Java SDK

Integrate the Kameleoon Java SDK to run experiments and activate feature flags on Java EE or Jakarta EE application servers.

With the Kameleoon Java SDK, you can run experiments and activate feature flags on your Java EE / Jakarta EE application server.

Getting started: For help getting started, see the developer guide

Changelog: Latest version of the Java SDK: 4.22.0 Changelog.

SDK methods: For the full reference documentation of the Java SDK, see the reference section.

Developer guide

This guide is designed to help you integrate our SDK in a few minutes and start running experiments in your Java applications.

Getting started

Starter kit

To help with getting started, Kameleoon provides a starter kit and demo application to test the SDK. The starter kit includes a fully configured app with examples demonstrating how SDK methods can be used in an app. The starter kit, demo application, and detailed instructions are available at Starter kit for Java

Install the Java client

The installation package is available on the Maven Central repository. You can install the Java SDK by adding a dependency into your project’s pom.xml file, as shown in the example to the right. If you’re using another project management system, see the integrations page for additional examples.

Java EE

pom.xml

<dependency>
  <groupId>com.kameleoon</groupId>
  <artifactId>kameleoon-client-java</artifactId>
  <version>4.16.0</version>
</dependency>

Jakarta EE

pom.xml

<dependency>
  <groupId>com.kameleoon</groupId>
  <artifactId>kameleoon-client-java-jakarta</artifactId>
  <version>4.16.0</version>
</dependency>

Additional configuration

Create a .properties configuration file to provide credentials and customize SDK behavior. You can also download our sample configuration file.

We recommend saving this file to the default path, /etc/kameleoon/client-java.conf, but you can save it anywhere in the classpath as kameleoon-client-java.properties.

The following table shows the available properties that you can set:

Key	Description	Default value
clientId / client_id required	Required for authentication to the Kameleoon service. To find your client_id, see the API credentials documentation.
clientSecret / client_secret required	Required for authentication to the Kameleoon service. To find your client_secret, see the API credentials documentation.
sessionDuration / session_duration_minute optional	Designates the predefined time interval that Kameleoon stores the visitor and their associated data in memory (RAM). Note that increasing the session duration increases the amount of RAM that needs to be allocated to store visitor data.	30 minutes
refreshInterval / refresh_interval_minute optional	Specifies the refresh interval, in minutes, that the SDK fetches the configuration for the active experiments and feature flags. The value determines the maximum time it takes to propagate changes, such as activating or deactivating feature flags or launching experiments, to your production servers. Additionally, we offer a streaming mode that uses server-sent events (SSE) to push new configurations to the SDK automatically and apply new configurations in real-time, without any delays.	60 minutes
defaultTimeout / default_timeout_millisecond optional	Specifies the timeout, in milliseconds, for network requests from the SDK. Set the value to 30 seconds or more if you do not have a stable connection. Some methods have an additional parameter that you can use to override the default timeout for that particular method. If you do not specify the timeout for a method explicitly, the SDK uses this default value.	10000 milliseconds
trackingInterval / tracking_interval_millisecond optional	Specifies the interval for tracking requests in milliseconds. All visitors who Kameleoon evaluated for any feature flag or had data flushed are included in this tracking request, which the SDK performs once per interval. The minimum value is 1000 ms, which is also the default, and the maximum value is 5000 ms.	1000 milliseconds
environment / environment optional	Environment from which the feature flag’s configuration is to be used. The value can be production, staging, development. See the managing environments article for details.	production
topLevelDomain / top_level_domain (required in hybrid mode)	The current top-level domain for your website . Use the format: example.com. Don’t include https://, www, or other subdomains. Kameleoon uses this information to set the corresponding cookie on the top-level domain.	null
proxyHost / proxy_host optional	Sets the proxy host for all outgoing server calls made by the SDK.	null
networkDomain / network_domain optional	Custom domain used by SDKs for outgoing requests, often for proxying. Must be a valid domain (e.g., example.com or sub.example.com). Invalid formats default to Kameleoon’s value.	null

Initialize the Kameleoon client

After you’ve installed the SDK into your application and configured your credentials and SDK behavior (in /etc/kameleoon/client-java.conf), the next step is creating the Kameleoon client in your application code. For example:

import com.kameleoon.KameleoonClientFactory;

String siteCode = "a8st4f59bj";

try {
    KameleoonClient kameleoonClient = KameleoonClientFactory.create(siteCode, "custom/file/path/client-java.properties");
} catch (KameleoonException.SiteCodeIsEmpty e) {
    // indicates that provided site code is empty
} catch (KameleoonException.ConfigCredentialsInvalid exception) {
    // indicates that provided clientId / clientSecret are not valid
}

try {
    KameleoonClientConfig config = new KameleoonClientConfig.Builder()
    .clientId("<clientId>") // mandatory
    .clientSecret("<clientSecret>") // mandatory
    .refreshInterval(60) // in minutes, optional (60 minutes by default)
    .sessionDuration(30) // in minutes, optional (30 minutes by default)
    .defaultTimeout(10_000) // in milliseconds, optional (10000 ms by default)
    .trackingInterval(1000) // in milliseconds, optional (1000 ms by default)
    .topLevelDomain("example.com") // mandatory if you use hybrid mode (engine or web experiments)
    .environment("development") // optional
    .proxyHost(new HttpHost("192.168.0.25", 8080, "http")) // optional
    .networkDomain("example.com") // optional
    .build();
    KameleoonClientFactory.create(siteCode, config);
} catch (KameleoonException.SiteCodeIsEmpty e) {
    // indicates that provided site code is empty
} catch (KameleoonException.ConfigCredentialsInvalid exception) {
    // indicates that provided clientId / clientSecret are not valid
}

A KameleoonClient is a singleton object that bridges your application and the Kameleoon platform. It includes all the methods and properties you need to run an experiment. Note that we also support the use of an HTTP proxy in the Java SDK (see the create() method reference for details).

It’s your responsibility to ensure the proper logic of your application code within the context of A/B testing via Kameleoon. A good practice is to always assume that you can exclude the current visitor from the experiment if you haven’t launched the experiment. This exclusion is simple because it corresponds to the implementation of the default and reference variation logic.

You’re now ready to begin creating and implementing experiments and feature flagging.

Activating a feature flag

Assigning a unique ID to a user

To assign a unique ID to a user, you can use the getVisitorCode() method. If a visitor code doesn’t exist (from the request headers cookie), the method generates a random unique ID or uses a defaultVisitorCode that you would have generated. The ID is then set in a response headers cookie.

If you are using Kameleoon in Hybrid mode, calling the getVisitorCode() method ensures that the unique ID (visitor code) is shared between the application file engine.js (previously named, kameleoon.js) and the SDK.

Retrieving a flag configuration

To implement a feature flag in your code, you must first create the feature flag in your Kameleoon account.

To determine the status or variation of a feature flag for a specific user, you should use the getVariation() or isFeatureActive() method to retrieve the configuration based on the featureKey.

The getVariation() method handles both simple feature flags with ON/OFF states and more complex flags with multiple variations. The method retrieves the appropriate variation for the user by checking the feature rules, assigning the variation, and returning it based on the featureKey and visitorCode.

The isFeatureActive() method can be used if you want to retrieve the configuration of a simple feature flag that has only an ON or OFF state, as opposed to more complex feature flags with multiple variations or targeting options.

If your feature flag has associated variables (such as specific behaviors tied to each variation) getVariation() also enables you to access the Variation object, which provides details about the assigned variation and its associated experiment. This method checks whether the user is targeted, finds the visitor’s assigned variation, and saves it to storage. When track=true, the SDK will send the exposure event to the specified experiment on the next tracking request, which is automatically triggered based on the SDK’s tracking_interval_millisecond. By default, this interval is set to 1000 milliseconds (1 second).

The getVariation() method allows you to control whether tracking is done. If track=false, no exposure events will be sent by the SDK. This is useful if you prefer not to track data through the SDK and instead rely on client-side tracking managed by the Kameleoon engine, for example. Additionally, setting track=false is helpful when using the getVariations() method, where you might only need the variations for all flags without triggering any tracking events. If you want to know more about how tracking works, view this article

Adding data points to target a user or filter / breakdown visits in reports

To target a user, ensure you’ve added relevant data points to their profile before retrieving the feature variation or checking if the flag is active. Use the addData() method to add these data points to the user’s profile.

To retrieve data points collected on other devices or to access past user data (collected client-side when using Kameleoon in Hybrid mode), use the getRemoteVisitorData() method. This method asynchronously fetches data from the servers. It is important to call getRemoteVisitorData() before retrieving the variation or checking if the feature flag is active, as this data might be required to assign a user to a given variation.

To learn more about available targeting conditions, see the detailed article on the subject.

Additionally, the data points you add to the visitor profile will be available when analyzing your experiments, allowing you to filter and break down your results by factors like device and browser. Kameleoon Hybrid mode automatically collects a variety of data points on the client-side, making it easy to break down your results based on these pre-collected data points. See the complete list here.

If you need to track additional data points beyond what’s automatically collected, you can use Kameleoon’s Custom Data feature. Custom Data allows you to capture and analyze specific information relevant to your experiments. Don’t forget to call the flush() method to send the collected data to Kameleoon servers for analysis.

To ensure your results are accurate, it’s recommended to filter out bots by using the UserAgent data type.

Tracking goal conversions

When a user completes a desired action (such as making a purchase), it is recorded as a conversion. To track conversions, use the trackConversion() method and provide the required visitorCode and goalId parameters.

The conversion tracking request will be sent along with the next scheduled tracking request, which the SDK sends at regular intervals (defined by tracking_interval_millisecond). If you prefer to send the request immediately, use the flush() method with the parameter instant=true.

Sending events to analytics solutions

To track conversions and send exposure events to your customer analytics solution, you must first implement Kameleoon in Hybrid mode. Then, use the getEngineTrackingCode() method.

The getEngineTrackingCode() method retrieves the unique tracking code required to send exposure events to your analytics solution. Using this method allows you to record events and send them to your desired analytics platform.

Using a custom bucketing key

By default, Kameleoon uses a unique, anonymous visitor ID (visitorCode) to assign users to feature flag variations. This ID is typically generated and stored on the user’s device (in a browser cookie for client-side and server-side SDKs—in persistent storage for mobile SDKs). However, in certain scenarios you may need to ensure all users of the same organization see the same variant of a feature flag.

The Custom Bucketing Key option allows you to override this default behavior by providing your own custom identifier for bucketing. This override ensures that Kameleoon’s assignment logic uses your specified key instead of the default visitorCode.

Use cases

Using a custom bucketing key is essential for maintaining consistency and accuracy in your feature flag assignments, particularly in these situations:

• Account-level or organizational experiments: For B2B products or scenarios where you want to assign all users from the same organization to the same variation, you can use an identifier like an accountId. Custom bucketing keys are crucial for A/B testing features that impact an entire team or company.

By implementing a custom bucketing key, you ensure greater consistency and accuracy in your experiments, leading to more reliable results and a better user experience.

Technical details

When you configure a custom bucketing key for a feature flag, you provide Kameleoon with a specific identifier from your application’s data:

kameleoonClient.addData(visitorCode, new CustomData(index, "newVisitorCode"));

• Providing the custom key: You provide your custom identifier to the Kameleoon SDK using the addData() method. In this method, you will pass your chosen custom bucketing key as a CustomData object. Here, newVisitorCode refers to the identifier you wish to use for your bucketing (for example, the new userId or accountId).

For the custom bucketing key to function correctly, it must also be defined and configured for the feature flag during the flag creation or editing process. Without this corresponding configuration, the SDK’s bucketing will not apply your custom key. For detailed instructions on how to set this up in Kameleoon, refer to this article.

• Bucketing logic: Once a custom bucketing key is provided through the addData() method, all hash calculations for assigning users to variations will use this newVisitorCode (your custom key) instead of the default visitorCode. Using the newVisitorCode means that the bucketing decision is tied to your custom identifier, ensuring consistent assignments across various contexts where that identifier is present.
• Data tracking and analytics: It’s crucial to note that while the newVisitorCode (your custom key) is used for bucketing decisions, all subsequent data (tracking events and conversions, for example) is sent and associated with the original visitorCode. This separation ensures that your analytics accurately reflect individual user journeys and interactions within your experiment’s broader context, even when bucketing is performed at a higher level (like an account) or across multiple devices/sessions. Your original visitor data remains intact for comprehensive reporting.

Technical requirements

To effectively use a custom bucketing key:

• The key must be a String.
• It must be unique for the entity you intend to bucket (for example, if using a userId, each user’s ID should be unique).
• The key must be available to the SDK at the exact moment the feature flag decision is evaluated for that user or request.

Targeting conditions

The Kameleoon SDKs support a variety of predefined targeting conditions that you can use to target users in your campaigns. For the list of conditions this SDK supports, see use visit history to target users.

You can also use your own external data to target users.

Cross-device experimentation

To support visitors who access an app from multiple devices, Kameleoon allows the synchronization of previously collected visitor data across each of the visitor’s devices and reconciliation of their visit history across devices through cross-device experimentation. Case studies and detailed information on how Kameleoon handles data across devices are available in the article on cross-device experimentation.

Synchronizing custom data across devices

Although custom mapping synchronization is used to align visitor data across devices, it is not always necessary. Below are two scenarios where custom mapping sync is not required:

Same user ID across devices If the same user ID is used consistently across all devices, synchronization is handled automatically without a custom mapping sync. It is enough to call the getRemoteVisitorData() method when you want to sync the data collected between multiple devices.

Multi-server instances with consistent IDs In complex setups involving multiple servers (for example, distributed server instances), where the same user ID is available across servers, synchronization between servers (with getRemoteVisitorData()) is sufficient without additional custom mapping sync.

Customers who need additional data can refer to the getRemoteVisitorData() method description for further guidance. In the below code, it is assumed that the same unique identifier (in this case, the visitorCode, which can also be referred to as userId) is used consistently between the two devices for accurate data retrieval.

If you want to sync collected data in real time, you need to choose the scope Visitor for your custom data.

Device A

// In this example, a Custom data with index `90` was set to "Visitor" scope in Kameleoon.
final int VISITOR_SCOPE_CUSTOM_DATA_INDEX = 90;

kameleoonClient.addData(visitorCode, new CustomData(VISITOR_SCOPE_CUSTOM_DATA_INDEX, "your data"));
kameleoonClient.flush(visitorCode);

Device B

// Before working with the data, call the `getRemoteVisitorData` method.
kameleoonClient.getRemoteVisitorData(visitorCode).get();

// After calling the method, the SDK on Device B will have access to CustomData of Visitor scope defined on Device A.
// So, "your data" will be available for targeting and tracking the visitor.

Using custom data for session merging

Cross-device experimentation allows for combining a visitor’s history across each of their devices (history reconciliation). History reconciliation allows merging different visitor sessions into one. To reconcile visit history, use CustomData to provide a unique identifier for the visitor. For more information, see the dedicated documentation.

After cross-device reconciliation is enabled, calling getRemoteVisitorData() with the parameter userId retrieves all known data for a given user.

Sessions with the same identifier will always be shown the same variation in an experiment. In the Visitor view of your experiment’s results pages, these sessions will appear as a single visitor.

The SDK configuration ensures that associated sessions always see the same variation of the experiment. However, there are some limitations regarding cross-device variation allocation. These limitations are outlined here.

Follow the activating cross-device history reconciliation guide to set up your custom data on the Kameleoon platform.

Afterwards, you can use the SDK normally. The following methods that may be helpful in the context of session merging:

• getRemoteVisitorData() with added UniqueIdentifier(true) - to retrieve data for all linked visitors.
• trackConversion() or flush() with added UniqueIdentifier(true) data - to track some data for specific visitor that is associated with another visitor.

As the custom data you use as the identifier must be set to Visitor scope, you need to use cross-device custom data synchronization to retrieve the identifier with the getRemoteVisitorData() method on each device.

Here’s an example of how to use custom data for session merging.

// In this example, 91 represents the Custom Data's index configured as a unique identifier in Kameleoon.
final int MAPPING_INDEX = 91;
final String FEATURE_KEY = "ff123";

// 1. Before the visitor is authenticated

// Retrieve the variation for an unauthenticated visitor.
// Assume anonymousVisitorCode is the randomly generated ID for that visitor.
Variation anonymousVariation = kameleoonClient.getVariation(anonymousVisitorCode, FEATURE_KEY);

// 2. After the visitor is authenticated

// Assume `userId` is the visitor code of the authenticated visitor.
kameleoonClient.addData(anonymousVisitorCode, new CustomData(MAPPING_INDEX, userId));
kameleoonClient.flush(true, anonymousVisitorCode);

// Indicate that `userId` is a unique identifier.
kameleoonClient.addData(userId, new UniqueIdentifier(true));

// 3. After the visitor was authorized

// Retrieve the variation for the `userId`, which will match the anonymous visitor code's variation.
Variation userVariation = kameleoonClient.getVariation(userId, FEATURE_KEY);
boolean isSameVariation = userVariation.getKey().equals(anonymousVariation.getKey()); // true

// `userId` and `anonymousVisitorCode` are now linked and can be tracked as a single visitor.
kameleoonClient.trackConversion(userId, 123, 10.0);

// Additionally, the linked visitors share all fetched previously tracked remote data.
kameleoonClient.getRemoteVisitorData(userId).get();

In this example, the application has a login page. Since the user ID is unknown at the moment of login, an anonymous visitor identifier generated by the getVisitorCode() method is used. After the user logs in, the anonymous visitor is associated with the user ID and used as a unique identifier for the visitor.

Logging

The SDK generates logs to reflect various internal processes and issues.

Log levels

The SDK supports configuring limiting logging by a log level.

// The `NONE` log level does not allow logging.
com.kameleoon.logging.KameleoonLogger.setLogLevel(com.kameleoon.logging.LogLevel.NONE);

// The `ERROR` log level only allows logging issues that may affect the SDK's primary behaviour.
com.kameleoon.logging.KameleoonLogger.setLogLevel(com.kameleoon.logging.LogLevel.ERROR);

// The `WARNING` log level allows logging issues which may require an attention.
// It extends the `ERROR` log level.
// The `WARNING` log level is a default log level.
com.kameleoon.logging.KameleoonLogger.setLogLevel(com.kameleoon.logging.LogLevel.WARNING);

// The `INFO` log level allows logging general information on the SDK's internal processes.
// It extends the `WARNING` log level.
com.kameleoon.logging.KameleoonLogger.setLogLevel(com.kameleoon.logging.LogLevel.INFO);

// The `DEBUG` level logs additional details about the SDK’s internal processes and extends the `INFO` level
// with more granular diagnostic output.
// This information is not intended for end-user interpretation but can be sent to our support team
// to assist with internal troubleshooting.
com.kameleoon.logging.KameleoonLogger.setLogLevel(com.kameleoon.logging.LogLevel.DEBUG);

Custom handling of logs

The SDK writes its logs to the console output by default. This behaviour can be overridden.

Logging limiting by a log level is performed apart from the log handling logic.

public class CustomLogger implements com.kameleoon.logging.Logger {
    private final java.util.logging.Logger inner;

    public CustomLogger(java.util.logging.Logger inner) {
        this.inner = inner;
    }

    // `log` method accepts logs from the SDK
    @Override
    public void log(com.kameleoon.logging.LogLevel level, String message) {
        // Custom log handling logic here. For example:
        switch (level) {
            case ERROR:
                inner.log(java.util.logging.Level.SEVERE, message);
                break;
            case WARNING:
                inner.log(java.util.logging.Level.WARNING, message);
                break;
            case INFO:
                inner.log(java.util.logging.Level.INFO, message);
                break;
            case DEBUG:
                inner.log(java.util.logging.Level.FINE, message);
                break;
        }
    }
}

// Log level filtering is applied separately from log handling logic.
// The custom logger will only accept logs that meet or exceed the specified log level.
// Ensure the log level is set correctly.
com.kameleoon.logging.KameleoonLogger.setLogLevel(com.kameleoon.logging.LogLevel.DEBUG); // Optional; defaults to `LogLevel.WARNING`.
com.kameleoon.logging.KameleoonLogger.setLogger(new CustomLogger());

Reference

This is the full reference documentation for the Java SDK.

Initialization

create()

To use the SDK, you must finish initialization. Your app conducts all interactions with the SDK through an object of the KameleoonClient class. Create this object using the static method create() in KameleoonClientFactory.

import com.kameleoon.KameleoonClientFactory;

String siteCode = "a8st4f59bj";

try {
    KameleoonClient kameleoonClient = KameleoonClientFactory.create(siteCode, "custom/file/path/client-java.properties");
} catch (KameleoonException.SiteCodeIsEmpty e) {
    // indicates that provided site code is empty
} catch (KameleoonException.ConfigCredentialsInvalid exception) {
    // indicates that provided clientId / clientSecret are not valid
}

try {
    KameleoonClientConfig config = new KameleoonClientConfig.Builder()
        .clientId("<clientId>") // mandatory
        .clientSecret("<clientSecret>") // mandatory
        .refreshInterval(60) // in minutes, optional (60 minutes by default)
        .sessionDuration(30) // in minutes, optional (30 minutes by default)
        .defaultTimeout(10_000) // in milliseconds, optional (10000 ms by default)
        .trackingInterval(1000) // in milliseconds, optional (1000 ms by default)
        .topLevelDomain("example.com") // mandatory if you use hybrid mode (engine or web experiments)
        .environment("development") // optional
        .proxyHost(new HttpHost("192.168.0.25", 8080, "http")) // optional
        .networkDomain("example.com") // optional
        .build();
    KameleoonClientFactory.create(siteCode, config);
} catch (KameleoonException.SiteCodeIsEmpty e) {
    // indicates that provided site code is empty
} catch (KameleoonException.ConfigCredentialsInvalid exception) {
    // indicates that provided clientId / clientSecret are not valid
}

Parameters

Name	Type	Description	Default value
siteCode required	String	This is a unique key of the Kameleoon project you are using with the SDK.
configurationPath optional	String	Path to the SDK configuration file.	/etc/kameleoon/client-java.conf
kameleoonConfig optional	KameleoonClientConfig	Configuration SDK object that you can pass instead of using a configuration file.	null

Return value

Type	Description
KameleoonClient	An instance of the KameleoonClient class that your app can then use to manage your experiments and feature flags.

Exceptions thrown

Type	Description
KameleoonException.ConfigCredentialsInvalid	Exception indicating that the requested credentials were not provided (either in the configuration file or as arguments to the method).
KameleoonException.SiteCodeIsEmpty	Exception indicating that the specified site code is empty string which is invalid value.

waitInit()

waitInit() awaits the initialization of the KameleoonClient. This method allows you to check if the SDK has successfully initialized the client before proceeding with other operations.

If the waitInit() method fails, the initialization process will continue without interruption. Subsequent calls to the waitInit() method will return results that reflect the current state of the KameleoonClient. Thus, you can invoke the waitInit() method multiple times to check the status of the SDK.

// Synchronized approach
try {
    kameleoonClient.waitInit().get();
} catch (InterruptedException | ExecutionException exception) {
    // Indicates that the client could not be initialized due to the thrown exception.
}

// Asynchronous approach
kameleeoonClient.waitInit().handle((res, ex) -> {
    if (ex != null) {
        // Indicates that the client could not be initialized due to the thrown exception.
    }
    return res;
});

Return value

Type	Description
CompletableFuture<Void>	The task will complete when the client has been successfully initialized.

Exceptions thrown

Type	Description
SDKNotReady	Exception indicating that client is not initialized properly and cannot be used yet.

isReady()

isReady() checks whether the SDK is ready for use, i.e. its configuration has been successfully loaded. Unlike waitInit(), this method returns immediately without blocking or throwing.

Readiness is monotonic: once the SDK becomes ready it stays ready. Even if a later configuration refresh fails, the SDK keeps using the previously downloaded configuration, so it never reverts to a not-ready state.

boolean ready = kameleoonClient.isReady();

Return value

Type	Description
boolean	true if the SDK has been successfully initialized; false otherwise (including while initialization is still pending or has failed).

Feature flags and variations

isFeatureActive()

• 📨 Sends Tracking Data to Kameleoon (depending on the track parameter)

This method was previously called activeFeature, which was removed in SDK version 4.0.0.

Call this method to check whether a feature flag should be active for a specified user. This method takes a visitorCode and a featureKey as mandatory arguments to check if the feature is active for the user.

If the user has never been associated with this feature flag, the SDK returns a random boolean value (either true to add the user to this feature or false to exclude them from the feature). If a user with the specified visitorCode is already registered with this feature flag, the SDK detects the previous featureFlagvalue.

Make sure you catch and handle potential exceptions.

If you specify a visitorCode, the isFeatureActive() method uses it as the unique visitor identifier, which is useful for Cross-device experimentation. When you specify a visitorCode and set the isUniqueIdentifier parameter to true, the SDK links the flushed data with the visitor associated with the specified identifier.

The parameter isUniqueIdentifier is deprecated. Please use UniqueIdentifier instead.

The isUniqueIdentifier can be helpful in unique situations; for example, if you cannot access the anonymous visitorCode given to a visitor, but you can use an internal ID linked to that visitor through session merging.

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
String featureKey = "new_checkout";
Boolean hasNewCheckout = false;

try {
  hasNewCheckout = kameleoonClient.isFeatureActive(visitorCode, featureKey);
  // disabling tracking
  hasNewCheckout = kameleoonClient.isFeatureActive(false, visitorCode, featureKey);
} catch (KameleoonException.FeatureNotFound e) {
  // Feature toggle not yet activated on Kameleoon's side - we consider the feature inactive.
  hasNewCheckout = false;
} catch (Exception e) {
  // This is a generic exception handler that handles all exceptions.
  System.out.println("Exception occurred");
}
if (hasNewCheckout)
{
  // Implement new checkout code here
}

Parameters

Name	Type	Description
track	boolean	An optional parameter to enable or disable tracking of the feature evaluation (true by default).
visitorCode	String	Unique identifier of the user. This field is required.
featureKey	String	Key of the feature that you want to check the status of for the user. This field is required.
isUniqueIdentifier (Deprecated)	boolean	An optional parameter for specifying if the visitorCode is a unique identifier. If not provided, the default value is false. The field is optional.

Return value

Type	Description
boolean	Value of the feature that is registered for the specified visitorCode.

Exceptions thrown

Type	Description
KameleoonException.FeatureNotFound	Exception indicating that the requested feature ID wasn’t found in the SDK’s internal configuration. This exception usually means that the feature flag has not yet been activated on Kameleoon’s side (but code that implements the feature is already deployed in the application).
KameleoonException.VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.

getVariation()

• 📨 Sends Tracking Data to Kameleoon (depending on the track parameter)

Retrieves the Variation assigned to a given visitor for a specific feature flag.

This method takes a visitorCode and featureKey as mandatory arguments. The track argument is optional and defaults to true.

It returns the assigned Variation for the visitor. If the visitor is not associated with any feature flag rules, the method returns the default Variation for the given feature flag.

Ensure that proper error handling is implemented in your code to manage potential exceptions.

The default variation refers to the variation assigned to a visitor when they do not match any predefined delivery rules for a feature flag. In other words, it is the fallback variation applied to all users who are not targeted by specific rules. It’s represented as the variation in the “Then, for everyone else…” section in a management interface.

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
String featureKey = "new_checkout";
Variation variation;

try {
  variation = kameleoonClient.getVariation(visitorCode, featureKey);
  // disabling tracking
  variation = kameleoonClient.getVariation(visitorCode, featureKey, false);
} catch (KameleoonException.FeatureNotFound e) {
  // The error has occurred; the feature flag isn't found in the current configuration.
} catch (KameleoonException.FeatureEnvironmentDisabled e) {
  // The feature flag is disabled for the environment.
} catch (KameleoonException.VisitorCodeInvalid e) {
  // The visitor code you passed to the method is invalid and can't be accepted by SDK.
} catch (KameleoonException ex) {
  // Handle the common Kameleoon Exception
}

// Fetch a variable value for the assigned variation
String title = (String) variation.getVariables().get("title").getValue();

switch (variation.getKey()) {
  case 'on':
    // Main variation key is selected for visitorCode
    break;
  case 'alternative_variation':
    // Alternative variation key
    break;
  default:
    // Default variation key
    break;
}

Parameters

Name	Type	Description	Default
visitorCode required	String	Unique identifier of the visitor.
featureKey required	String	Key of the feature you want to expose to a visitor.
track optional	boolean	An optional parameter to enable or disable tracking of the feature evaluation.	true

Return value

Type	Description
Variation	An assigned Variation to a given visitor for a specific feature flag.

Exceptions thrown

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.
FeatureNotFound	Exception indicating that the requested feature key wasn’t found in the internal configuration of the SDK. This usually means that the feature flag is not activated in the Kameleoon app (but code implementing the feature is already deployed in the application).
FeatureEnvironmentDisabled	Exception indicating that feature flag is disabled for the visitor’s current environment (for example, production, staging, or development).

getVariations()

• 📨 Sends Tracking Data to Kameleoon (depending on the track parameter)

Retrieves a map of Variation objects assigned to a given visitor across all feature flags.

This method iterates over all available feature flags and returns the assigned Variation for each flag associated with the specified visitor. It takes visitorCode as a mandatory argument, while onlyActive and track are optional.

• If onlyActive is set to true, the method getVariations() will return feature flags variations provided the user is not bucketed with the off variation.
• The track parameter controls whether or not the method will track the variation assignments. By default, it is set to true. If set to false, the tracking will be disabled.

The returned map consists of feature flag keys as keys and their corresponding Variation as values. If no variation is assigned for a feature flag, the method returns the default Variation for that flag.

Proper error handling should be implemented to manage potential exceptions.

The default variation refers to the variation assigned to a visitor when they do not match any predefined delivery rules for a feature flag. In other words, it is the fallback variation applied to all users who are not targeted by specific rules. It’s represented as the variation in the “Then, for everyone else…” section in a management interface.

try {
    Map<String, Variation> variations = kameleoonClient.getVariations(visitorCode);
    // only active variations
    Map<String, Variation> variations = kameleoonClient.getVariations(visitorCode, true);
    // disable tracking
    Map<String, Variation> variations = kameleoonClient.getVariations(visitorCode, true, false);
} catch (VisitorCodeInvalid e) {
    //  Handle exception
}

Parameters

Name	Type	Description	Default
visitorCode required	String	Unique identifier of the visitor.
onlyActive optional	boolean	An optional parameter indicating whether to return variations for active (true) or all (false) feature flags.	false
track optional	boolean	An optional parameter to enable or disable tracking of the feature evaluation.	true

Return value

Type	Description
Map<String, Variation>	Map that contains the assigned Variation objects of the feature flags using the keys of the corresponding features.

Exceptions thrown

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.

setForcedVariation()

The method allows you to programmatically assign a specific Variation to a user, bypassing the standard evaluation process. This is especially valuable for controlled experiments where the usual evaluation logic is not required or must be skipped. It can also be helpful in scenarios like debugging or custom testing.

When a forced variation is set, it overrides Kameleoon’s real-time evaluation logic. Processes like segmentation, targeting conditions, and algorithmic calculations are skipped. To preserve segmentation and targeting conditions during an experiment, set forceTargeting=false instead.

Simulated variations always take precedence in the execution order. If a simulated variation calculation is triggered, it will be fully processed and completed first.

A forced variation is treated the same as an evaluated variation. It is tracked in analytics and stored in the user context like any standard evaluated variation, ensuring consistency in reporting.

The method may throw exceptions under certain conditions (e.g., invalid parameters, user context, or internal issues). Proper exception handling is essential to ensure that your application remains stable and resilient.

It’s important to distinguish forced variations from simulated variations:

• Forced variations: Are specific to an individual experiment.
• Simulated variations: Affect the overall feature flag result.

try {
    // Forcing the variation "on" for the feature flag "featureKey1" for the visitor
    final int experimentId = 9516;
    kameleoonClient.setForcedVariation(visitorCode, experimentId, "on");

    // Resetting the forced variation for the feature flag "featureKey1" for the visitor
    kameleoonClient.setForcedVariation(visitorCode, experimentId, null);
} catch (KameleoonException ex) {
    // Handle the common Kameleoon Exception
}

Parameters

Name	Type	Description	Default
visitorCode required	String	Unique identifier of the visitor.
experimentId required	int	Experiment Id that will be targeted and selected during the evaluation process.
variationKey required	String	Variation Key corresponding to a Variation that should be forced as the returned value for the experiment. If the value is null, the forced variation will be reset.
forceTargeting optional	boolean	Indicates whether targeting for the experiment should be forced and skipped (true) or applied as in the standard evaluation process (false).	true

Exceptions thrown

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.
FeatureExperimentNotFound	Exception indicating that the requested experiment id has not been found in the SDK’s internal configuration. This is usually normal and means that the rule’s corresponding experiment has not yet been activated on Kameleoon’s side.
FeatureVariationNotFound	Exception indicating that the requested variation key(id) has not been found in the internal configuration of the SDK. This is usually normal and means that the variation’s corresponding experiment has not yet been activated on Kameleoon’s side.

In most cases, only the basic error, KameleoonException, needs to be handled, as demonstrated in the example. However, if different types of errors require a response, handle each one separately based on specific requirements. Additionally, for enhanced reliability, general language errors can be handled by including Exception.

evaluateAudiences()

• 📨 Sends Tracking Data to Kameleoon

This method evaluates visitors against all available Audiences Explorer segments and tracks those who match.

evaluateAudiences() should be called after all relevant visitor data has been set or updated, and just before getting a feature variation or checking a feature flag. This approach ensures that the visitor is evaluated against the most current data available, allowing for accurate audience assignment based on all criteria.

After calling this method, you can perform a detailed analysis of segment performance in Audiences Explorer.

try {
    kameleoonClient.evaluateAudiences(visitorCode);
} catch (KameleoonException ex) {
    // Handle the common Kameleoon Exception
}

Parameters

Name	Type	Description
visitorCode required	String	Unique identifier of the visitor.

Exceptions thrown

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.

In most cases, only the basic error, KameleoonException, needs to be handled, as demonstrated in the example. However, if different types of errors require a response, handle each one separately based on specific requirements. Additionally, for enhanced reliability, general language errors can be handled by including Exception.

getFeatureList()

This method was previously called obtainFeatureList, which was removed in SDK version 4.0.0.

Returns a list of feature flag keys currently available for the SDK.

List<String> allFeatureFlagKey = kameleoonClient.getFeatureList();

Return value

Type	Description
List<String>	List of feature flag keys

getDataFile()

To evaluate all feature flags, use getVariations(). This method is more efficient than calling DataFile and iterating through flags with getVariation().

Returns the current SDK configuration as a DataFile object.

try {
    DataFile dataFile = kameleoonClient.getDataFile();
} catch (Exception e) {
    // Recommended (but optional) safeguard for unexpected exceptions from third-party libraries
}

Return value

Type	Description
DataFile	The DataFile containing the SDK configuration

Visitor data

getVisitorCode()

This method was previously called obtainVisitorCode, which was removed in SDK version 4.0.0.

The getVisitorCode() method should be called to obtain the Kameleoon visitorCode for the current visitor. This method is especially important when using Kameleoon in a mixed front-end and back-end environment, where user identification consistency must be guaranteed. The implementation logic is described here:

1. We check if a kameleoonVisitorCode cookie or query parameter associated with the current HTTP request can be found. If it can, we use this kameleoonVisitorCode as the visitor identifier.

2. If no cookie / parameter is found in the current request, we either randomly generate a new identifier or use the defaultVisitorCode argument as identifier if it is passed. This process allows our customers to use their identifiers as visitor codes, should they wish to. This flexibility has the added benefit of matching Kameleoon visitors with their own users without any additional look-ups in a matching table.

3. Regardless, the server-side (via HTTP header) kameleoonVisitorCode cookie is set with the relevant value. Then, the method returns this identifier value.

For more information, refer to this article.

If you provide a visitorCode, its uniqueness must be guaranteed on your end - the SDK cannot check it. Also, note that the length of visitorCode is limited to 255 characters. Any excess characters will throw an exception.

The getVisitorCode() method allows you to set simulated variations for a visitor. When cookies (from a request or document) contain the key kameleoonSimulationFFData, the standard evaluation process is bypassed. Instead, the method directly returns a Variation based on the provided data.

You can apply simulations in two ways:

• Automatically (recommended): If using Kameleoon Web Experimentation or the SDK in Hybrid mode, the cookie is created automatically when simulating a variant’s display using the Simulation Panel.
• Manually: Set the kameleoonSimulationFFData cookie manually.

It’s important to distinguish simulated variations from forced variations:

• Simulated variations: Affect the overall feature flag result.
• Forced variations: Are specific to an individual experiment.

⚙️ Manual setup

Please ensure the kameleoonSimulationFFData cookie follows this format:

• kameleoonSimulationFFData={"featureKey":{"expId":10,"varId":20}}: Simulates the variation with varId of experiment expId for the given featureKey.
• kameleoonSimulationFFData={"featureKey":{"expId":0}}: Simulates the default variation (defined in the Then, for everyone else in Production, serve section) for the given featureKey.

⚠️ To ensure proper functionality, the cookie value must be encoded as a URI component using a method such as encodeURIComponent.

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse, defaultVisitorCode);

Parameters

Name	Type	Description
httpServletRequest	HttpServletRequest	The current HttpServletRequest object should be passed as the first parameter. This field is mandatory.
httpServletResponse	HttpServletResponse	The current HttpServletResponse object should be passed as the second parameter. This field is mandatory.
defaultVisitorCode	String	This parameter will be used as the visitorCode when an existing kameleoonVisitorCode cookie is not found on the request. This field is optional. If not specified, the SDK generates a random visitorCode when no existing kameleoonVisitorCode cookie.

Return value

Type	Description
String	A visitorCode that will be associated with this particular user and should be used with most of the methods of the SDK.

addData()

The addData() method adds targeting data to storage so other methods can use the data to decide whether or not to target the current visitor.

The addData() method does not return any value and does not interact with Kameleoon back-end servers on its own. Instead, all the declared data is saved for future transmission using the flush() method. This approach reduces the number of server calls made, as the data is typically grouped into a single server call that is triggered by the flush().

The trackConversion() method also sends out any previously associated data, just like the flush(). The same holds true for getVariation() and getVariations() methods if an experimentation rule is triggered.

Each visitor can only have one instance of associated data for most data types. However, CustomData is an exception. Visitors can have one instance of associated CustomData per index.

// Add a single data item (tracked by default)
kameleoonClient.addData(visitorCode, Browser.chrome());

// Add multiple data items (tracked by default)
kameleoonClient.addData(visitorCode, new PageView("https://url.com", "title"), new UserAgent("UserAgent"));

// Add multiple data items stored locally for targeting only (not sent to the Kameleoon Data API)
kameleoonClient.addData(visitorCode, false, new PageView("https://url.com", "title"), new UserAgent("UserAgent"));

Parameters

Name	Type	Description	Default value
visitorCode required	String	Unique identifier of the visitor.
track optional	boolean	Specifies whether the added data is eligible for tracking. When set to false, the data is stored locally and used only for targeting evaluation; it is not sent to the Kameleoon Data API.	true
data required	Data...	Collection of Kameleoon data types.

Exceptions

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.

flush()

• 📨 Sends Tracking Data to Kameleoon

The flush() method collects the Kameleoon data linked to the visitor. It then sends a tracking request, along with all data added using the addData method, which has not yet been sent using one of these methods. flush() is non-blocking as the server call is made asynchronously.

flush allows you to control when data associated with a given visitorCode is sent to our servers. For instance, if you call addData() a dozen times, it would be inefficient to send data to the server each time addData() is invoked. So, all you have to do is call flush() once.

If you specify a visitorCode, the flush() method uses this code as the unique visitor identifier, which is useful for cross-device experimentation. When you specify a visitorCode and set the isUniqueIdentifier parameter to true, the SDK links the flushed data to the visitor associated with the specified identifier.

The parameter isUniqueIdentifier is deprecated. Please use UniqueIdentifier instead.

The isUniqueIdentifier can be helpful in unique situations; for example, if you cannot access the anonymous visitorCode given to a visitor, but you can use an internal ID linked to that visitor through session merging.

try {
    kameleoonClient.flush(visitorCode); // Interval tracking (most performant tracking method)
    kameleoonClient.flush(true, visitorCode); // Instant tracking
} catch (VisitorCodeInvalid e) {
  // Catch exception
}

Parameters

Name	Type	Description
instant	boolean	Boolean flag indicating whether the data should be sent instantly (true) or according to the default tracking interval (false) set with the SDK parameter tracking_interval_millisecond. This field is optional.
visitorCode	String	User’s unique identifier. This field is required.
isUniqueIdentifier (Deprecated)	boolean	An optional parameter for specifying if the visitorCode is a unique identifier. The visitorCode should be provided and not null to apply isUniqueIdentifier for a visitor, otherwise it will be ignored. If not provided, the default value is false. The field is optional.

getRemoteData()

This method was previously called retrieveDataFromRemoteSource, which was removed in SDK version 4.0.0.

The getRemoteData() method allows you to retrieve data (according to a key passed as argument) for the specified siteCode stored on the Kameleoon server. Your site code is specified in KameleoonClientFactory.create(). Usually, data is stored on our remote servers using our Data API. This method, along with the availability of our scalable servers, provides a convenient way to store additional data that you can later retrieve for your app.

CompletableFuture<JsonObject> data = kameleoonClient.getRemoteData("key");

try {
  JsonObject test = kameleoonClient.getRemoteData("key").get(5_000, TimeUnit.MILLISECONDS);
} catch (InterruptedException | ExecutionException | TimeoutException e) {
  // Catch exception
}

Parameters

Name	Type	Description
key	String	The key that is associated with the retrieved data. This field is mandatory.

Return value

Type	Description
CompletableFuture<JsonObject>	Future JsonObject associated with retrieving data for specific key.

getRemoteVisitorData()

getRemoteVisitorData() is an asynchronous method for retrieving Kameleoon Visits Data for the visitorCode from the Kameleoon Data API. The method adds the data to storage for other methods to use when making targeting decisions.

Data obtained using this method plays an important role when you want to:

• use data collected from other devices.
• access a user’s history, such as previously visited pages during past visits.
• use data that is only accessible on the client-side, like datalayer variables and goals that convert on the front-end.

Read this article for a better understanding of possible use cases.

By default, getRemoteVisitorData() automatically retrieves the latest stored custom data with scope=Visitor and attaches them to the visitor without the need to call the method addData(). It is particularly useful for synchronizing custom data between multiple devices.

The parameter isUniqueIdentifier is deprecated. Please use UniqueIdentifier instead.

The isUniqueIdentifier can be helpful in unique situations; for example, if you cannot access the anonymous visitorCode given to a visitor, but you can use an internal ID linked to that visitor through session merging.

String visitorCode = "visitorCode";
// Visitor data will be fetched and automatically added for `visitorCode`
CompletableFuture<List<Data>> visitorData = kameleoonClient.getRemoteVisitorData(visitorCode);

// If you only want to fetch data and add it yourself manually, set addData == `false`
CompletableFuture<List<Data>> visitorData = kameleoonClient.getRemoteVisitorData(visitorCode, false);

// If you want to fetch custom list of data types
RemoteVisitorDataFilter filter = RemoteVisitorDataFilter.builder()
    .previousVisitAmount(25)
    .customData(false)
    .conversions(true)
    .build();
CompletableFuture<List<Data>> visitorData = kameleoonClient.getRemoteVisitorData(visitorCode, filter, true, false);

try {
  List<Data> visitorData = kameleoonClient.getRemoteVisitorData(visitorCode).get(5_000, TimeUnit.MILLISECONDS);
  // Your custom code
} catch (CancellationException | InterruptedException | ExecutionException | TimeoutException e) {
  // Catch exception
}

Parameters

Name	Type	Description
visitorCode	string	The visitor code for the data you want to retrieve. This field is mandatory.
filter	RemoteVisitorDataFilter	Filter for specifying what data should be retrieved from visits. By default, only CustomData is retrieved from the current and latest previous visit (RemoteVisitorDataFilter.builder().build() or new RemoteVisitorDataFilter()). Other filters parameters are set to false. This field is optional.
addData	boolean	A boolean indicating whether the method should automatically add retrieved data for a visitor. This field is optional.
isUniqueIdentifier (Deprecated)	boolean	An optional parameter for specifying if the visitorCode is a unique identifier. If not provided, the default value is false. The field is optional.

Return value

Type	Description
CompletableFuture<List<Data>>	Future List<Data> associated with a given visitor.

Using parameters in getRemoteVisitorData()

The getRemoteVisitorData() method offers flexibility by allowing you to define various parameters when retrieving data on visitors. Whether you’re targeting based on goals, experiments, or variations, the same approach applies across all data types.

For example, let’s say you want to retrieve data on visitors who completed a goal “Order transaction”. You can specify parameters within the getRemoteVisitorData() method to refine your targeting. For instance, if you want to target only users who converted on the goal in their last five visits, you can set the previousVisitAmount parameter to 5 and conversions to true.

The flexibility shown in this example is not limited to goal data. You can use parameters within the getRemoteVisitorData() method to retrieve data on a variety of visitor behaviors.

Here is the list of available kameleoon.types.RemoteVisitorDataFilter options:

Name	Type	Description	Default
previousVisitAmount optional	int	Number of previous visits to retrieve data from. Number between 1 and 25	1
currentVisit optional	boolean	If true, current visit data will be retrieved	true
customData optional	boolean	If true, custom data will be retrieved.	true
pageViews optional	boolean	If true, page data will be retrieved.	false
geolocation optional	boolean	If true, geolocation data will be retrieved.	false
device optional	boolean	If true, device data will be retrieved.	false
browser optional	boolean	If true, browser data will be retrieved.	false
operatingSystem optional	boolean	If true, operating system data will be retrieved.	false
conversions optional	boolean	If true, conversion data will be retrieved.	false
experiments optional	boolean	If true, experiment data will be retrieved.	false
kcs optional	boolean	If true, Kameleoon Conversion Score (KCS) will be retrieved. Requires the AI Predictive Targeting add-on	false
visitorCode optional	boolean	If true, Kameleoon will retrieve the visitorCode from the most recent visit and use it for the current visit. This is necessary if you want to ensure that the visitor, identified by their visitorCode, always receives the same variation across visits for Cross-device experimentation.	true
personalization optional	boolean	If true, personalization data will be retrieved. This is required for the personalization condition.	false
cbs optional	boolean	If true, Contextual Bandit score data will be retrieved.	false

getVisitorWarehouseAudience()

This method retrieves all audience data associated with the visitor in your data warehouse using the specified visitorCode and warehouseKey. The warehouseKey is typically your internal user ID. The customDataIndex parameter corresponds to the Kameleoon custom data that Kameleoon uses to target your visitors. You can refer to the warehouse targeting documentation for additional details. The method passes the result to the returned future as a CustomData object, confirming that the data has been added to the visitor and is available for targeting purposes.

CompletableFuture<CustomData> warehouseAudienceDataCF =
  kameleoonClient.getVisitorWarehouseAudience(visitorCode, warehouseKeyValue, customDataIndex);

// If you need to specify warehouse key
CompletableFuture<CustomData> warehouseAudienceDataCF =
  kameleoonClient.getVisitorWarehouseAudience(visitorCode, customDataIndex);

try {
  CustomData warehouseAudienceData = warehouseAudienceDataCF.get(5_000, TimeUnit.MILLISECONDS);
  // Your custom code
} catch (CancellationException | InterruptedException | ExecutionException | TimeoutException e) {
  // Catch exception
}

Parameters

Name	Type	Description
visitorCode	String	The unique identifier of the visitor for whom you want to retrieve and add the data.
warehouseKey	String	The unique key to identify the warehouse data (usually, your internal user ID). This field is optional.
customDataIndex	int	An integer representing the index of the custom data you want to use to target your BigQuery Audiences.

Return value

Type	Description
CompletableFuture<CustomData>	Future CustomData instance confirming that the data has been added to the visitor.

Exceptions thrown

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid (it is either empty or longer than 255 characters).

setLegalConsent()

You must use this method to specify whether the visitor has given legal consent to use personal data. Setting the legalConsent parameter to false limits the types of data that you can include in tracking requests. This method helps you adhere to legal and regulatory requirements while responsibly managing visitor data. You can find more information on personal data in the consent management policy.

// if you do not need to set the visitor code in a cookie to respond
kameleoonClient.setLegalConsent(visitorCode, true);

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
kameleoonClient.setLegalConsent(visitorCode, true, httpServletResponse);

Parameters

Name	Type	Description
visitorCode	String	The user’s unique identifier. This field is required.
legalConsent	boolean	A boolean value representing the legal consent status. true indicates the visitor has given legal consent, false indicates the visitor has never provided, or has withdrawn, legal consent. This field is required.
response	HttpServletResponse	The HTTP servlet response where values in the cookies will be adjusted based on the legal consent status. The field is optional.

Exceptions thrown

Type	Description
KameleoonException.VisitorCodeInvalid	Exception indicating that the provided visitor code is invalid. It is either empty or longer than 255 characters.

Consent revocation behavior

When you call setLegalConsent() with legalConsent=false, the SDK does not delete the kameleoonVisitorCode cookie. Instead, it stops extending the cookie’s expiration date, allowing the cookie to persist until it naturally expires.

If your compliance requirements demand the immediate removal of the cookie file upon opt-out, you must delete it manually using your framework’s native cookie management methods. The SDK will not remove the file automatically.

Goals and third-party analytics

trackConversion()

• 📨 Sends Tracking Data to Kameleoon

Use this method to track a conversion for a specific goal and user. This method requires visitorCode and goalId. In addition, this method also accepts an optional revenue, negative and metadata arguments. The visitorCode is usually identical to the one that was used when triggering the experiment.

The trackConversion() method doesn’t return any value. This method is non-blocking as the server call is made asynchronously.

The parameter isUniqueIdentifier is deprecated. Please use UniqueIdentifier instead.

The isUniqueIdentifier can also be useful in other edge-case scenarios, such as when you can’t access the anonymous visitorCode that was originally assigned to the visitor, but you do have access to an internal ID that is connected to the anonymous visitor using session merging capabilities.

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
int goalId = 83023;

kameleoonClient.trackConversion(visitorCode, goalId);

// Add metadata
CustomData cd = new CustomData(1, "metadata");
kameleoonClient.trackConversion(visitorCode, goalId, cd);

Parameters

Name	Type	Description	Default
visitorCode required	String	Unique identifier of the visitor.
goalId required	int	ID of the goal.
revenue optional	float	Revenue of the conversion.	0
negative optional	boolean	Defines if the revenue is positive or negative.	false
metadata optional	CustomData...	Lets you set specific values for custom data which have been defined as metadata for the goal in the Kameleoon App. Example: [CustomData{id: 5, value: "Payment Type"}, CustomData{id: 6, value: "Delivery Method"}]. In this example, 5 and 6 are the indexes of the custom data (5 = “Payment Type”, 6 = “Delivery Method”).	new CustomData[0]
isUniqueIdentifier (deprecated)	boolean	An optional parameter for specifying if the visitorCode is a unique identifier.	false

metadata values are accessible through raw data exports and the results page.

If the metadata parameter is provided, Kameleoon will use these specified values for the current conversion instead of what was previously collected using the addData() method. If the parameter is omitted, Kameleoon will use the last tracked values for those CustomData prior to the conversion and within the same visit.

Kameleoon will only consider the metadata values that are explicitly passed as parameters to the trackConversion() method.

In the example below, Kameleoon will associate the conversion only with the custom data value explicitly provided as a parameter (here: index 5 with the value ‘Amex Credit Card’).

kameleoonClient.addData(visitorCode, new CustomData(5, "Credit Card"), new CustomData(9, "Express Delivery"));
kameleoonClient.trackConversion(visitorCode, 1000, new CustomData(5, "Amex Credit Card"));

Exceptions

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.

getEngineTrackingCode()

Kameleoon integrates with several analytics solutions, including Mixpanel, Google Analytics 4, and Segment. To track server-side experiments correctly, call the getEngineTrackingCode() method after the visitor triggers an experiment. The SDK returns JavaScript queue commands for the experiments that the visitor triggered during the previous five seconds. When you insert this code into the page, Engine.js processes the commands and sends the exposure events through the active analytics integration.

Refer to hybrid experimentation for more information on implementing this method.

String engineTrackingCode = kameleoonClient.getEngineTrackingCode(visitorCode);

• To use this feature, implement both the Java SDK and Kameleoon Engine.js. Because Engine.js is used only for tracking in this flow, you can install the asynchronous tag before the closing </body> tag.
• If you only want to track experiments in Kameleoon and do not need to send exposure events to third-party analytics tools, use the JavaScript / TypeScript SDK. This option works well for serverless edge compute platforms. The JavaScript / TypeScript SDK automatically tracks variations when you call getVisitorCode, as long as you add the corresponding experiment assignments to window.kameleoonQueue.
• You can insert the returned tracking code directly into an HTML <script> tag.

<html lang="en">
  <body>
    <script>
      const engineTrackingCode = `
        window.kameleoonQueue = window.kameleoonQueue || [];
        window.kameleoonQueue.push(['Experiments.assignVariation', 123456, 7890, true]);
        window.kameleoonQueue.push(['Experiments.trigger', 123456, true]);
        window.kameleoonQueue.push(['Experiments.assignVariation', 234567, 8901, true]);
        window.kameleoonQueue.push(['Experiments.trigger', 234567, true]);
      `;
      const script = document.createElement('script');

      script.textContent = engineTrackingCode;
      document.body.appendChild(script);
    </script>

  </body>
</html>

In this example, 123456 and 234567 are experiment IDs, and 7890 and 8901 are variation IDs. In your implementation, the SDK generates these values in the returned tracking code.

Parameters

Name	Type	Description
visitorCode required	String	Unique identifier of the visitor.

Return value

Type	Description
String	JavaScript code to insert into the page.

Events

setEventHandler()

Use this method to register a handler for SDK events. The SDK calls the handler when the selected event occurs. Registering a new handler for the same event type replaces the previous handler.

Passing null as the handler removes the current handler for the selected event type.

DATAFILE_UPDATE

import com.kameleoon.events.DataFileUpdateEvent;
import com.kameleoon.events.EventType;

kameleoonClient.setEventHandler(EventType.DATAFILE_UPDATE, event -> {
  DataFileUpdateEvent.Source source = event.getSource(); // POLLING or STREAMING
  long dateModified = event.getDateModified(); // Data file modification date in milliseconds.

  // React to the data file update.
});

// Clear the handler.
kameleoonClient.setEventHandler(EventType.DATAFILE_UPDATE, null);

DataFileUpdateEvent contains information about an SDK data file update.

Name	Type	Description
source	DataFileUpdateEvent.Source	The update source. POLLING indicates a scheduled data file refresh, and STREAMING indicates a real-time update received through streaming mode.
dateModified	long	The modification date of the updated data file, in milliseconds.

HTTP_REQUEST

import com.kameleoon.events.EventType;
import com.kameleoon.events.HttpRequestFailure;
import com.kameleoon.events.HttpRequestHandler;
import com.kameleoon.events.HttpRequestHandler.RequestType;

kameleoonClient.setEventHandler(EventType.HTTP_REQUEST, new HttpRequestHandler() {
  @Override
  public void onRequestSucceeded(RequestType requestType, int httpStatus, long durationMillis) {
    // The SDK request completed successfully.
  }

  @Override
  public void onRequestFailed(RequestType requestType, HttpRequestFailure failure, long durationMillis) {
    HttpRequestFailure.Reason reason = failure.getReason();
    Integer httpStatus = failure.getHttpStatus();
    Throwable cause = failure.getCause();

    // The SDK request failed.
  }
});

// Clear the handler.
kameleoonClient.setEventHandler(EventType.HTTP_REQUEST, null);

HttpRequestHandler lets you react to completed SDK HTTP requests. The SDK calls onRequestSucceeded() for successful responses and onRequestFailed() for failed responses, exceptions, or cancelled requests.

Method	Description
onRequestSucceeded()	Called when an SDK HTTP request completes successfully.
onRequestFailed()	Called when an SDK HTTP request fails because of an HTTP status, exception, or cancellation.

Callback parameters and failure details

Callback parameters

Name	Type	Description
requestType	HttpRequestHandler.RequestType	The SDK request type. Possible values are DATAFILE, TRACKING, REMOTE_VISITOR_DATA, REMOTE_DATA, and ACCESS_TOKEN.
httpStatus	int	The HTTP status code returned by the request. Passed only to onRequestSucceeded().
failure	HttpRequestFailure	Details about why the request failed. Passed only to onRequestFailed().
durationMillis	long	The request duration in milliseconds.

HttpRequestFailure

HttpRequestFailure contains details about a failed SDK HTTP request.

Name	Type	Description
reason	HttpRequestFailure.Reason	The failure reason. Possible values are HTTP_STATUS, EXCEPTION, and CANCELLED.
httpStatus	Integer	The HTTP status code for failures caused by an unsuccessful HTTP response. This value is null for exception and cancellation failures.
cause	Throwable	The exception that caused the request to fail. This value is null when the request failed because of an HTTP status or cancellation.

Parameters

Name	Type	Description
eventType required	EventType<T>	The SDK event type to handle. Use EventType.DATAFILE_UPDATE to react to SDK data file updates, or EventType.HTTP_REQUEST to react to completed SDK HTTP requests.
handler required	T extends EventHandler	The handler to register for the selected event type. Use a DataFileUpdateHandler for EventType.DATAFILE_UPDATE, or an HttpRequestHandler for EventType.HTTP_REQUEST. Pass null to remove the current handler.

Data types

This section lists the data types supported by Kameleoon in com.kameleoon.Data. We provide several standard data types as well as the CustomData type that allows you to define custom data types.

Browser

The Browser data set stored here can be used to filter experiment and personalization reports by any value associated with it.

Name	Type	Description
type required	Browser.Type	List of browsers: CHROME, INTERNET_EXPLORER, FIREFOX, SAFARI, OPERA, OTHER.
version optional	Float	Version of the browser, floating point number represents major and minor version of the browser

kameleoonClient.addData(visitorCode, Browser.chrome());
kameleoonClient.addData(visitorCode, Browser.safari());

kameleoonClient.addData(visitorCode, new Browser(Browser.Type.CHROME, 10.0));

Conversion

The Conversion data set stored here can be used to filter experiment and personalization reports by any goal associated with it.

• Each visitor can have multiple Conversion objects.
• You can find the goalId in the Kameleoon app.

Name	Type	Description	Default
goalId required	int	ID of the goal.
revenue optional	float	Revenue of the conversion	0
negative optional	boolean	Defines if the revenue is positive or negative.	false
metadata optional	CustomData...	Metadata of the conversion.	new CustomData[0]

kameleoonClient.addData(visitorCode, new Conversion(32, 10f));

kameleoonClient.addData(visitorCode, new Conversion(33, null, true));

kameleoonClient.addData(
    visitorCode,
    new Conversion(34, 5f, new CustomData(3, "metadata1", "md2"), new CustomData(5, "md3"))
);

Cookie

Cookie contains information about the cookie stored on the visitor’s device.

Name	Type	Description
cookies	Map<String, String>	A string object map consisting of cookie keys and values. This field is required.

Each visitor can only have one Cookie. Adding a second Cookie overwrites the first one.

Cookie cookie = new Cookie (new HashMap<String, String>() {{
    put("my_key1", "my_value1");
    put("my_key2", "my_value1");
}});
kameleoonClient.addData(visitorCode, cookie);

Geolocation

Geolocation contains the visitor’s geolocation details.

Name	Type	Description
country required	String	The country of the visitor.
region optional	String	The region of the visitor.
city optional	String	The city of the visitor.
postalCode optional	String	The postal code of the visitor.
latitude optional	float	The latitude coordinate representing the location of the visitor. Coordinate number represents decimal degrees.
longitude optional	float	The longitude coordinate representing the location of the visitor. Coordinate number represents decimal degrees.

• Each visitor can have only one Geolocation. Adding a second Geolocation overwrites the first one.

kameleoonClient.addData(visitorCode, new Geolocation("France", "Île-de-France", "Paris"));

CustomData

CustomData enables the association of any type of data with each visitor, making it an effective tool for targeting conditions in segments. Additionally, it can be used as a filter or breakdown in experiment reports. For more information about custom data, please refer to this article.

Define custom data types in the Kameleoon app or the Data API and use them from the SDK.

Name	Type	Description	Default
index/name required	int/String	Index or Name of the custom data. Either index or name must be provided to identify the data..
values required	String.../List<String>	Values of the custom data to be stored.
overwrite optional	boolean	Flag to explicitly control how the values are stored and how they appear in reports. See more	true

• Each visitor is allowed only one CustomData for each unique index(name). Adding another CustomData with the same index(name) will replace the existing one.

• The custom data ‘index’ can be found in the Custom Data dashboard under the “INDEX” column.

• To prevent the SDK from sending data with the selected index to Kameleoon servers for privacy reasons, enable the option: Use this data only locally for targeting purposes when creating custom data.

• Adding a CustomData instance created with a name when the SDK instance is not initialized or the name is not registered, will result in the data being ignored.

kameleoonClient.addData(visitorCode, new CustomData(1, "value"));

// With several values
kameleoonClient.addData(visitorCode, new CustomData(1, "value1", "value2"));

// To set the 'overwrite' flag to false
kameleoonClient.addData(visitorCode, new CustomData(1, false, "value"));

// To use a name instead of the index
kameleoonClient.addData(visitorCode, new CustomData("my-custom-data", "value"));

Device

Name	Type	Description
device	Device	List of devices: PHONE, TABLET, DESKTOP. This field is required.

kameleoonClient.addData(visitorCode, Device.desktop());

PageView

Store page view events.

Name	Type	Description
url	String	URL of the page viewed. This field is required.
title	String	Title of the page viewed. This field is required.
referrers	List<Integer>	Referrers of viewed pages. This field is optional.

The referrer’s index (ID) is available in the Kameleoon app in the acquisition channel configuration page. Be careful: this index starts at 0, so the first acquisition channel you create for the specified site would have the ID 0, not 1.

kameleoonClient.addData(
  visitorCode,
  new PageView("https://url.com", "title", Array.asList(3))
);

UserAgent

Server-side experiments are more likely to be affected by bot traffic than client-side experiments. Kameleoon uses the IAB/ABC International Spiders and Bots List to tackle this issue and recognize known bots and spiders. Kameleoon also uses the UserAgent field to filter out bots and other unwanted traffic that might distort your conversion metrics. For more details, see our help article on bot filtering.

If you use internal bots, we suggest that you pass the value curl/8.0 of the userAgent to exclude them from our analytics.

Name	Type	Description
value	String	The User-Agent value that will be sent with tracking requests. This field is required.

kameleoonClient.addData(visitorCode, new UserAgent("Your User Agent"));

UniqueIdentifier

If you don’t add UniqueIdentifier for a visitor, visitorCode is used as the unique visitor identifier, which is useful for Cross-device experimentation. When you add UniqueIdentifier for a visitor, the SDK links the flushed data with the visitor associated with the specified identifier.

The isUniqueIdentifier can be helpful in unique situations; for example, if you cannot access the anonymous visitorCode given to a visitor, but you can use an internal ID linked to that visitor through session merging.

Name	Type	Description
value	boolean	Parameter specifying if the visitorCode is a unique identifier. This field is required.

kameleoonClient.addData(visitorCode, new UniqueIdentifier(true));

OperatingSystem

OperatingSystem contains information about the operating system on the visitor’s device.

Name	Type	Description
type	OperatingSystem.Type	List of operating systems: WINDOWS_PHONE, WINDOWS, ANDROID, LINUX, MAC, and IOS. This field is required.

Each visitor can only have one OperatingSystem. Adding a second OperatingSystem overwrites the first one.

kameleoonClient.addData(visitorCode, new OperatingSystem(OperatingSystem.Type.WINDOWS));

kameleoonClient.addData(visitorCode, OperatingSystem.mac());

ApplicationVersion

ApplicationVersion represents the semantic version number of your application.

A visitor can have only one ApplicationVersion. Adding a second instance will overwrite the first one.

Name	Type	Description
version optional	String	The mobile application version. This field must follow semantic versioning. Accepted formats are major, major.minor, or major.minor.patch.

kameleoonClient.addData(visitorCode, new ApplicationVersion("10")); // major

kameleoonClient.addData(visitorCode, new ApplicationVersion("10.20")); // major.minor

kameleoonClient.addData(visitorCode, new ApplicationVersion("10.20.30")); // major.minor.patch

Returned Types

DataFile

The DataFile contains the SDK configuration details.

It can be extended with additional information if required by clients. If you need more details, please contact your Customer Success Manager.

Name	Type	Description
featureFlags	Map<String, FeatureFlag>	A map of FeatureFlag objects, keyed by feature flag keys.
dateModified	long	The timestamp (in milliseconds) indicating when the DataFile was last modified.

// Retrieves the map of feature flags from the DataFile.
// The map is keyed by feature flag identifiers, with each value being a FeatureFlag object.
Map<String, FeatureFlag> featureFlags = dataFile.getFeatureFlags();

// Retrieves the last modification timestamp of the DataFile.
// The value is a long representing milliseconds since the Unix epoch.
long dateModified = dataFile.getDateModified();

FeatureFlag

The FeatureFlag represents a set of properties that define a feature flag itself — for example, its Variations, Rules, environment status, and other related details.

It can be extended with additional information if required by clients. If you need more details, please contact your Customer Success Manager.

Name	Type	Description
environmentEnabled	boolean	Indicating whether the feature flag is enabled in the current environment.
defaultVariationKey	String	The key of the default variation associated with the feature flag.
variations	Map<String, Variation>	A map of Variation objects, keyed by variation keys.
rules	List<Rule>	A list of Rule objects

// Check whether the feature flag is enabled in the current environment
boolean isEnvironmentEnabled = featureFlag.isEnvironmentEnabled();

// Retrieve the key of the default variation
String defaultVariationKey = featureFlag.getDefaultVariationKey();

// Retrieve the default variation object
Variation defaultVariation = featureFlag.getDefaultVariation();

// Retrieve all variations of the feature flag as a map (key = variation key, value = Variation object)
Map<String, Variation> variations = featureFlag.getVariations();

// Retrieve all targeting rules associated with the feature flag
List<Rule> rules = featureFlag.getRules();

Rule

The Rule represents a set of properties that define a rule itself — for example, its Variations.

It can be extended with additional information if required by clients. If you need more details, please contact your Customer Success Manager.

Name	Type	Description
variations	Map<String, Variation>	A map of Variation objects, keyed by variation keys.

// Retrieve all variations of the rule as a map (key = variation key, value = Variation object)
Map<String, Variation> variations = rule.getVariations();

Variation

Variation contains information about the visitor’s assigned variation (or the default variation, if no specific assignment exists).

Name	Type	Description
name	String	The name of the variation.
key	String	The unique key identifying the variation.
id	Integer	The ID of the assigned variation (or null if it’s the default variation).
experimentId	Integer	The ID of the experiment associated with the variation (or null if default).
variables	Map<String, Variable>	A map containing the variables of the assigned variation, keyed by variable names. This could be an empty collection if no variables are associated.

• The Variation object provides details about the assigned variation and its associated experiment, while the Variable object contains specific details about each variable within a variation.
• Ensure that your code handles the case where id or experimentId may be null, indicating a default variation.
• The variables map might be empty if no variables are associated with the variation.

// Retrieving the variation name
String variationName = variation.getName();

// Retrieving the variation key
String variationKey = variation.getKey();

// Retrieving the variation id
Integer variationId = variation.getId();

// Retrieving the experiment id
Integer experimentId = variation.getExperimentId();

// Retrieving the variables map
Map<String, Variable> variables = variation.getVariables();

Variable

Variable contains information about a variable associated with the assigned variation.

Name	Type	Description
key	String	The unique key identifying the variable.
type	String	The type of the variable. Possible values: BOOLEAN, NUMBER, STRING, JSON, JS, CSS.
value	Object	The value of the variable, which can be of the following types: Boolean, Integer, Long, Double, String, JsonObject, JsonArray.

// Retrieving the variables map
Map<String, Variable> variables = variation.getVariables();

// Variable type can be retrieved for further processing
String type = variables.get("isDiscount").getType();

// Retrieving the variable value by key
Boolean isDiscount = (Boolean) variables.get("isDiscount").getValue();

// Variable value can be of different types
String title = (String) variables.get("title").getValue();

Deprecated methods

These methods are deprecated and will be removed in SDK version 5.0.0.

getFeatureVariationKey()

• 📨 Sends Tracking Data to Kameleoon

Use getVariation() instead.

Call this method to get the feature variation key for a specified user and feature. This method takes a visitorCode and featureKey as mandatory arguments to get the variation key for the user and feature.

If the user has never been associated with this feature flag, the SDK returns a randomly-assigned variation key (according to the feature flag rules). If a user with the specified visitorCode is already registered with this feature flag, the SDK detects the previous variation key value. If the user doesn’t match any of the rules, the default value is returned, which you can customize in the Kameleoon app.

Make sure you catch and handle potential exceptions.

If you specify a visitorCode, the flush() method uses it as the unique visitor identifier, which is useful for Cross-device experimentation. When you specify a visitorCode and set the isUniqueIdentifier parameter to true, the SDK links the flushed data with the visitor associated with the specified identifier.

The parameter isUniqueIdentifier is deprecated. Please use UniqueIdentifier instead.

The isUniqueIdentifier can be helpful in unique situations; for example, if you cannot access the anonymous visitorCode given to a visitor, but you can use an internal ID linked to that visitor through session merging.

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
String featureKey = "new_checkout";
String variationKey = ""

try {
  variationKey = kameleoonClient.GetFeatureVariationKey(visitorCode, featureKey);
} catch (KameleoonException.FeatureNotFound e) {
  // The error has occurred; the feature flag isn't found in the current configuration
} catch (KameleoonException.FeatureEnvironmentDisabled e) {
  // The feature flag is disabled for the environment
} catch (KameleoonException.VisitorCodeInvalid e) {
  // The visitor code you passed to the method is invalid and can't be accepted by SDK.
}

switch (variationKey) {
  case 'on':
    // Main variation key is selected for visitorCode
    break;
  case 'alternative_variation':
    // Alternative variation key
    break;
  default:
    // Default variation key
    break;
}

Parameters

Name	Type	Description
visitorCode	String	Unique identifier of the user. This field is required.
featureKey	String	Key of the feature you want to expose to a user. This field is required.
isUniqueIdentifier (Deprecated)	boolean	An optional parameter for specifying if the visitorCode is a unique identifier. If not provided, the default value is false. The field is optional.

Return value

Type	Description
String	Variation key of the feature flag that is registered for the specified visitorCode.

Exceptions thrown

Type	Description
KameleoonException.FeatureNotFound	Exception indicating that the requested feature key wasn’t found in the SDK’s internal configuration. This exception usually means that the feature flag is not activated in the Kameleoon app (but code implementing the feature is already deployed on your application).
KameleoonException.FeatureEnvironmentDisabled	Exception indicating that feature flag is disabled for the visitor’s current environment (for example, production, staging, or development).
KameleoonException.VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is empty or longer than 255 characters.

getActiveFeatures()

Use getVariations() instead.

This method takes a single visitorCode parameter. Result contains only active features for a given visitor.

try {
    Map<String, Variation> activeFeatures = kameleoonClient.getActiveFeatures(visitorCode);
} catch (VisitorCodeInvalid e) {
    //  Handle exception
}

Parameters

Name	Type	Description
visitorCode	String	User’s unique identifier. This field is required.

Return value

Type	Description
Map<String, Variation>	Map that contains the assigned variations of the active features using the corresponding active features’ keys.

Exceptions thrown

Type	Description
VisitorCodeInvalid	Exception indicating that the provided visitor code is not valid. It is either empty or longer than 255 characters.

getActiveFeatureListForVisitorCode()

• Use getVariations() instead.
• This method was previously called obtainFeatureListForVisitorCode, which was removed in SDK version 4.0.0.

This method takes a single visitorCode parameter. Return only the active feature flags for the specified visitor.

List<String> listActiveFeatureFlags = kameleoonClient.getActiveFeatureListForVisitorCode(visitorCode);

Parameters

Name	Type	Description
visitorCode	String	User’s unique identifier. This field is required.

Return value

Type	Description
List<String>	List of active feature flag keys available for specific visitorCode

getFeatureVariable()

• 📨 Sends Tracking Data to Kameleoon

Use getVariation() instead.

Call this method to get a user’s associated feature variation value. This method takes a visitorCode, featureKey and variableKey as required arguments to get the variation key’s variable for the specified user.

If a user has never been associated with this feature flag, the SDK returns a randomly assigned variable value of the variation key according to the feature flag rules. If a user with the specified visitorCode is already registered with this feature flag, the SDK returns the variable value for previously associated variation. If the user does not match any of the rules, the default variable is returned.

Make sure you catch and handle potential exceptions.

If you specify a visitorCode, the getFeatureVariable() method uses the code as the unique visitor identifier, which is useful for cross-device experimentation. When you specify a visitorCode and set the isUniqueIdentifier parameter to true, the SDK links the flushed data with the visitor associated with the specified identifier.

The parameter isUniqueIdentifier is deprecated. Please use UniqueIdentifier instead.

The isUniqueIdentifier can be helpful in unique situations; for example, if you cannot access the anonymous visitorCode given to a visitor, but you can use an internal ID linked to that visitor through session merging.

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
String featureKey = "feature_key";
String variableKey = "var"

try {
  var variableValue = kameleoonClient.getFeatureVariable(visitorCode, featureKey, variableKey);
  // Your custom code, depending on variableValue.
} catch (KameleoonException.FeatureNotFound e) {
  // The error has occurred; the feature flag isn't found in current configuration
} catch (KameleoonException.FeatureEnvironmentDisabled e) {
  // The feature flag is disabled for the environment.
} catch (KameleoonException.FeatureVariableNotFound e) {
  // Requested variable not defined on Kameleoon's side
} catch (KameleoonException.VisitorCodeInvalid e) {
  // The visitor code passed to the method is invalid and can't be accepted by SDK.
}

Parameters

Name	Type	Description
visitorCode	String	Unique identifier of the user. This field is required.
featureKey	String	Key of the feature you want to expose to a user. This field is required.
variableKey	String	Name of the variable you want to get a value for. This field is required.
isUniqueIdentifier (Deprecated)	boolean	An optional parameter for specifying if the visitorCode is a unique identifier. If not provided, the default value is false. The field is optional.

Return value

Type	Description
object	Value of variable of variation that is registered for the specified visitorCode for this feature flag. Possible types: bool, int, double, string, JObject, JArray

Exceptions thrown

Type	Description
KameleoonException.FeatureNotFound	Exception indicating that the requested feature key wasn’t found in the internal SDK configuration. This usually means that the feature flag has not yet been activated in the Kameleoon app (but code implementing the feature is already deployed in your application).
KameleoonException.FeatureEnvironmentDisabled	Exception indicating that feature flag is disabled for the visitor’s current environment (for example, production, staging, or development).
KameleoonException.FeatureVariableNotFound	Exception indicating that the requested variable wasn’t found. Check that the variable’s key in the Kameleoon app matches your code.
KameleoonException.VisitorCodeInvalid	Exception indicating that the specified visitor code is not valid. (It is either empty or longer than 255 characters).

getFeatureVariables()

• 📨 Sends Tracking Data to Kameleoon

Use getVariation() instead.

This method retrieves a map containing variable keys and their values assigned according the variation that the visitor is assigned in the specified feature flag. Feature variables can be modified in the Kameleoon app.

If a user has never been associated with this feature flag, the SDK returns a randomly assigned set of variable values in the variation according to the feature flag rules. If a user with the specified visitorCode is already registered with this feature flag, the SDK returns the variable values for the variation used previously. If the user does not match any of the rules, the default variables are returned.

Make sure you catch and handle potential exceptions.

String visitorCode = kameleoonClient.getVisitorCode(httpServletRequest, httpServletResponse);
String featureKey = "feature_key";
String variableKey = "var"

try {
  var variableValue = kameleoonClient.getFeatureVariables(visitorCode, featureKey);
  // Your custom code, depending on variable values.
} catch (KameleoonException.FeatureNotFound e) {
  // The error has occurred; the feature flag isn't found in current configuration.
} catch (KameleoonException.FeatureEnvironmentDisabled e) {
  // The feature flag is disabled for the environment.
} catch (KameleoonException.FeatureVariableNotFound e) {
  // Requested variable not defined on Kameleoon's side
} catch (KameleoonException.VisitorCodeInvalid e) {
  // The visitor code passed to the method is invalid and can't be accepted by SDK.
}

Parameters

Name	Type	Description
featureKey	String	Key of the feature you want to obtain. This field is required.
variationKey	String	Key of the variation you want to obtain. This field is required.

Return value

Type	Description
Map<String,Object>	Data associated with this feature flag. The values can be Boolean, Integer, Double, String, JsonObject, or JsonArray (the type is defined in the Kameleoon app).

Exceptions thrown

Type	Description
KameleoonException.FeatureNotFound	Exception indicating that the requested feature key wasn’t found in the internal SDK configuration. This exception usually means that the feature flag has not been activated in the Kameleoon app (but code implementing the feature is already deployed in your application).
KameleoonException.FeatureEnvironmentDisabled	Exception indicating that feature flag is disabled for the visitor’s current environment (for example, production, staging, or development).
KameleoonException.FeatureVariationNotFound	Exception indicating that the requested variation key wasn’t found in the internal configuration of the SDK. This usually means that the variation’s corresponding experiment is not activated in the Kameleoon app.
KameleoonException.VisitorCodeInvalid	Exception indicating that the specified visitor code is not valid. (It is either empty or longer than 255 characters).

getFeatureVariationVariables()

• Use getVariation() instead.
• This method was previously called getFeatureAllVariables, which was removed in SDK version 4.0.0.

Call this method to retrieve all feature variables for a feature. You can modify feature variables in the Kameleoon app.

This method takes two input parameters: featureKey and variationKey. It returns the data with the Map<String, Object> type as defined in the Kameleoon app. It throws an exception (KameleoonException.FeatureNotFound) if the feature you request isn’t found in the SDK’s internal configuration.

String featureKey = "featureKey";
String variationKey = "variationKey";

try {
  Map<String, Object> allVariables = kameleoonClient.getFeatureVariationVariables(featureKey, variationKey);
} catch (KameleoonException.FeatureNotFound e) {
  // The feature is not activated in the Kameleoon app.
} catch (KameleoonException.FeatureEnvironmentDisabled e) {
  // The feature flag is disabled for the environment.
} catch (KameleoonException.FeatureVariationNotFound e) {
  // The variation is not activated in the Kameleoon app (most likely, the associated experiment is not active)
} catch (Exception e) {
  // This is a generic Exception handler which will handle all exceptions.
  System.out.println("Exception occurred");
}

Parameters

Name	Type	Description
featureKey	String	Key of the feature you want to obtain. This field is required.
variationKey	String	Key of the variation you want to obtain. This field is required.

Return value

Type	Description
Map<String,Object>	Data associated with this feature flag. The values can be Boolean, Integer, Double, String, JsonObject, JsonArray (depending on the type defined in the Kameleoon app).

Exceptions thrown

Type	Description
KameleoonException.FeatureNotFound	Exception indicating that the requested feature wasn’t found in the internal configuration of the SDK. This exception usually means that the feature flag is not activated in the Kameleoon app.
KameleoonException.FeatureEnvironmentDisabled	Exception indicating that feature flag is disabled for the visitor’s current environment (for example, production, staging, or development).
KameleoonException.FeatureVariationNotFound	Exception indicating that the requested variation key wasn’t found in the internal configuration of the SDK. This usually means that the variation’s corresponding experiment is not activated in the Kameleoon app.

updateConfigurationHandler()

The updateConfigurationHandler() method allows you to handle the event when configuration has updated data. It takes one input parameter, handler. The handler that will be called when the configuration is updated using a real-time configuration event.

kameleoonClient.updateConfigurationHandler(() -> {
  // Configuration was updated
});

Parameters

Name	Type	Description
handler	KameleoonUpdateConfigurationHandler	The handler that will be called when the configuration is updated using a real-time configuration event.