By GokiSoft.com| 15:39 10/07/2023|
Java Advanced

Chương trình quản lý sinh viên bằng HashMap - Java Advanced BT1058

1. Tạo 1 lớp sinh viên gồm các thuộc tính (RollNo, Name, Sex, Age, Email, Address).

Tạo hàm tạo không đối và hàm tạo có đầy đủ tham số.

2. Tạo một HashMap quản lý danh sách sinh viên, dùng rollNo là key cho HashMap

3. Xây dựng menu chương trình

- Nhập N sinh viên

- In thông tin sv

- Tìm kiếm sinh viên (Yêu cầu nhập RollNo và hiển thị thông tin sv đó)

Liên kết rút gọn:

https://gokisoft.com/1058

Bình luận

avatar
Phạm Dương Minh An [java2_online]
2022-03-25 06:23:38
//Entitty
public class Student {
    private String rollNo;
    private String name;
    private String age;
    private String email;
    private String address;

    public Student() {
    }

    public Student(String rollNo, String name, String age, String email, String address) {
        this.rollNo = rollNo;
        this.name = name;
        this.age = age;
        this.email = email;
        this.address = address;
    }

    public String getRollNo() {
        return rollNo;
    }

    public void setRollNo(String rollNo) {
        this.rollNo = rollNo;
    }

    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 getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAddress() {
        return address;
    }

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

    public void displayInfo() {
        System.out.println(this);
    }

    @Override
    public String toString() {
        return "Student [address=" + address + ", age=" + age + ", email=" + email + ", name=" + name + ", rollNo="
                + rollNo + "]";
    }

}

// Controller
import java.util.HashMap;
import java.util.Map;

public class StudentManagement {
    private Map<String, Student> studentList = new HashMap<String, Student>();

    public void addStudent(Student student) {
        studentList.put(student.getRollNo(), student);
    }  

    public Student searchStudentByRollNo(String rollNo) {
        return this.studentList.get(rollNo);
    }

    public boolean showAllStudent() {
        if(studentList.size() != 0) {
            studentList.forEach((rollNo, student) -> student.displayInfo());
            return true;
        }
        return false;
    }
}


//Main App

import java.util.Scanner;

public class App {
    static Scanner scanner = new Scanner(System.in);
    static StudentManagement studentManagement = new StudentManagement();

    public static void main(String[] args) throws Exception {
        int choose;
        do {
            showMenu();
            System.out.print("Enter your choice: ");
            choose = Integer.parseInt(scanner.nextLine());

            switch (choose) {
                case 1:
                    System.out.print("Enter the number of students you want to add: ");
                    int quantity = Integer.parseInt(scanner.nextLine());
                    addStudent(quantity);
                    break;
                case 2:
                    System.out.println("Show all student");
                    if (studentManagement.showAllStudent()) {
                        System.out.println("Show all student successfully");
                    } else {
                        System.out.println("No student in the list");
                    }
                    break;
                case 3:
                    System.out.print("Enter the roll no: ");
                    String rollNo = scanner.nextLine();
                    Student std = searchStudent(rollNo);
                    if (std != null) {
                        System.out.println("Search successfully !!");
                        std.displayInfo();
                    } else {
                        System.out.println("Not found!");
                    }
                    break;

                case 4:
                    System.out.println("Exit");
                    break;
                default:
                    System.out.println("Invalid choice");
                    break;
            }
        } while (choose != 4);
    }

    public static void showMenu() {
        System.out.println("1. Add Student");
        System.out.println("2. Show All Student");
        System.out.println("3. Search student by roll no");
        System.out.println("4. Exit");
    }

    public static void addStudent(int quantityStudent) {
        for (int i = 0; i < quantityStudent; ++i) {
            System.out.print("Enter roll no: ");
            String rollNo = scanner.nextLine();
            System.out.print("Enter name: ");
            String name = scanner.nextLine();
            System.out.print("Enter age: ");
            String age = scanner.nextLine();
            System.out.print("Enter email: ");
            String email = scanner.nextLine();
            System.out.print("Enter address: ");
            String address = scanner.nextLine();
            Student student = new Student(rollNo, name, age, email, address);
            studentManagement.addStudent(student);
        }
    }

    public static Student searchStudent(String rollNo) {
        return studentManagement.searchStudentByRollNo(rollNo);
    }
}





avatar
Nguyễn Hùng Anh [community,C2009G]
2021-09-04 05:01:43


#Main.java


import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
    public static void main(String [] args) {
//        System.out.println("haha");
        Scanner scanner = new Scanner(System.in);
        StudentController studentController = new StudentController();
        int c;
        do {
            System.out.println("\n\t\t-----------------------------------------");
            System.out.println("\n\t\t|0.Thoat ung dung.\t\t\t\t\t\t|");
            System.out.println("\n\t\t|1.Nhap thong tin sinh vien.\t\t\t|");
            System.out.println("\n\t\t|2.Hien thi thong tin sinh vien.\t\t|");
            System.out.println("\n\t\t|3.Tim kien sinh vien theo roll number. |");
            System.out.println("\nLua chon cua ban: ");
            c = scanner.nextInt();
            switch (c)
            {
                case 1:
                    studentController.insert();
                    break;
                case 2:
                    studentController.display();
                    break;
                case 3:
                    studentController.findByRollNo();
                    break;
                default:
                    break;
            }
        } while (c != 0);
    }
}


#Student.java


import java.util.Scanner;

public class Student {
    public String rollNo;
    public String name;
    public String sex;
    public Integer age;
    public String email;
    public String address;

    Scanner scanner = new Scanner(System.in);

    public Student() {
    }

    public Student(String rollNo, String name, String sex, Integer age, String email, String address) {
        this.rollNo = rollNo;
        this.name = name;
        this.sex = sex;
        this.age = age;
        this.email = email;
        this.address = address;
    }

    public String getRollNo() {
        return rollNo;
    }

    public void setRollNo(String rollNo) {
        this.rollNo = rollNo;
    }

    public String getName() {
        return name;
    }

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

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return age;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAddress() {
        return address;
    }

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

    @Override
    public String toString() {
        return String.format("Student %s\nName: %s\nSex: %s\nAge: %d\nEmail: %s\nAddress: %s",
                this.rollNo, this.name, this.sex, this.age, this.email, this.address);
    }

    public void input(){
        System.out.println("Enter student's roll number: ");
        rollNo = scanner.next();
        System.out.println("Enter student's name: ");
        name = scanner.next();
        System.out.println("Enter student's sex: ");
        sex = scanner.next();
        System.out.println("Enter student's age: ");
        age = scanner.nextInt();
        System.out.println("Enter student's email: ");
        email = scanner.next();
        System.out.println("Enter student's address: ");
        address = scanner.next();
    }
}


#StudentController.java


import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class StudentController {
    public Integer maxSize = 100;
    public Map<String, Student> map = new HashMap<>();
    public void insert() {
        Student student = new Student();
        student.input();
        if (map.size() < maxSize) {
            map.put(student.getRollNo(), student);
        } else {
            System.err.println("List is full, cannot update!");
        }
    }
    public void display() {
        for (Map.Entry<String, Student> entry: map.entrySet()){
            Student std = entry.getValue();
            System.out.println(std);
        }
    }

    public void findByRollNo() {
        String r;
        System.out.println("Nhap roll number: ");
        r = (new Scanner(System.in)).next();
        if (map.containsKey(r)) {
            Student std = map.get(r);
            System.out.println(std);
        }

    }

}


avatar
Hieu Ngo [community,C2009G]
2021-09-04 04:08:21


#Main.java


import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
    public static void main(String [] args) {

        Map<String, Student> studentMap = new HashMap<>();
        int x;
        do {
            System.out.println("Enter your choice");
            System.out.println("1.Input N students");
            System.out.println("2.Display information students");
            System.out.println("3.Find students by roll");
            System.out.println("4.Exit");
            System.out.println("Your choice:");
            x = (new Scanner(System.in)).nextInt();
            switch (x) {
                case 1: {
                    System.out.println("Enter number of students");
                    int n = (new Scanner(System.in)).nextInt();
                    for(int i=0; i< n ;i++) {
                        Student student = new Student();
                        student.input();
                        studentMap.put(student.getRollNo(), student);
                    }
                    break;
                }
                case 2: {
                    for(Map.Entry<String,Student> entry : studentMap.entrySet()) {
                        System.out.println(entry.toString());
                    }
                    break;
                }
                case 3: {
                    System.out.println("Enter roll u want search");
                    String searching = (new Scanner(System.in)).nextLine();
                    if(studentMap.containsKey(searching)) {
                        Student std = studentMap.get(searching);
                        System.out.println(std.toString());
                    }
                    break;
                }
                case 4: {
                    return ;
                }
            }
        } while (x>=1 && x<=4);
    }
}


#Student.java


import java.util.Scanner;

public class Student {
    private String rollNo, Name, Sex, Email, Address;
    private Integer Age;

    public Student() {
    }

    public Student(String rollNo, String name, String sex, String email, String address, Integer age) {
        this.rollNo = rollNo;
        Name = name;
        Sex = sex;
        Email = email;
        Address = address;
        Age = age;
    }

    public String getRollNo() {
        return rollNo;
    }

    public void setRollNo(String rollNo) {
        this.rollNo = rollNo;
    }

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }

    public String getSex() {
        return Sex;
    }

    public void setSex(String sex) {
        Sex = sex;
    }

    public String getEmail() {
        return Email;
    }

    public void setEmail(String email) {
        Email = email;
    }

    public String getAddress() {
        return Address;
    }

    public void setAddress(String address) {
        Address = address;
    }

    public Integer getAge() {
        return Age;
    }

    public void setAge(Integer age) {
        Age = age;
    }
    public Scanner getScanner() {
        return new Scanner(System.in);
    }

    public void input() {
        System.out.println("Enter roll");
        this.rollNo = getScanner().nextLine();
        System.out.println("Enter Name");
        this.Name = getScanner().nextLine();
        System.out.println("Enter Gender");
        this.Sex = getScanner().nextLine();
        System.out.println("Enter Age");
        this.Age = getScanner().nextInt();
        System.out.println("Enter Address");
        this.Address = getScanner().nextLine();
        System.out.println("Enter Email");
        this.Email = getScanner().nextLine();
    }

    @Override
    public String toString() {
        return "Student{" +
                "rollNo='" + rollNo + '\'' +
                ", Name='" + Name + '\'' +
                ", Sex='" + Sex + '\'' +
                ", Email='" + Email + '\'' +
                ", Address='" + Address + '\'' +
                ", Age=" + Age +
                '}';
    }
}


avatar
Chu Quốc Việt [community,C2010L]
2021-08-12 15:05:07


#Student.java


/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package HashMap;

import java.util.Scanner;

/**
 *
 * @author quocviet
 */
public class Student {

    String Rollno, Name, Sex, Age, Email, Address;

    public Student() {
    }

    public Student(String Rollno, String Name, String Sex, String Age, String Email, String Address) {
        this.Rollno = Rollno;
        this.Name = Name;
        this.Sex = Sex;
        this.Age = Age;
        this.Email = Email;
        this.Address = Address;
    }

    public void input() {
        Scanner scan = new Scanner(System.in);
        System.out.println("Nhap msv :");
        Rollno = scan.nextLine();
        System.out.println("Nhap ten :");
        Name = scan.nextLine();
        System.out.println("Nhap gioi tinh :");
        Sex = scan.nextLine();
        System.out.println("Nhap tuoi :");
        Age = scan.nextLine();
        System.out.println("Nhap email :");
        Email = scan.nextLine();
        System.out.println("Nhap dia chi :");
        Address = scan.nextLine();
    }
    public void display(){
        System.out.println(this);
    }
    @Override
    public String toString() {
        return  "Rollno=" + Rollno + ", Name=" + Name + ", Sex=" + Sex + ", Age=" + Age + ", Email=" + Email + ", Address=" + Address ;
    }
    
}


#Test.java


/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package HashMap;

import java.util.Map;
import java.util.Scanner;
import java.util.HashMap;

/**
 *
 * @author quocviet
 */
public class Test {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Map<String, Student> maps = new HashMap<>();
        Scanner scan = new Scanner(System.in);
        int choice;
        do {
            showMenu();
            choice = Integer.parseInt(scan.nextLine());
            switch (choice) {
                case 1:
                    System.out.println("Nhap so sinh vien");
                    int n = Integer.parseInt(scan.nextLine());
                    for (int i = 0; i < n; i++) {
                        System.out.println("sinh vien thu " + (i + 1));
                        Student std = new Student();
                        std.input();
                        maps.put(std.Name, std);
                    }
                    break;
                case 2:
                    for (Map.Entry<String, Student> entry : maps.entrySet()) {
                        Student value = entry.getValue();
                        System.out.println(value);
                    }
                    break;
                case 3:
                    System.out.println(" Nhap ma sinh vien can tim kiem:");
                    String msv = scan.nextLine();
                    for (Map.Entry<String, Student> std : maps.entrySet()) {
                        if (std.getKey().equalsIgnoreCase(msv)) {
                            System.out.println("Sinh vien tim thay co msv:"+msv+"la :" + std);
                        }
                        else{
                            System.out.println("ko tim thay!!");
                        }
                        
                    }
                    break;

            }
        } while (choice != 3);
    }

    static void showMenu() {
        System.out.println("1. Nhap n sinh vien");
        System.out.println("2. Hien thi thong tin sinh vien");
        System.out.println("3. Tim kiem sinh vien");
    }
}


avatar
Triệu Văn Lăng [T2008A]
2021-03-19 08:58:05



/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package bai1058;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

/**
 *
 * @author MTLS
 */
public class main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        Map<String, sinhvien> stdM = new HashMap<>();
        int choose;
        do {
            showMenu();

            choose = Integer.parseInt(scan.nextLine());
            switch (choose) {
                case 1:
                    int n;
                    System.out.println("Nhap N: ");
                    n = Integer.parseInt(scan.nextLine());
                    for (int i = 0; i < n; i++) {
                        sinhvien sv = new sinhvien();
                        sv.input();
                        stdM.put(sv.getRollNo(), sv);
                    }
                    break;
                case 2:
                    System.out.println("Thong tin sinh vien: ");
                    for (Map.Entry<String, sinhvien> entry : stdM.entrySet()) {
                        String key = entry.getKey();
                        sinhvien value = entry.getValue();
                        value.display();

                    }
                    break;
                case 3:
                    System.out.println("Nhap rollNo can tim sinh vien: ");
                    String rollNo = scan.nextLine();

                    sinhvien svFind = stdM.get(rollNo);
                    svFind.display();

                    break;
                case 4:
                    System.out.println("Thoat");
                    break;
                default:
                    System.out.println("Vui long nhap lai");
                    break;
            }

        } while (choose != 3);
    }

    private static void showMenu() {
        System.out.println("1. Nhap N sinh vien ");
        System.out.println("2. Hien thi thong tin sinh vien");
        System.out.println("3. Tim kiem sinh vien theo rollNo");
        System.out.println("4. Thoat");
        System.out.println("Moi chon");
    }
}


avatar
Triệu Văn Lăng [T2008A]
2021-03-19 08:57:45



/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package bai1058;

import java.util.Scanner;

/**
 *
 * @author MTLS
 */
public class sinhvien {
    String rollNo, Name, sex, Email, Address;
    int age;

    public sinhvien() {
    }

    public sinhvien(String rollNo, String Name, String sex, String Email, String Address, int age) {
        this.rollNo = rollNo;
        this.Name = Name;
        this.sex = sex;
        this.Email = Email;
        this.Address = Address;
        this.age = age;
    }

    public String getRollNo() {
        return rollNo;
    }

    public String getName() {
        return Name;
    }

    public String getSex() {
        return sex;
    }

    public String getEmail() {
        return Email;
    }

    public String getAddress() {
        return Address;
    }

    public int getAge() {
        return age;
    }

    public void setRollNo(String rollNo) {
        this.rollNo = rollNo;
    }

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

    public void setSex(String sex) {
        this.sex = sex;
    }

    public void setEmail(String Email) {
        this.Email = Email;
    }

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

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

    @Override
    public String toString() {
        return "sinhvien{" + "rollNo=" + rollNo + ", Name=" + Name + ", sex=" + sex + ", Email=" + Email + ", Address=" + Address + ", age=" + age + '}';
    }
    
    
    public void input() {
        Scanner scan = new Scanner(System.in);
        System.out.println("Nhap rollNo: ");
        rollNo = scan.nextLine();
        
        System.out.println("Nhap Name: ");
        Name = scan.nextLine();
        
        System.out.println("Nhap age: ");
        age = Integer.parseInt(scan.nextLine());
        
        System.out.println("Nhap sex: ");
        sex = scan.nextLine();
        
        System.out.println("Nhap Email: ");
        Email = scan.nextLine();
        
        System.out.println("Nhap Address: ");
        Address = scan.nextLine();
    }
    public void display() {
        System.out.println(this);
    }
    
    
}


avatar
hainguyen [T2008A]
2021-03-11 14:14:38



/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package java2.lesson1;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

/**
 *
 * @author Admin
 */
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        
        Map<String, Sinhvien> maps = new HashMap<>();
        
        int choose;
        do{
          showMenu();
          choose = Integer.parseInt(scan.nextLine());
          switch(choose){
              case 1:
                  System.out.println("Nhap so sv: ");
                  int sum = Integer.parseInt(scan.nextLine());
                  for (int i = 0; i < 10; i++) {
                      Sinhvien std = new Sinhvien();
                      std.input();
                      maps.put(std.Rollno, std);
                  }
                  break;
              case 2:
                  maps.entrySet().forEach((Sinhvien) -> {System.out.println(Sinhvien);});
                  break;
              case 3:
                  System.out.println("Ket thuc");
                  break;
              default :
                  System.out.println("Nhap sai");
                  break;
                  
          }
          
        } while (choose != 3 );
        
    }
    
    static void showMenu() {
        System.out.println("1. Nhap N sinh vien");
        System.out.println("2. Hien thi thong tin");
        System.out.println("3. Tim kiem ");
        System.out.println("4. Thoat");
    }
}


avatar
hainguyen [T2008A]
2021-03-11 14:14:24



/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package java2.lesson1;

import java.util.Scanner;

/**
 *
 * @author Admin
 */
public class Sinhvien {
    String Rollno;
    String Name;
    String Sex;
    int Age;
    String Email;
    String Address;

    public Sinhvien() {
    }

    public Sinhvien(String Rollno, String Name, String Sex, int Age, String Email, String Address) {
        this.Rollno = Rollno;
        this.Name = Name;
        this.Sex = Sex;
        this.Age = Age;
        this.Email = Email;
        this.Address = Address;
    }

    @Override
    public String toString() {
        return "Sinhvien{" + "Rollno=" + Rollno + ", Name=" + Name + ", Sex=" + Sex + ", Age=" + Age + ", Email=" + Email + ", Address=" + Address + '}';
    }
    
    public void input() {
        Scanner scan = new Scanner(System.in);
        
        System.out.println("Nhap Rollno: ");
        Rollno = scan.nextLine();
        System.out.println("Nhap Name: ");
        Name = scan.nextLine();
        System.out.println("Nhap Sex: ");
        Sex = scan.nextLine();
        System.out.println("Nhap Age: ");
        Age = scan.nextInt();
        System.out.println("Nhap Email: ");
        Email = scan.nextLine();
        System.out.println("Nhap Address: ");
        Address = scan.nextLine();
    }
}


avatar
Trần Văn Lâm [T2008A]
2021-03-11 06:07:14


#Student.java


/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package lesson2;

/**
 *
 * @author Administrator
 */
public class Student {
    String Rollno;
    String Name;
    String Sex;
    int Age;
    String Email;
    String Address;

    public Student() {
    }

    public Student(String Rollno, String Name, String Sex, int Age, String Email, String Address) {
        this.Rollno = Rollno;
        this.Name = Name;
        this.Sex = Sex;
        this.Age = Age;
        this.Email = Email;
        this.Address = Address;
    }

    public String getRollno() {
        return Rollno;
    }

    public void setRollno(String Rollno) {
        this.Rollno = Rollno;
    }

    public String getName() {
        return Name;
    }

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

    public String getSex() {
        return Sex;
    }

    public void setSex(String Sex) {
        this.Sex = Sex;
    }

    public int getAge() {
        return Age;
    }

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

    public String getEmail() {
        return Email;
    }

    public void setEmail(String Email) {
        this.Email = Email;
    }

    public String getAddress() {
        return Address;
    }

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

    @Override
    public String toString() {
        return "Student{" + "Rollno=" + Rollno + ", Name=" + Name + ", Sex=" + Sex + ", Age=" + Age + ", Email=" + Email + ", Address=" + Address + '}';
    }
    
    public void Input(){
        Scanner scan = new Scanner(System.in);
        System.out.println("Nhap Ma SV:");
        Rollno = scan.nextLine();
        System.out.println("Nhap ten SV:");
        Name = scan.nextLine();
        System.out.println("Nhap Gioi Tinh:");
        Sex = scan.nextLine();
        System.out.println("Nhap tuoi:");
        Age = scan.nextInt();
        System.out.println("Nhap Email:");
        Email = scan.nextLine();
        System.out.println("Nhap Dia Chi:");
        Address = scan.nextLine();
    }
}


#Test.java


/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package lesson2;

import java.util.HashMap;
import java.util.Map;



/**
 *
 * @author Administrator
 */
public class Test {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        Map<String, Student> maps = new HashMap<>();
        int choose;
        do{
            showMenu();
            choose = Integer.parseInt(scan.nextLine());
            switch(choose){
                case 1:
                        System.out.println("Nhap so SV:");
                        int num = Integer.parseInt(scan.nextLine());
                        for (int i = 0; i < num; i++) {
                            Student std = new Student();
                            std.Input();
                            maps.put(std.Rollno, std);
                    }
                    break;
                case 2:
                    maps.entrySet().forEach((student) -> {
                        System.out.println(student);
            });
                    break;
                case 3:
                    break;
                case 4:
                    System.out.println("Ket thuc!!!");
                    break;
                default :
                    System.out.println("Nhap sai!!!");
                    break;
            }
        }while(choose!=4);
          
    }
    static void showMenu(){
        System.out.println("1.Nhap thong tin N Sinh vien");
        System.out.println("2.In thong tin SV");
        System.out.println("3.Tim kiem thong tin Sinh vien theo maSV");
        System.out.println("4.Thoat!!!");
    }
}


avatar
vuong huu phu [T2008A]
2021-03-10 10:32:26



/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package sinh_vien;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

/**
 *
 * @author Admin
 */
public class Test {

    public static void main(String[] args) {
Map< String, Sinh_vien> sv = new HashMap<>();
int lua_chon;
Scanner scan = new Scanner(System.in);
        do {            
            menu();
            System.out.println("NHap lua chon");
            lua_chon =Integer.parseInt(scan.nextLine());
            switch(lua_chon){
                case 1:
                    int n ;
                    System.out.println("Nhap so luong can them ");
                    n = Integer.parseInt(scan.nextLine());
                    for (int i = 0; i < n; i++) {
                        Sinh_vien sv1 = new Sinh_vien();
                        sv1.nhap();
                        sv.put(sv1.RollNo, sv1);
                    }
                    break;
                case 2:
                    System.err.println("");
                    for (Map.Entry<String, Sinh_vien> sinhv : sv.entrySet()) {
                        System.out.println(sinhv);
                    }
                    break;
                case 3:
                    System.out.println("Nhap ma sinh vien ");
                    String rl= scan.nextLine();
                    for (Map.Entry<String, Sinh_vien> entry : sv.entrySet()) {
                        if(entry.getKey().equalsIgnoreCase(rl)){
                            System.out.println(entry);
                        }
                    }
                    break;
                default:
                    System.out.println("Nhap lai");
                    
            }
        } while (true);
    }

    public static void menu() {
        System.out.println(" 1 Nhap n sinh vien");
        System.out.println(" 2 in thong tin sinh vien");
        System.out.println(" 3 Tim kiem thong tin sinh vien");
    }
}