Я видел некоторые проблемы в вашем коде, это моя исправленная версия
import java.util.Scanner;
import java.util.Stack;
// use Capital letters in the beginning of class names
public class BracketCheck {
public static void main(String[] args) {
Stack<Character> stack = new Stack<>();
Scanner input = new Scanner(System.in);
String buff;
System.out.println("please enter brackets & text");
buff = input.nextLine();
input.close();
// using java8 makes iterating over the characters of a string easier
buff.chars().forEach(current -> {
// if <current> is an opening bracket, push it to stack
if (current == '(' || current == '{' || current == '[') {
stack.push((char) current);
}
// if <current> is a closing bracket, make sure it is matching an opening
// bracket or alert and return
else if (current == ')' || current == '}' || current == ']') {
if (!match(stack, (char) current)) {
System.out.println("no good");
return;
}
}
});
// if, after we finished iterating the string, stack is empty, all opening
// brackets had matching closing brackets
if (stack.isEmpty()) {
System.out.println("bout time......");
}
// otherwise, alert
else {
System.out.println("woah");
}
}
private static boolean match(Stack<Character> stack, Character closer) {
// if stack is empty, the closer has no matching opener
if (stack.isEmpty()) {
return false;
} else {
// get the most recent opener and verify it matches the closer
Character opener = stack.pop();
if (opener == '(' && closer == ')')
return true;
else if (opener == '[' && closer == ']')
return true;
else if (opener == '{' && closer == '}')
return true;
else
return false;
}
}
}