为什么Java中的正则表达式无法将\ s识别为空格字符？

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegexExample {
    public static void main(String[] args) {
        String text = "Hello World";
        String pattern = "\\s";

        Pattern regex = Pattern.compile(pattern);
        Matcher matcher = regex.matcher(text);

        if (matcher.find()) {
            System.out.println("空格字符被匹配到了");
        } else {
            System.out.println("没有匹配到空格字符");
        }
    }
}