怎么实现 web 端微信自动回复图片功能？

[ajie123]

String imgDir = Constant.config.get("app.img_path");

			String msgId = msg.getString("MsgId");

			FileKit.createDir(imgDir, false);

			String imgUrl = wechatMeta.getBase_uri()
					+ "/webwxgetmsgimg?MsgID=" + msgId + "&skey="
					+ wechatMeta.getSkey() + "&type=slave";

			HttpRequest.get(imgUrl)
					.header("Cookie", wechatMeta.getCookie())
					.receive(new File(imgDir + "/" + msgId + ".png"));
			webwxsendmsg(wechatMeta,"二蛋还不支持图片呢", msg.getString("FromUserName"));
            在这部分代码中怎么实现微信的自动回复功能？