Basic Stack Implementation (Java)

BasicStack.java

public class BasicStack {

    private Object[] array = null;
    private boolean debug = false;

    public BasicStack() {
	this(10);
    }

    public BasicStack(int capacity) {
	array = new Object[capacity];
    }

    /** @param debug If true, print for each pop/push operation */
    public BasicStack(int capacity, boolean debug) {
	this(capacity);
	this.debug = debug;
    }

    public void push(Object t) {
	for (int i = 0; i < array.length; i++) {
	    if (isEmptyAt(i)) {
		array[i] = t;
		return;
	    }
	}
	resize(t);
	if (debug) {
	    this.print();
	}
    }

    private void resize(Object objectToBeInserted) {
	int pos = array.length;
	Object[] newArray = new Object[array.length * 2];
	for (int i = 0; i < array.length; i++) {
	    newArray[i] = array[i];
	}
	newArray[pos] = objectToBeInserted;
	array = newArray;
    }

    public Object pop() {
	Object result = null;
	for (int i = array.length - 1; i >= 0; i--) {
	    if (isEmptyAt(i)) continue;
	    else {
		result = array[i];
		array[i] = null;
		break;
	    }
	}
	if (debug) {
	    this.print();
	}
	return result;
    }

    private boolean isEmptyAt(int index) {
	return array[index] == null;
    }

    @Override
    public String toString() {
	String s = "| ";
	for (int i = 0; i < array.length; i++) {
	    s += (array[i] + " | ");
	    if (i == array.length - 1) {
		s += "\n";
	    }
	}
	return s;
    }

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

    public static void main(String[] args) {
	BasicStack stack = new BasicStack(3);
	stack.push(1);	stack.print();
	stack.push(2); 	stack.print();
	stack.push(3);	stack.print();
	stack.push(4);	stack.print();
	stack.push(5);	stack.print();
	stack.pop();	stack.print();

	System.out.println("ROUND 2");
	stack = new BasicStack(2, true);
	stack.push(1);	
	stack.push(2); 	
	stack.push(3);	
	stack.push(4);	
	stack.push(5);	
	stack.pop();  
	
    }

}