在eclipse-ditto mappingcontext中，我放置了以下incomingScript：
function mapToDittoProtocolMsg(headers, textPayload, bytePayload, contentType) {
switch (contentType) {
case "application/json":
var jsonData = JSON.parse(textPayload);
var temperature = jsonData.temp;
var humidity = jsonData.hum;
var path;
var value;
if (temperature != null && humidity != null) {
path = "/features";
value = {
temperature: {
properties: {
value: temperature
}
},
humidity: {
properties: {
value: humidity
}
}
};
} else if (temperature != null) {
path = "/features/temperature/properties/value";
value = temperature;
} else if (humidity != null) {
path = "/features/humidity/properties/value";
value = humidity;
}
if (!path || !value) {
return null;
}
return Ditto.buildDittoProtocolMsg("tenant_aloxy", headers["device_id"], "things", "twin", "commands", "modify", path, headers, value);
break;
case "application/octet-stream":
let byteBuf = Ditto.asByteBuffer(bytePayload);
var path = "/features/alp/properties/value";
var value = 21;
return Ditto.buildDittoProtocolMsg("tenant_aloxy", headers["device_id"], "things", "twin", "commands", "modify", path, headers, value);
default:
return null;
}
}
当我发送二进制数据时，我按预期达到了第二种情况。但是，当它尝试将传入的数据转换为字节缓冲区（Ditto.asByteBuffer（bytePayload）;）时，将引发以下异常：
ReferenceError：未定义“ dcodeIO”。
最佳答案
如文档中所述，“ Ditto”范围中的该辅助函数需要“ ByteBuffer.js”库：https://www.eclipse.org/ditto/connectivity-mapping.html#bytebufferjs（dcodeIO用作该库的范围）。
这意味着您只需启用该库即可在映射的配置中加载：https://www.eclipse.org/ditto/connectivity-mapping.html#configuration-options
{
"incomingScript": "...",
"outgoingScript": "...",
"loadBytebufferJS": true,
"loadLongJS": true
}
之后，您应该可以使用
Ditto.asByteBuffer()关于javascript - Ditto.asByteBuffer(bytePayload)引发异常，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/54236444/