java使用正则表达式在文档里找匹配

public static void main(String[] args) {

        String str = "123我是456张三789的学生";
        String regex2 = "\\d{1,}";
        Pattern p = Pattern.compile(regex2);
        Matcher matcher = p.matcher(str);
        while(matcher.find()){
            System.out.println(matcher.group());
        }

 }