Balanced String

A program to determine if the parentheses (), the brackets [], and the braces {}, in a string are balanced.

For example:

{{)(}} is not balanced because ) comes before (

({)} is not balanced because) is not balanced between {} and similarly the { is not balanced between ()

[({})] is balanced

{}([]) is balanced

{()}[[{}]] is balanced

import java.util.Stack;

public class BalancedParenthesis {

     public static void main(String[] args) {

          BalancedParenthesis bp = new BalancedParenthesis();

          System.out.println(bp.isBalanced("{{)(}}"));

          System.out.println(bp.isBalanced("({)}"));

          System.out.println(bp.isBalanced("[({})]"));

          System.out.println(bp.isBalanced("{}([])"));

          System.out.println(bp.isBalanced("{()}[[{}]]"));

     }

     public boolean isBalanced(String string) {

          Stack stack = new Stack<>();

          for (String token : string.split("")) {

               if ("(".equals(token) || "[".equals(token) || "{".equals(token)) {

                    stack.push(token);

               } else if (")".equals(token) || "]".equals(token) || "}".equals(token)) {

                    if (stack.isEmpty()) {

                         return false;

                    }

                    String pop = stack.pop();

                    if ((")".equals(token) && !"(".equals(pop))

                              || ("]".equals(token) && !"[".equals(pop))

                              || ("}".equals(token) && !"{".equals(pop))) {

                         return false;

                    }

               }

          }

          return true;

     }

}

Output:

false

false

true

true

true