主线程java.util.NoSuchElementException异常异常

import java.util.*;

public class NoSuchElementExceptionExample {
    public static void main(String[] args) {
        List<String> list = Arrays.asList("a", "b", "c");
        Iterator<String> iterator = list.iterator();

        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }

        int index = 3;
        if (index >= 0 && index < list.size()) {
            System.out.println(list.get(index));
        } else {
            System.out.println("Index out of bounds");
        }

        Map<String, String> map = new HashMap<>();
        map.put("key1", "value1");
        if (map.containsKey("key2")) {
            System.out.println(map.get("key2"));
        } else {
            System.out.println("Key not found");
        }
    }
}