getValue static method

String getValue({ String keyName = "", String json = "", bool isFillWhitespace = false, })

Implementation

static String getValue({String keyName = "", String json = "", bool isFillWhitespace = false}) {
  if (keyName.isEmptyString || json.isEmptyString) {
    return "";
  }
  if (isFillWhitespace == true) {
    json = json.replaceAll("\\r|\\n|\\s|\\t", "");
  }
  String regex = "((\"" +
      keyName +
      "\")|('" +
      keyName +
      "')):(((\\[(.+)\\](\\,|\\}))|(\\{(.+)\\}(\\,|\\})))|((.*?)((\\,|\\})(\\s\\S)*)))";
  var matcher = RegExp(regex, multiLine: true);
  var matches = matcher.allMatches(json);
  String value = "";
  matches.forEach((element) {
    //避免null出错
    value = element.groupCount > 0 ? (element.group(0) ?? "").trim() : "";
    //根据:分隔
    int index = value.indexOf(":");
    if (index >= 0 && (index + 1) < value.length) {
      value = value.substring(index + 1).trim();
      int start = 0;
      if (value.startsWith("\"") || value.startsWith("'")) {
        start = 1;
      }
      //去掉前面引号
      //去掉最后一个字符包含的,或}
      value = value.substring(start, value.length - 1);
      value = value.trim();
      //去掉后面引号
      int end = value.length;
      if (value.endsWith("\"") || value.endsWith("'")) {
        end -= 1;
      }
      value = value.substring(0, end);
      return;
    }
  });
  return value;
}