Stack

import java.util.Stack;

public class StackTest {
	public static void main(String[] args) {
		Stack<String> stack = new Stack<String>();
		System.out.println("now the stack is " + isEmpty(stack));
		stack.push("1");
		stack.push("2");
		stack.push("3");
		stack.push("4");
		stack.push("5");
		System.out.println("now the stack is " + isEmpty(stack));
		System.out.println(stack.peek());
		System.out.println(stack.pop());
		System.out.println(stack.pop());
		System.out.println(stack.search("2"));
	}
	
	public static String isEmpty(Stack<String> stack) {
		return stack.empty() ? "empty" : "not empty";
	}
}

　　

now the stack is empty
now the stack is not empty
5
5
4
2

search(Object o)

Returns the 1-based position where an object is on this stack.