Question

我收到了这条消息：

 "data: "{"cmd":"gw","seqno":515816,"EUI":"000DB53113683569","ts":1510584501221,"fcnt":1,"port":2,"freq":868100000,"toa":1482,"dr":"SF12 BW125 4/5","ack":false,"gws":[{"rssi":-71,"snr":9.5,"ts":1510584501221,"time":"2017-11-13T14:48:21.218869Z","gweui":"B827EBFFFF6A14DD","lat":50.0751806,"lon":14.4022641}],"bat":255,"data":"0002560000000000000000"}""

我需要收集＆＃34;数据：＆＃34;并且最后＆＃34;

如果我使用JSON节点，我只需要JSON消息它只是因为＆＃34;数据而写了一个错误：＆＃34;

Answer 1

您可以使用功能节点来剪切字符串。像这样：

msg.payload = msg.payload.substring(7,msg.payload.length - 1);
return msg;

然后将其连接到JSON节点。

Answer 2

作为替代方案，您可以添加缺少的{}，然后添加JSON.parse。

var string = "{" + msg.payload +"}"
var dataObject = JSON.parse(string)

msg.payload = dataObject.data
return msg

如何在节点红色

2 个答案: