生管理系统

目录

学生类

 菜单

添加学生信息功能的实现

删除学生信息功能的实现

修改学生信息功能的实现

查询学生信息的实现

通过ID获得下标功能的实现

判断ID是否唯一功能的实现

---

学生类

package timberman666;

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;
    }

    /**
     * 获取
     * @return id
     */
    public String getId() {
        return id;
    }

    /**
     * 设置
     * @param id
     */
    public void setId(String id) {
        this.id = id;
    }

    /**
     * 获取
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     * @return age
     */
    public int getAge() {
        return age;
    }

    /**
     * 设置
     * @param age
     */
    public void setAge(int age) {
        this.age = age;
    }

    /**
     * 获取
     * @return address
     */
    public String getAddress() {
        return address;
    }

    /**
     * 设置
     * @param address
     */
    public void setAddress(String address) {
        this.address = address;
    }

    public String toString() {
        return "Student{id = " + id + ", name = " + name + ", age = " + age + ", address = " + address + "}";
    }
}

 菜单

 loop:while (true) {
            System.out.println("Welcome to the timberman's Student Management System");
            System.out.println("1:Add");
            System.out.println("2:Delete");
            System.out.println("3:Modify");
            System.out.println("4:Query");
            System.out.println("5:Quit");
            System.out.println("Please enter your choice");
            Scanner sc=new Scanner(System.in);
            String choose= sc.next();
            switch (choose)
            {
                case"1"-> addStudent(list);
                case"2"-> deleteStudent(list);
                case"3"-> modifyStudent(list);
                case"4"-> queryStudent(list);
                case"5"-> {
                    System.out.println("Quit");
                    break loop;
                }
                default -> System.out.println("There is no such option");
            }
        }

添加学生信息功能的实现

    //add student
    public static void addStudent(ArrayList list) {
        System.out.println("Add a student");
        Student s= new Student();
        Scanner sc=new Scanner(System.in);

        String id=null;
        while (true) {
            System.out.println("Please enter the student's id");
            id=sc.next();
            boolean flag=contains(list,id);
            if(flag){
                System.out.println("The ID already exists, please re-enter it");
            }
            else{
                s.setId(id);
                break;
            }

        }

        System.out.println("Please enter the student's name");
        String name=sc.next();
        s.setName(name);

        System.out.println("Please enter the student's age");
        int age= sc.nextInt();
        s.setAge(age);

        System.out.println("Please enter the student's address");
        String address = sc.next();
        s.setAddress(address);

        list.add(s);

        System.out.println("Student information added successfully");
    }

删除学生信息功能的实现

    //delete student
    public static void deleteStudent(ArrayList list) {
        System.out.println("Delete a student");
        Scanner sc=new Scanner(System.in);
        String id=sc.next();
        int index=getIndex(list,id);
        if(index>=0){
            list.remove(index);
        }
        else{
            System.out.println("id does not exist, deletion failed");
        }

    }

修改学生信息功能的实现

    //modify student
    public static void modifyStudent(ArrayList list) {
        System.out.println("Modify a student");
        Scanner sc=new Scanner(System.in);
        String id=sc.next();
        int index=getIndex(list,id);
        if(index==-1){
            System.out.println("The ID to be modified does not exist " +id+ " please re-enter it");
            return;
        }
        Student stu=list.get(index);
        System.out.println("Please enter the name of the student you want to modify");
        String newName= sc.next();
        stu.setName(newName);

        System.out.println("Please enter the age of the student you want to modify");
        int newAge= sc.nextInt();
        stu.setAge(newAge);

        System.out.println("Please enter the address of the student you want to modify");
        String newAddress= sc.next();
        stu.setAddress(newAddress);

        System.out.println("The student's information was modified successfully");
    }

查询学生信息的实现

 //query student
    public static void queryStudent(ArrayList list) {
        System.out.println("Query a student");
        if(list.size()==0)
        {
            System.out.println("There is currently no student information, please add it and inquire");
            return;
        }
        System.out.println("id\t\tname\tage\taddress");
        for (int i = 0; i < list.size() ; i++) {
            Student stu=list.get(i);
            System.out.println(stu.getId()+"\t"+"\t"+stu.getName()+"\t"+stu.getAge()+"\t"+stu.getAddress());

        }

    }

通过ID获得下标功能的实现

    //Get the index by id
    public static int getIndex(ArrayList list,String id) {
        for (int i = 0; i < list.size(); i++) {
            Student stu=list.get(i);
            String sid= stu.getId();
            if(sid.equals(id)) {
                return i;
            }
        }
        return -1;
    }

判断ID是否唯一功能的实现

    //Determine whether the id exists in the collection
    public static boolean contains(ArrayList list,String id) {
        for (int i = 0; i < list.size(); i++) {
            Student s=list.get(i);
            String sid=s.getId();
            if(sid.equals(id)){
                return true;
            }
        }
        return false;
    }