Java implementing stack with custom class

If you want to create a custom class to implement stack in java, you can do something like this:-

import java.util.ArrayList;
import java.util.List;

interface StackList<T> {

    public boolean push(T data);

    public T pop();

    public int size();
}

public class Stack<T> implements StackList<T> {

    private final int max;
    private int top = -1;
    private final List<T> stack;

    public Stack(int size) {
        max = size - 1;
        stack = new ArrayList<>(size);
    }

    public boolean push(T data) {
        if (top <= max) {
            top += 1;
            stack.add(top, data);
            return true;
        }
        throw new IndexOutOfBoundsException("Stack is already full");
    }

    public T pop() {
        T data;
        if (top >= 0) {
            data = stack.get(top);
            top -= 1;
            return data;
        }
        throw new IndexOutOfBoundsException("Stack is already empty");
    }

    public int size() {
        return stack.size();
    }
}










 
You can use the above class as follows:-

import java.util.Scanner;

public class StackTest {

    Stack<Integer> stack = new Stack<>(5);
    int data;
    Scanner scan = new Scanner(System.in);

    void input() {
        try {
            do {
                System.out.printf("Enter data to enter or -11 to exit: ");
                data = scan.nextInt();
                if (data == -11) {
                    break;
                }
                stack.push(data);
            } while (true);
        } catch (IndexOutOfBoundsException e) {
            System.err.println("Error Occurred!\n" + e.getMessage());
            System.exit(0);
        }
    }

    void size() {
        System.out.println("\nStack size: " + stack.size());
    }

    void remove() {
        try {
            int data;
            do {
                data = stack.pop();
                System.out.printf("Removed data: " + data + "\nEnter -11 to exit: ");
                data = scan.nextInt();
            } while (data != -11);
        } catch (IndexOutOfBoundsException e) {
            System.err.println("Error Occurred!\n" + e.getMessage());
            System.exit(0);
        }
    }

    public static void main(String[] args) {
        StackTest st = new StackTest();
        st.input();
        st.size();
        st.remove();
    }
}