51Degrees Device Detection Java  4.4

Device detection services for 51Degrees Pipeline


The device detection data file contains meta data that can provide additional information about the various records in the data model. This example shows how to access this data and display the values available.

To help navigate the data, it's useful to have an understanding of the types of records that are present:

  • Component - A record relating to a major aspect of the entity making a web request. There are currently 4 components: Hardware, Software Platform (OS), Browser and Crawler.
  • Profile - A record containing the details for a specific instance of a component. An example of a hardware profile would be the profile for the iPhone 13. An example of a platform profile would be Android 12.1.0.
  • Property - Each property will have a specific value (or values) for each profile. An example of a hardware property is 'IsMobile'. An example of a browser property is 'BrowserName'.

The example will output each component in turn, with a list of the properties associated with each component. Some of the possible values for each property are also displayed. There are too many profiles to display, so we just list the number of profiles for each component.

Finally, the evidence keys that are accepted by device detection are listed. These are the keys that, when added to the evidence collection in flow data, could have some impact on the result returned by device detection.

This example is available in full on GitHub.

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package fiftyone.devicedetection.examples.console;
import fiftyone.devicedetection.DeviceDetectionPipelineBuilder;
import fiftyone.devicedetection.cloud.flowelements.DeviceDetectionCloudEngine;
import fiftyone.devicedetection.examples.shared.KeyHelper;
import fiftyone.pipeline.cloudrequestengine.flowelements.CloudRequestEngine;
import fiftyone.pipeline.core.data.EvidenceKeyFilterWhitelist;
import fiftyone.pipeline.core.flowelements.Pipeline;
import fiftyone.pipeline.engines.data.AspectPropertyMetaData;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Map;
import java.util.Spliterator;
import java.util.stream.StreamSupport;
import static fiftyone.common.testhelpers.LogbackHelper.configureLogback;
import static fiftyone.pipeline.util.FileFinder.getFilePath;
public class MetadataCloud {
private static final Logger logger = LoggerFactory.getLogger(GettingStartedOnPrem.class);
public static void main(String[] args) throws Exception {
String resourceKey = args.length > 0 ? args[0]: null;
run(resourceKey, System.out);
public static void run(String resourceKey, OutputStream output) throws Exception {
logger.info("Running MetadataCloud example");
resourceKey = KeyHelper.getOrSetTestResourceKey(resourceKey);
// Build a new on-premise Hash engine with the low memory performance profile.
// Note that there is no need to construct a complete pipeline in order to access
// the meta-data.
// If you already have a pipeline and just want to get a reference to the engine
// then you can use `var engine = pipeline.GetElement<DeviceDetectionHashEngine>();`
try (Pipeline pipeline = new DeviceDetectionPipelineBuilder(LoggerFactory.getILoggerFactory())
.build()) {
PrintWriter writer = new PrintWriter(output);
logger.info("Listing Properties");
outputProperties(pipeline.getElement(DeviceDetectionCloudEngine.class), writer);
// We use the CloudRequestEngine to get evidence key details, rather than the
// DeviceDetectionCloudEngine.
// This is because the DeviceDetectionCloudEngine doesn't actually make use
// of any evidence values. It simply processes the JSON that is returned
// by the call to the cloud service that is made by the CloudRequestEngine.
// The CloudRequestEngine is actually taking the evidence values and passing
// them to the cloud, so that's the engine we want the keys from.
logger.info("Listing Evidence Key Details");
outputEvidenceKeyDetails(pipeline.getElement(CloudRequestEngine.class), writer);
private static void outputEvidenceKeyDetails(CloudRequestEngine engine, PrintWriter output) {
if (engine.getEvidenceKeyFilter() instanceof EvidenceKeyFilterWhitelist) {
// If the evidence key filter extends EvidenceKeyFilterWhitelist then we can
// display a list of accepted keys.
EvidenceKeyFilterWhitelist filter =
(EvidenceKeyFilterWhitelist) engine.getEvidenceKeyFilter();
output.println("Accepted evidence keys:");
for (Map.Entry<String, Integer> entry : filter.getWhitelist().entrySet()){
output.println("\t" + entry.getKey());
} else {
output.format("The evidence key filter has type " +
"%s. As this does not extend " +
"EvidenceKeyFilterWhitelist, a list of accepted values cannot be " +
"displayed. As an alternative, you can pass evidence keys to " +
"filter.include(string) to see if a particular key will be included " +
"or not.\n", engine.getEvidenceKeyFilter().getClass().getName());
output.println("For example, header.user-agent " +
(engine.getEvidenceKeyFilter().include("header.user-agent") ?
"is " : "is not ") + "accepted.");
private static void outputProperties(DeviceDetectionCloudEngine engine, PrintWriter output) {
Spliterator<AspectPropertyMetaData> spliterator = engine.getProperties().spliterator();
.forEach(property-> {
// Output some details about the property.
// If we're outputting to console then we also add some formatting to make it
// more readable.
output.format(" Property - %s [Category: %s] (%s)\n",