code: private static String readInitParam(Configuration configuration, String key) {
          String value = null;
          try {
              String param = (String) configuration.getProperty(key);
              if (param != null) {
                  param = param.trim();
                  if (param.length() > 0) {
                      value = param;
                  }
              }
          } catch (Exception e) {
              String msg = "initParameter config [" + key + "] error";
              logger.warn(msg, e);
          }
          return value;
      }
docs: 读取配置参数.
  
  @param key 配置参数名
  @return 配置参数值，如果不存在当前配置参数，或者为配置参数长度为0，将返回null