判断一个括号字符串是否匹配

package test;

import java.util.Scanner;
import java.util.Stack;

public class Main7 {
public static void main(String[] args){

Scanner in = new Scanner(System.in);
String s = in.nextLine();
boolean b =isMatch(s);
System.out.println(b );
}

static boolean isMatch(String s) {
Stack<Character> sk = new Stack<Character>();
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == '(') {
sk.push('(');
}
if (s.charAt(i) == ')') {
if (!sk.isEmpty() && sk.pop() == '(')
continue;
else
return false;
}
if (s.charAt(i) == '{') {
sk.push('{');
}
if (s.charAt(i) == '}') {
if (!sk.isEmpty() && sk.pop() == '{')
continue;
else
return false;
}
}
if (sk.isEmpty())
return true;
else
return false;
}
}