> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kameleoon.com/llms.txt
> Use this file to discover all available pages before exploring further.
# 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](#developer-guide)
**Changelog**: Latest version of the Java SDK: 4.22.0 [Changelog](https://github.com/Kameleoon/client-java/blob/master/CHANGELOG.md).
**SDK methods**: For the full reference documentation of the Java SDK, see the [reference](#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](https://github.com/Kameleoon/java-examples)
#### 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](https://search.maven.org/artifact/com.kameleoon/kameleoon-client-java) page for additional examples.
```java title="pom.xml" theme={null}
com.kameleoon
kameleoon-client-java
4.16.0
```
```java title="pom.xml" theme={null}
com.kameleoon
kameleoon-client-java-jakarta
4.16.0
```
#### Additional configuration
Create a `.properties` configuration file to provide credentials and customize SDK behavior. You can also [download our sample configuration](/assets/developer-docs/sdks/web-sdks/client-configs/client-java.properties) 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](/user-manual/account-and-team-management/users-and-teams/api-credentials) documentation. | |
| `clientSecret` / `client_secret` required | Required for authentication to the Kameleoon service. To find your `client_secret`, see the [API credentials](/user-manual/account-and-team-management/users-and-teams/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](/developer-docs/feature-experimentation/technical-reference/technical-considerations/#streaming-premium-option) 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](/user-manual/experimentation/feature-experimentation/configure-your-feature-flags/manage-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:
```java theme={null}
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("") // mandatory
.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](#create) 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()`](#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](/developer-docs/feature-experimentation/get-started/hybrid-experimentation), 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()`](#getvariation) or [`isFeatureActive()`](#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`](#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`](#additional-configuration). 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](/developer-docs/feature-experimentation/technical-reference/faq-global#when-does-the-sdk-send-a-tracking-request-for-analytics)
##### 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()`](#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()`](#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](/developer-docs/feature-experimentation/targeting-and-segmentation/native-segmentation).
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](/user-manual/experiment-analytics/analyze-results/results-page-settings#breakdown-audience).
If you need to track additional data points beyond what's automatically collected, you can use Kameleoon's [Custom Data feature](#customdata). Custom Data allows you to capture and analyze specific information relevant to your experiments. Don't forget to call the [`flush()`](#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`](#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()`](#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`](#additional-configuration)). If you prefer to send the request immediately, use the [`flush()`](#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](/developer-docs/feature-experimentation/get-started/hybrid-experimentation/). Then, use the [`getEngineTrackingCode()`](#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:
```java theme={null}
kameleoonClient.addData(visitorCode, new CustomData(index, "newVisitorCode"));
```
* **Providing the custom key:** You provide your custom identifier to the Kameleoon SDK using the [`addData()`](#adddata) method. In this method, you will pass your chosen custom bucketing key as a [`CustomData`](#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](/user-manual/experimentation/feature-experimentation/create-and-manage-flags/create-a-feature-flag#Advanced_Flag_Settings).
* **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](/developer-docs/feature-experimentation/targeting-and-segmentation/native-segmentation).
You can also use your own [external data to target users](/developer-docs/apis/data-api-rest/tutorials/storing-and-retrieving-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](/developer-docs/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()`](#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.
```java title="Device A" theme={null}
// 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);
```
```java title="Device B" theme={null}
// 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](/developer-docs/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`](#customdata) to provide a unique identifier for the visitor. For more information, see the [dedicated documentation](/developer-docs/cross-device-experimentation/#activating-cross-device-history-reconciliation).
After cross-device reconciliation is enabled, calling [`getRemoteVisitorData()`](#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](/developer-docs/cross-device-experimentation#critical-points-and-practical-insights).
Follow the [activating cross-device history reconciliation](#cross-device-experimentation) 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()`](#trackconversion) or [`flush()`](#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](/developer-docs/cross-device-experimentation) to retrieve the identifier with the [`getRemoteVisitorData()`](#getremotevisitordata) method on each device.
Here's an example of how to use custom data for session merging.
```java theme={null}
// 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()`](#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.
```java theme={null}
// 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.
```java theme={null}
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`.
```java theme={null}
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("") // mandatory
.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](/user-manual/faq#how-do-i-find-my-sitecode) 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.
```java theme={null}
// 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` | 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. |
### 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 `featureFlag`value.
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](/developer-docs/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`](#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.
```java theme={null}
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`](#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.
```java theme={null}
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`](#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`](#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.
```java theme={null}
try {
Map variations = kameleoonClient.getVariations(visitorCode);
// only active variations
Map variations = kameleoonClient.getVariations(visitorCode, true);
// disable tracking
Map 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` | Map that contains the assigned [`Variation`](#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`](#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](#getvisitorcode)** variations:
* **Forced variations**: Are specific to an individual experiment.
* **Simulated variations**: Affect the overall **feature flag** result.
```java theme={null}
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.
```java theme={null}
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.
```java theme={null}
List allFeatureFlagKey = kameleoonClient.getFeatureList();
```
##### Return value
| Type | Description |
| -------------- | ------------------------- |
| `List` | List of feature flag keys |
#### getDataFile()
To evaluate all feature flags, use [`getVariations()`](#getvariations). This method is more efficient than calling `DataFile` and iterating through flags with [`getVariation()`](#getvariation).
Returns the current SDK configuration as a [`DataFile`](#datafile) object.
```java theme={null}
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`](#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](/developer-docs/feature-experimentation/get-started/hybrid-experimentation/).
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`](#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](/developer-docs/feature-experimentation/get-started/hybrid-experimentation#linking-feature-experiments-with-front-end-tracking-code), the cookie is created automatically when simulating a variant's display using the [Simulation Panel](/user-manual/experimentation/feature-experimentation/using-the-rollout-planner/validation-and-rollback/using-simulation-mode).
* **Manually:** Set the `kameleoonSimulationFFData` cookie manually.
It’s important to distinguish **simulated** variations from **[forced](#setforcedvariation)** 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`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent).
```java theme={null}
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](#data-types) 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()`](#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()`](#trackconversion) method also sends out any previously associated data, just like the `flush()`. The same holds true for [`getVariation()`](#getvariation) and [`getVariations()`](#getvariations) methods if an experimentation rule is triggered.
Each visitor can only have one instance of associated data for most data types. However, [`CustomData`](#customdata) is an exception. Visitors can have one instance of associated `CustomData` per index.
```java theme={null}
// 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](/developer-docs/feature-experimentation/technical-reference/faq-global#when-does-the-sdk-send-a-tracking-request-for-analytics). `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](/developer-docs/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`](#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.
```java theme={null}
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`](#additional-configuration). 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.
```java theme={null}
CompletableFuture 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` | 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](/developer-docs/feature-experimentation/targeting-and-segmentation/native-segmentation) 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](/developer-docs/sdks/web-sdks/nodejs-sdk#synchronizing-custom-data-across-devices).
The parameter `isUniqueIdentifier` is deprecated. Please use [`UniqueIdentifier`](#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.
```java theme={null}
String visitorCode = "visitorCode";
// Visitor data will be fetched and automatically added for `visitorCode`
CompletableFuture> visitorData = kameleoonClient.getRemoteVisitorData(visitorCode);
// If you only want to fetch data and add it yourself manually, set addData == `false`
CompletableFuture> 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> visitorData = kameleoonClient.getRemoteVisitorData(visitorCode, filter, true, false);
try {
List 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>` | Future `List` 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](/user-manual/assets/segments/target-users-based-on-likelihood-to-convert) | `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](/developer-docs/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](/user-manual/integrations/data-warehouses/bigquery/use-bigquery-as-a-source-audience-targeting) 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.
```java theme={null}
CompletableFuture warehouseAudienceDataCF =
kameleoonClient.getVisitorWarehouseAudience(visitorCode, warehouseKeyValue, customDataIndex);
// If you need to specify warehouse key
CompletableFuture 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` | 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](/user-manual/project-management/consent-management-policy).
```java theme={null}
// 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](/user-manual/assets/goals/create-a-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`](#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.
```java theme={null}
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](/user-manual/experiment-analytics/analyze-results/results-page-actions#Export) and [the results page](/user-manual/experiment-analytics/analyze-results/goal-metadata).
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()`](#adddata) method. If the parameter is omitted, Kameleoon will use the last tracked values for those [`CustomData`](#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').
```java theme={null}
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](/developer-docs/feature-experimentation/get-started/hybrid-experimentation) for more information on implementing this method.
```java theme={null}
String engineTrackingCode = kameleoonClient.getEngineTrackingCode(visitorCode);
```
* To use this feature, implement both the Java SDK and Kameleoon [Engine.js](/developer-docs/web-experimentation/implementation-and-deployment/standard-implementation). Because Engine.js is used only for tracking in this flow, you can install the asynchronous tag before the closing `` 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](/developer-docs/sdks/web-sdks/js-sdk). This option works well for [serverless edge compute platforms](/developer-docs/feature-experimentation/implementation-and-deployment/serverless-edge-compute-starter-kits). The JavaScript / TypeScript SDK automatically tracks variations when you call [`getVisitorCode`](/developer-docs/sdks/web-sdks/js-sdk#getvisitorcode), as long as you add the corresponding experiment assignments to `window.kameleoonQueue`.
* You can insert the returned tracking code directly into an HTML `