Stack Data Structure Using Array in Java

//Stack DataStructure Using Array
package stack;
public class MyStack {
    private int maxSize;
    private long[] stackArray;
    private int top;

    public MyStack(int s) {
        maxSize = s;
        stackArray = new long[maxSize];
        top = -1;
    }
    public void push(long j) {
        if(isFull()) {
            System.out.println("Stack is Full");
        } else {
            top++;
            stackArray[top] = j;
        }
    }
    public long pop() {
        if(top < 0) {
            System.out.println("Stack Underflow");
            return 0;
        }else{
            long item = stackArray[top];
            top--;
            return item;
        }
    }
    public long peek() {
        return stackArray[top];
    }
    public boolean isEmpty() {
        return (top == -1);
    }
    public boolean isFull() {
        return (top == maxSize-1);
    }

    public static void main(String[] args) {
        MyStack theStack = new MyStack(10); 
        theStack.push(10);
        theStack.push(20);
        theStack.push(30);
        theStack.push(40);
        theStack.push(50);

        while (!theStack.isEmpty()) {
            long value = theStack.pop();
            System.out.println("Values are: "+value);            
        }
        System.out.println("Is Empty Now: "+theStack.isEmpty());  //true
    }
}

//Output
Values are: 50
Values are: 40
Values are: 30
Values are: 20
Values are: 10
Is Empty Now: true