Java basic- Overview - viết chương trình điều khiển TIVI bằng java

#CTivi.java

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package bt999;

/**
 *
 * @author diepvan
 */
public class CTivi {
    String[] channelList;
    boolean isOn;
    String currentChannel;
    int currentIndex = 0;

    public CTivi() {
        isOn = false;
        channelList = new String[]{"VTV1", "VTV2", "VTV3"};
        currentChannel = "VTV1";
    }

    public CTivi(String[] channelList) {
        this.channelList = channelList;
        isOn = false;
        if(this.channelList.length > 0) {
            currentChannel = channelList[0];
        }
    }
    
    String searchNextChannel(boolean isForward) {
        if(channelList.length == 0) return null;
        
        if(isForward) {
            currentIndex++;
            if(currentIndex >= channelList.length) {
                currentIndex = 0;
            }
        } else {
            currentIndex--;
            if(currentIndex < 0) {
                currentIndex = channelList.length - 1;
            }
        }
        
        currentChannel = channelList[currentIndex];
        return currentChannel;
    }
    
    void On() {
        isOn = true;
        System.out.println("-- Tivi ON --");
    }
    
    void Off() {
        isOn = false;
        System.out.println("-- Tivi Off --");
    }
    
    public void Switch() {
        if(isOn) {
            Off();
        } else {
            On();
        }
    }
    
    /**
     * overloading & override
     * @param channel 
     */
    public void Switch(String channel) {
        Switch();
        if(isOn) {
            System.out.println("Bat dau tim kenh ...");
            boolean isFind = false;
            for (int i = 0; i < channelList.length; i++) {
                if(channelList[i].equalsIgnoreCase(channel)) {
                    currentChannel = channelList[i];
                    currentIndex = i;
                    isFind = true;
                    break;
                }
            }
            
            if(!isFind) {
                System.out.println("Khong tim thay kenh phu hop");
            }
        }
    }
    
    public void nextChannel() {
        if(isOn) {
            searchNextChannel(true);
            System.out.println("Kenh hien tai: " + currentChannel);
        }
    }
    
    public void previousChannel() {
        if(isOn) {
            searchNextChannel(false);
            System.out.println("Kenh hien tai: " + currentChannel);
        }
    }
    
    public void Show() {
        if(isOn) {
            System.out.println("-- Tivi is ON channel: " + currentChannel);
        } else {
            System.out.println("-- Tivi is OFF! --");
        }
    }
}

#Main.java

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package bt999;

import java.util.Scanner;

/**
 *
 * @author diepvan
 */
public class Main {
    public static void main(String[] args) {
        CTivi tivi;
        
        Scanner scan = new Scanner(System.in);
        
        System.out.println("1. Khoi tao mac dinh");
        System.out.println("2. Khoi tao tu thiet lap");
        System.out.println("Chon: ");
        int choose = Integer.parseInt(scan.nextLine());
        
        if(choose == 1) {
            tivi = new CTivi();
        } else {
            System.out.println("Nhap so kenh can them: ");
            int N = Integer.parseInt(scan.nextLine());
            String[] channelList = new String[N];
            for (int i = 0; i < N; i++) {
                System.out.println("Nhap kenh: ");
                channelList[i] = scan.nextLine();
            }
            
            tivi = new CTivi(channelList);
        }
        
        do {
            showMenu();
            choose = Integer.parseInt(scan.nextLine());
            
            switch (choose) {
                case 1:
                    tivi.Switch();
                    break;
                case 2:
                    System.out.println("Nhap kenh can chuyen: ");
                    String channel = scan.nextLine();
                    tivi.Switch(channel);
                    break;
                case 3:
                    tivi.On();
                    break;
                case 4:
                    tivi.Off();
                    break;
                case 5:
                    tivi.nextChannel();
                    break;
                case 6:
                    tivi.previousChannel();
                    break;
                case 7:
                    tivi.Show();
                    break;
                case 8:
                    System.out.println("Thoat!!!");
                    break;
                default:
                    System.out.println("Nhap sai!!!");
            }
        } while(choose != 8);
    }
    
    static void showMenu() {
        System.out.println("1. Chuyen trang thai");
        System.out.println("2. Chuyen trang thai kem theo kenh");
        System.out.println("3. Bat tivi");
        System.out.println("4. Tat tivi");
        System.out.println("5. Chuyen kenh tiep theo");
        System.out.println("6. Chuyen kenh trc do");
        System.out.println("7. Xem tivi");
        System.out.println("8. Thoat");
        System.out.println("Chon: ");
    }
}