public boolean getBoolean(final String key) {
    if (containsKey(key)) {
      return "true".equalsIgnoreCase(get(key));
    } else {
      throw new UndefinedPropertyException("Missing required property '" + key
          + "'");
    }
  }
Returns true if the value equals "true". If the value is null, then an
UndefinedPropertyException is thrown.
dss-appconn/appconns/dss-eventchecker-appconn/src/main/java/com/webank/wedatasphere/dss/appconn/eventchecker/utils/Props.java