Retrieving a Dataset Aspect in Java using DataHub API

Original Slack Thread

<@U06TM7M40RK> in Java, how do I get an aspect of a Dataset?

To retrieve an aspect of a Dataset in Java using DataHub, you can utilize the DataHub API to fetch versioned aspects. Here’s a general approach based on the available data sources:

  1. Identify the Dataset URN: You need the unique resource name (URN) of the dataset for which you want to fetch the aspect.

  2. Specify the Aspect Name: Determine the name of the aspect you want to retrieve. For example, “schemaMetadata” is a common aspect for datasets.

  3. Use the DataHub API: You can use the DataHub API to fetch the aspect. The API endpoint for fetching a versioned aspect is /aspects. You will need to provide the dataset URN, the aspect name, and optionally the version number.

Here is an example of how you might perform this operation using a curl command, which you can translate into Java using an HTTP client library:

curl 'http://localhost:8080/aspects/urn%3Ali%3Adataset%3A(urn%3Ali%3AdataPlatform%3Afoo%2Cbar%2CPROD)?aspect=schemaMetadata&version=0'

This command fetches the latest version of the “schemaMetadata” aspect for the specified dataset URN.

For a Java implementation, you would typically use an HTTP client to make a GET request to the DataHub API. Here’s a basic example using Java’s HttpURLConnection:

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class DataHubClient {
    public static void main(String[] args) {
        try {
            String datasetUrn = "urn:li:dataset:(urn:li:dataPlatform:foo,bar,PROD)";
            String aspectName = "schemaMetadata";
            String urlString = "http://localhost:8080/aspects/" + 
                               java.net.URLEncoder.encode(datasetUrn, "UTF-8") + 
                               "?aspect=" + aspectName + "&version=0";
            URL url = new URL(urlString);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");

            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String inputLine;
            StringBuilder content = new StringBuilder();
            while ((inputLine = in.readLine()) != null) {
                content.append(inputLine);
            }
            in.close();
            conn.disconnect();

            System.out.println("Aspect Data: " + content.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

This code snippet demonstrates how to make a GET request to the DataHub API to retrieve the specified aspect of a dataset.

Would you like more detailed guidance on any specific part of this process?

Sources:

Hi <@U064583E403>, how did my answer work out for you? Need any more assistance? You can also tag <@U07FV3UHE4D> to let your fellow community members know you’re still looking for guidance.

Hi :slight_smile: ! Did this interaction resolve your issue or do you still require assistance ?

Please tag @ RunLLM if you still need further assistance !

Or tag @Datahub Community Support if you require a person to take a look :slight_smile:

Hope this helps ! ><