code: public Ftp setMode(FtpMode mode) {
  		this.mode = mode;
  		switch (mode) {
  		case Active:
  			this.client.enterLocalActiveMode();
  			break;
  		case Passive:
  			this.client.enterLocalPassiveMode();
  			break;
  		}
  		return this;
  	}
docs: 设置FTP连接模式，可选主动和被动模式
  
  @param mode 模式枚举
  @return this
  @since 4.1.19