public class sclass {
int top=0,x;
int []buffer=new int[4];
public void push(int x){
buffer[top]=x;
top++;
}
public int pop(){
top--;
return buffer[top];
}
}

قسمت main برنامه:

public static void main(String[] args) {
Scanner console=new Scanner(System.in);
int i,j,x;
sclass a=new sclass();
for(i=0;i<=3;i++){
x=console.nextInt();
a.push(x);
}
j=3;
while(j>=0){
System.out.print(a.pop());
j--;
}
}

}