Download File¶

Download a file from an asset.

Operation Permissions¶

Required Authorization	Required Operation Permission
Asset	Read

Request Format¶

GET https://{integration-address}/connect-service/v2.1/files?action=download

Note

{integration-address}：The gateway address of message integration service. Log in to the EnOS Management Console and find it in Help > Environment Information .

Request Parameters (URI)¶

Note

Use one of the following methods to specify the asset:

Include assetId in the request
Include productKey + deviceKey in the request

Name	Location (Path/Query)	Mandatory/Optional	Data Type	Description
orgId	Query	Mandatory	String	The organization ID which the asset belongs to. How to get orgId>>
fileUri	Query	Mandatory	String	The URI of the file. Format: `enos-connect://xxxx`
category	Query	Mandatory	String	The type of the file to be downloaded. The value `feature` stands for model definition and `ota` for OTA-related resources.
assetId	Query	Optional (See Note above)	String	The asset ID. How to get assetID>>
productKey	Query	Optional (See Note above)	String	The product key. To be used with `deviceKey`.
deviceKey	Query	Optional (See Note above)	String	The device key. To be used with `productKey`.

Request Parameters (Header)¶

Name	Mandatory/Optional	Data Type	Description
apim-accesstoken	Mandatory	String	The access token obtained via token authentication. For more information, see Get Access Token

Response Parameters¶

Name	Data Type	Description
The binary data stream of the file	output stream	The response will return an output stream of the returned file with the content dependent on the file.

Samples¶

Request Sample¶

url: https://{apigw-address}/connect-service/v2.1/files?action=download&orgId=yourOrgId&fileUri=yourFileUri&assetId=yourAssetId&category=feature
method: GET
requestHeader:
{
  "apim-accesstoken":"yourAccessToken"
}

Java SDK Sample¶

import com.envisioniot.enos.iot_http_integration.FileCategory;
import com.envisioniot.enos.iot_http_integration.HttpConnection;
import com.envisioniot.enos.iot_http_integration.message.IFileCallback;
import com.envisioniot.enos.iot_mqtt_sdk.core.exception.EnvisionException;
import com.envisioniot.enos.sdk.data.DeviceInfo;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class DownloadFileSample {
    // EnOS Token Server URL and HTTP Broker URL, which can be obtained from Environment Information page in EnOS Console
    static final String TOKEN_SERVER_URL = "http://token_server_url";
    static final String BROKER_URL = "http://broker_url";

    // EnOS Application AccessKey and SecretKey, which can be obtain in Application Registration page in EnOS Console
    static final String APP_KEY = "appKey";
    static final String APP_SECRET = "appSecret";

    // Device credentials, which can be obtained from Device Details page in EnOS Console
    static final String ORG_ID = "orgId";
    static final String ASSET_ID = "assetId";
    static final String PRODUCT_KEY = "productKey";
    static final String DEVICE_KEY = "deviceKey";

    public static void main(String[] args) {
        // Construct a http connection
        HttpConnection connection = new HttpConnection.Builder(
                BROKER_URL, TOKEN_SERVER_URL, APP_KEY, APP_SECRET, ORG_ID)
            .build();

        DeviceInfo deviceInfo = new DeviceInfo().setAssetId(ASSET_ID);
        // fileUri is an enos scheme file uri
        String fileUri = "enos-connect://xxx.txt";

        try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
            InputStream inputStream = connection.downloadFile(deviceInfo, fileUri, FileCategory.FEATURE);
            byte[] buffer = new byte[1024];
            int len;
            while ((len = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, len);
            }
            byte[] data = outputStream.toByteArray();
            System.out.println(new String(data));
        } catch (EnvisionException | IOException e) {
            e.printStackTrace();
        }

        // Asynchronously call the file download request
        try {
            connection.downloadFile(deviceInfo, fileUri, FileCategory.FEATURE, new IFileCallback() {
                @Override
                public void onResponse(InputStream inputStream) throws IOException {
                    System.out.println("download file asynchronously");
                    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
                    byte[] buffer = new byte[1024];
                    int len;
                    while ((len = inputStream.read(buffer)) != -1) {
                        outputStream.write(buffer, 0, len);
                    }
                    byte[] data = outputStream.toByteArray();
                    System.out.println(new String(data));
                }

                @Override
                public void onFailure(Exception failure) {
                    failure.printStackTrace();
                }
            });
        } catch (EnvisionException e) {
            e.printStackTrace();
        }
    }
}