关于java正则表达式问题

Question

有个字符串是这样的：data[1223][HOST_NAME]，我需要匹配格式是否是data[xxx][xxx]，然后提取出xxx的值，请问正则要怎么写？

//我自己写的这样的，返回的是false
String s = "data[1223][HOST_NAME]";
Pattern pattern = Pattern.compile("^data\\[\\W\\]*");
Matcher matcher =pattern.matcher(s);
boolean b= matcher.matches();
System.out.println(b);

Answer 1

 String s = "data[1223][HOST_NAME]";
        Pattern pattern = Pattern.compile("\\[([^\\]]+)\\]");
        Matcher matcher =pattern.matcher(s);
        while (matcher.find()) {
            System.out.println(matcher.group(1));
        }