Stack in java (Push and Pop)

import java.util.Arrays;


public class Stack {


public static  int stacksize = 10;
public static int topstack=-1;
public static String[] arr=new String[stacksize];


public  String push(String val)
{


if(topstack+1<stacksize)
{
topstack++;
arr[topstack]=val;
return arr[topstack];

}
else

System.out.println("Stack is full");
   return "-1";
}
public String pop()
{
if(topstack>=0)
{
topstack--;


return arr[topstack];
}
else
System.out.println("Stackis full");
   return "-1";

}
public static void main(String[] args)
{

Stack stk=new  Stack();
// stk.push("54");
//stk.push("4");
System.out.println(stk.push("5"));
System.out.println(stk.push("7"));
System.out.println(stk.push("4"));
System.out.println(stk.push("2"));
System.out.println(stk.push("1"));
System.out.println(stk.push("2"));
System.out.println(stk.push("6"));
System.out.println(stk.push("1"));
System.out.println(stk.push("3"));
// System.out.println(stk.push("7"));
System.out.println(stk.push("......................."));

//System.out.println(Arrays.toString(arr));

for(int i=0;i<arr.length-1;i++)
{
System.out.println(stk.pop());

// System.out.println(Arrays.toString(arr));
}
}

}