Question

在eclipse-ditto映射上下文中，我将以下输入脚本放入：

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，我正在按预期达到开关的第二种情况。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”。

Answer 1

“同上”作用域中的该辅助函数需要使用“ ByteBuffer.js”库，如文档中所述：https://www.eclipse.org/ditto/connectivity-mapping.html#bytebufferjs（dcodeIO被用作该库的作用域）。

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()

Ditto.asByteBuffer（bytePayload）引发异常

1 个答案: