Support and Documentation

HttpEndpointDatabase allows you to integrate with a third-party service that uses an HTTP API. A subclass of HttpEndpointDatabase can convert Data queries to HTTP API calls and return the results as if they were retrieved from the Dari underlying database. The search experience is the same for the end user, whether a query is on the underlying database or converted to an HTTP request to a third-party API.

HttpEndpointDatabase includes methods for extracting Dari query predicates and values for constructing HTTP API calls. It also includes methods that you can override to open and close connections to a third-party service, and to save objects to the underlying Dari database.

An HttpEndpointDatabase subclass must implement the doInitialize and readPartial methods inherited from the Dari AbstractDatabase and Database classes, respectively.

The following example shows a simple implementation of HttpEndpointDatabase that leverages the Getty REST Search API to retrieve images from that service. The GettyDatabase class gets the predicate and associated values from a Dari query, constructs an HTTP request that is sent to the Getty API, and returns the Getty response as a Dari PaginatedResult object.

public class GettyDatabase extends HttpEndpointDatabase {

    private static final Logger LOGGER = LoggerFactory.getLogger(GettyDatabase.class);
    public static final String API_KEY_SUB_SETTING = "apiKey"; 1
    public static final String API_URL_SUB_SETTING = "apiUrl";
    public static final String DEFAULT_API_URL = "https://api.gettyimages.com/v3";

    private String apiUrl;
    private String apiKey;

    public String getApiUrl() {
        return apiUrl;
    }

    public void setApiUrl(String apiUrl) {
        this.apiUrl = apiUrl;
    }

    public String getApiKey() {
        return apiKey;
    }

    public void setApiKey(String apiKey) {
        this.apiKey = apiKey;
    }

    @Override 2
    protected void doInitialize(String settingsKey, Map<String, Object> settings) {
        setApiUrl(ObjectUtils.to(String.class, settings.get(API_URL_SUB_SETTING)));
        setApiKey(ObjectUtils.to(String.class, settings.get(API_KEY_SUB_SETTING)));
    }

    @Override /* Must be implemented */
    public <T> PaginatedResult<T> readPartial(Query<T> query, long offset, int limit) {

        String apiKey = getApiKey(); 3
        if (apiKey == null) {
            return PaginatedResult.empty();
        }

        try {
            String apiUrl = ObjectUtils.firstNonBlank(getApiUrl(), DEFAULT_API_URL); 4
            Predicate predicate = query.getPredicate(); 5

            final String fields = "id,title,display_set"; 6

            URL url = new URL(StringUtils.addQueryParameters(apiUrl + "/search/images", 7
                     "phrase", findQueryStringPredicateValue(predicate),
                     "fields", fields,
                     "page", offset + 1,
                     "page_size", limit));

 
            HttpClient httpClient = HttpClientBuilder.create().build(); 8
            HttpGet get = new HttpGet(url.toString());
            get.addHeader("Api-Key", apiKey);
            HttpResponse response = httpClient.execute(get);

            if (response == null) return PaginatedResult.empty();

            Map<String, Object> responseMap = (Map<String, Object>) ObjectUtils
                .fromJson(EntityUtils.toString(response.getEntity())); 9
            List<Object> images = ((List<Object>) responseMap.get("images"));

            if (images != null) { 10
                List<Object> items = images.stream()
                     .map(image -> (Map<String, Object>) image)
                     .filter(Objects::nonNull)
                     .collect(Collectors.toList());

                return Optional.ofNullable((Long) responseMap.get("result_count"))
                     .map(count -> new PaginatedResult(offset, limit, count, items))
                     .orElse(new PaginatedResult(offset, limit, items));
            }
            else return PaginatedResult.empty();

        } catch (IOException error) {
            LOGGER.error("Unable to perform Getty request!", error);
        }
        return PaginatedResult.empty();
    }
}

public class GettyDatabaseProvider implements SourceDatabaseProvider {

    @Override
    public Database get(ObjectType type) {
        GettyDatabase db = new GettyDatabase();
        db.setEnvironment(Database.Static.getDefault().getEnvironment());
        db.setApiKey(Application.Static.getInstance(CmsTool.class).as(GettySettings.class).getApiKey());
        return db;
    }
}