multiMap string to Map

MultiMapPattern.java

private static final String MULTIMAP_PATTERN_REGEX = "(, |\\s*)(.*?)=\\[(.*?)]";
private static final Pattern MULTIMAP_PATTERN = Pattern.compile(MULTIMAP_PATTERN_REGEX);


public static Map<String, String> convertHeaderMultimapStringToHashMap(String text) {
    Map<String, String> map = new HashMap<>();
    text = text.substring(1, text.length() - 1);
    Matcher matcher = MULTIMAP_PATTERN.matcher(text);
    while (matcher.find()) {
        map.put(matcher.group(2).toUpperCase(), matcher.group(3)); //header name ignore upper or lower case
    }
    return map;
}

example string : {Transfer-Encoding=[chunked], Content-Type=[application/json;charset=UTF-8]}