Balanced Parentheses with a Stack

import java.util.*;

public class BalancedParentheses {
    public static void main(String[] args) {
        System.out.println(isBalanced("{[()]}"));            // true
        System.out.println(isBalanced("a(b[c]d)e"));         // true
        System.out.println(isBalanced("([)]"));              // false
        System.out.println(isBalanced("(("));                // false
        System.out.println(isBalanced("())"));               // false
        System.out.println(isBalanced(""));                  // true
    }

    // O(n) time, O(n) space. ArrayDeque is the recommended stack: faster than the legacy Stack class.
    static boolean isBalanced(String text) {
        Map<Character, Character> openerFor = Map.of(')', '(', ']', '[', '}', '{');
        Deque<Character> stack = new ArrayDeque<>();

        for (char c : text.toCharArray()) {
            if (openerFor.containsValue(c)) {
                stack.push(c);                               // an opener: remember it
            } else if (openerFor.containsKey(c)) {
                char expected = openerFor.get(c);
                if (stack.isEmpty() || stack.pop() != expected) return false;   // a closer with no matching opener
            }
        }
        return stack.isEmpty();                              // anything left over was never closed
    }
}