Lesson 17. Changed

Computer.java

package com.example.lesson17;

public class Computer {
    private String processor;
    private String ram;
    private String hdd;
    private String videoCard;
    private String powerSupply;

    public Computer() {
    }

    public Computer(String processor, String ram, String hdd, String videoCard, String powerSupply) {
        this.processor = processor;
        this.ram = ram;
        this.hdd = hdd;
        this.videoCard = videoCard;
        this.powerSupply = powerSupply;
    }

    public String getProcessor() {
        return processor;
    }

    public String getRam() {
        return ram;
    }

    public String getHdd() {
        return hdd;
    }

    public String getVideoCard() {
        return videoCard;
    }

    public String getPowerSupply() {
        return powerSupply;
    }

    @Override
    public String toString() {
        String result = "Processor: ";
        result += getProcessor() + "\n";
        result += "RAM: " + getRam() + "\n";
        result += "HDD: " + getHdd() + "\n";
        result += "Video Card: " + getVideoCard() + "\n";
        result += "Power Supply: " + getPowerSupply() + "\n";
        return result;
    }
}

ComputerStore.java

package com.example.lesson17;

import java.util.ArrayList;
import java.util.ListIterator;

public class ComputerStore {    /* for */
    public void printByIndex(ArrayList<Computer> catalogComputersList) {
        for (int i = 0; i < catalogComputersList.size(); i++) {
            System.out.println(catalogComputersList.get(i));
        }
    }    /* ListIterator */

    public void printIterator(ArrayList<Computer> catalogComputersList) {
        ListIterator<Computer> computerIterator = catalogComputersList.listIterator();
        while (computerIterator.hasNext()) {
            System.out.println(computerIterator.next());
        }
    }    /* for-each */

    public void printForEach(ArrayList<Computer> catalogComputersList) {
        for (Computer hardware : catalogComputersList) {
            System.out.println(hardware);
        }
    }
}

Main.java

package com.example.lesson17;

import java.util.ArrayList;

public class Main {
    public static void main(String[] args) {
        Computer myComp = new Computer("50 x 3.2 GHZ", "640 GB", "10 PetaBytes", "4 x Radeon Z0", "GigaWatt");
        ComputerStore cs = new ComputerStore();
        ArrayList<Computer> catalogComputersList = new ArrayList<Computer>();
        catalogComputersList.add(new Computer("2 x 1.6 GHz", "4 GB", "512 GB", "GeForce 210", "350 Watt"));
        catalogComputersList.add(new Computer("2 x 3.2 GHZ", "8 GB", "1 TB", "Radeon R7 370", "550 Watt"));
        catalogComputersList.add(new Computer("2 x 3.7 GHz", "16 GB", "1 TB", "GeForce GTX 970", "550 Watt"));
        System.out.println("-------- for -------");
        cs.printByIndex(catalogComputersList);
        System.out.println("--- ListIterator ---");
        cs.printIterator(catalogComputersList);
        System.out.println("----- for-each -----");
        cs.printForEach(catalogComputersList);
        System.out.println("----- Hardware -----");
        System.out.println(myComp.getProcessor()); // null
        System.out.println(myComp.toString()); // null
    }
}