如何使用钉钉群机器人给钉钉群发送消息

钉钉群添加自定义机器人

群内添加自定义机器人，从自定义配置中获取到secret以及accessToken

代码调用

		Long timestamp = System.currentTimeMillis();
        String secret = "secret";
        String accessToken = "accessToken";
        String stringToSign = timestamp + "\n" + secret;
        Mac mac = Mac.getInstance("HmacSHA256");
        mac.init(new SecretKeySpec(secret.getBytes("UTF-8"), "HmacSHA256"));
        byte[] signData = mac.doFinal(stringToSign.getBytes("UTF-8"));
        String sign = URLEncoder.encode(new String(Base64.encodeBase64(signData)),"UTF-8");
        StringBuffer stringBuffer=new StringBuffer();
        stringBuffer.append("https://oapi.dingtalk.com/robot/send?access_token=").append(accessToken);
        //stringBuffer.append("&timestamp=").append(timestamp);
        // stringBuffer.append("&sign=").append(sign);
        System.out.println(stringBuffer.toString());
        //sign字段和timestamp字段必须拼接到请求URL上，否则会出现 310000 的错误信息
        DingTalkClient client = new DefaultDingTalkClient(stringBuffer.toString());
        //参数	类型	必选	说明
        //msgtype	string	true	此消息类型为固定actionCard
        //title	string	true	首屏会话透出的展示内容
        //text	string	true	markdown格式的消息
        //btns	array	true	按钮的信息：title-按钮方案，actionURL-点击按钮触发的URL
        //btnOrientation	string	false	0-按钮竖直排列，1-按钮横向排列
        //hideAvatar	string	false	0-正常发消息者头像，1-隐藏发消息者头像
		//支持多种request方式
        OapiRobotSendRequest.Actioncard actionCard = new OapiRobotSendRequest.Actioncard();
        actionCard.setTitle("杭州天气");
        actionCard.setText("#### 杭州天气 @156xxxx8827\n" +
                "> 9度，西北风1级，空气良89，相对温度73%\n\n" +
                "> ![screenshot](https://gw.alicdn.com/tfs/TB1ut3xxbsrBKNjSZFpXXcXhFXa-846-786.png)\n"  +
                "> ###### 10点20分发布 [天气](http://www.thinkpage.cn/) \n");
        // 此处默认为0
        actionCard.setBtnOrientation("0");
        // 此处默认为0
        actionCard.setHideAvatar("0");
        OapiRobotSendRequest request = new OapiRobotSendRequest();
        request.setMsgtype("actionCard");
        request.setActionCard(actionCard);
        OapiRobotSendResponse rsp = client.execute(request);
        System.out.println(rsp.getBody());