Java End Term: 3 April 2022, Set FN1 (January 2022 term)

1class Vehicle{
2    public void mileage(){
3        System.out.println("Mileage is not known.");
4    }
5    public void tyres(){
6        System.out.println("Number of tyres is not known.");
7    }
8}
9class Airplane extends Vehicle{
10    public void mileage(){
11        System.out.println("Mileage < 1km/L.");
12    }
13}
14class Car extends Vehicle{
15    public void mileage(){
16        System.out.println("Mileage >= 10km/L.");
17    }
18    public void tyres(){
19        System.out.println("Number of tyres is 4.");
20    }
21}
22public class FClass{
23    static void compute(Vehicle s){
24        s.mileage();
25        s.tyres();
26    }
27    public static void main(String[] args){
28        Vehicle c = new Car();
29        Vehicle a = new Airplane();
30        compute(c);
31        compute(a);
32    }
33}

1import java.io.*;
2import java.util.*;
3
4public class FClass{
5    static boolean writeToFile(String filename) {
6        try {
7            FileOutputStream fos = new FileOutputStream(filename);
8            PrintStream bos = new PrintStream(fos);
9            bos.println("it stores two int");
10            bos.println("10 is one");
11            bos.println("20 is another");
12            return true;
13        }catch(IOException e) {
14            return false;
15        }
16    }
17    static boolean readFromFile(String filename) {
18        try {
19            FileInputStream fis = new FileInputStream(filename);
20            Scanner sc = new Scanner(fis);
21            System.out.println(sc.next());
22            System.out.println(sc.nextLine());
23            System.out.println(sc.nextInt());
24            System.out.println(sc.nextLine());
25            return true;
26        }catch(IOException e) {
27            return false;
28        }
29    }
30    public static void main(String[] args) throws IOException{
31        if(writeToFile("E:\\test.txt") == false)
32            System.out.println("write failed");
33        if(readFromFile("E:\\test.txt") == false)
34            System.out.println("read failed");
35    }
36}

1import javax.swing.*;
2import java.awt.*;
3import java.awt.event.*;
4public class FClass extends JFrame implements ActionListener{
5    JButton btnToggle;
6    JPanel pnlColor, pnlBtn;
7    public FClass(){
8        setSize(200, 200);
9        btnToggle = new JButton("Toggle");
10        btnToggle.addActionListener(this);
11        btnToggle.setActionCommand("red");
12        pnlColor = new JPanel();
13        pnlBtn = new JPanel();
14        pnlBtn.add(btnToggle);
15        add(pnlBtn, "South");
16        add(pnlColor, "Center");
17        setVisible(true);
18    }
19
20    public void actionPerformed(ActionEvent e) {
21        /*--------------------*/
22        /*****CODE SEGMENT*****/
23        /*--------------------*/
24    }
25    public static void main(String[] args){
26        new FClass();
27    }
28}