JRE Ampli Wrapper

Note

This page covers the JRE Java and Kotlin runtimes. All (Itly) runtimes have been deprecated. If you are still using an (Itly) runtime, see the migration guide to ugrade to the newest runtime. Docs for the Itly version are available here.

Amplitude Data supports tracking analytics events from JRE programs written in Java (6 and above).

In Java, the tracking library exposes a type-safe function for every event in your team’s tracking plan. The function’s arguments correspond to the event’s properties and are strongly typed to allow for code completion and compile-time checks.

Tip

See example apps that use the JRE Java and Kotlin runtimes on GitHub.

Installation

These instructions are also available from the Implementation page of your Amplitude Data workspace.

Install the Ampli CLI

If you haven't installed the Ampli CLI, install it now.

Install dependencies

If you haven't already, install the core Amplitude SDK dependencies.

JavaKotlin

• Inside <dependencies>, add:

<dependency>
    <groupId>com.amplitude</groupId>
    <artifactId>java-sdk</artifactId>
    <version>1.6.0</version>
</dependency>
<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20201115</version>
</dependency>

implementation 'com.amplitude:java-sdk:1.6.0'
implementation 'org.json:json:20201115'

Pull the SDK into your project

At the project root, run pull command.

ampli pull

This prompts you to log in to your workspace and select a source.

JavaKotlin

➜ ampli pull sourcename
Ampli project is not initialized. No existing `ampli.json` configuration found.
? Create a new Ampli project here? Yes
Organization: Amplitude
Workspace: My Workspace
Source: sourcename
Runtime: JRE - Java
Branch: main
Pulling latest version (1.0.0)...
Tracking library generated successfully.
Path: ./src/itly

➜ ampli pull sourcename
Ampli project is not initialized. No existing `ampli.json` configuration found.
? Create a new Ampli project here? Yes
Organization: Amplitude
Workspace: My Workspace
Source: sourcename
Runtime: JRE - Kotlin
Branch: main
Pulling latest version (1.0.0)...
Tracking library generated successfully.
Path: ./src/itly

API

Load

Initialize Ampli in your code. The load() method accepts configuration option arguments:

JavaKotlin

import com.amplitude.ampli.*;

Ampli.getInstance().load(new LoadOptions()
  .setEnvironment(Ampli.Environment.PRODUCTION)
);

import com.amplitude.ampli.*

ampli.load(LoadOptions(
  environment = Ampli.Environment.PRODUCTION
));

Arg	Description
LoadOptions	Optional. Defaults to false. Specifies configuration options for the Ampli Wrapper.
disabled	Optional. Specifies whether the Ampli Wrapper does any work. When true, all calls to the Ampli Wrapper are no-ops. Useful in local or development environments.
environment	Optional. Defaults to development. Specifies the environment the Ampli Wrapper runs in: either production or development. Environment determines which Access Token is used to load the underlying analytics provider libraries. The option also determines safe defaults for handling event validation errors. In production, when the SDK detects an invalid event, it logs an error but stills let the event through. In development, the SDK throws an exception to alert you that something is wrong.
client	Optional. Specifies an Amplitude instance. By default Ampli creates an instance for you.
apiKey	Optional. Specifies an API Key. This option overrides the default, which is the API Key configured in your tracking plan.

Identify

Call identify() to set user properties.

Just as Ampli creates types for events and their properties, it creates types for user properties.

The identify() function accepts an optional userId, optional user properties, and optional options.

For example your tracking plan contains a user property called userProp. The property's type is a string.

JavaKotlin

Ampli.getInstance().identify("user-id", Identify.builder()
  .userProp("A user property")
  .build()
);

ampli.identify("user-id", Identify(
    userProp = "A trait associated with this user"
))

The options argument allows you to pass Amplitude fields for this call, such as deviceId.

JavaKotlin

Ampli.getInstance().identify(
  userId,
  Identify.builder().userProp("A trait associated with this user"),.build(),
  new EventOptions().setDeviceId(deviceId).setUserId("some-user"),
);

ampli.identify(userId, Identify(
    userProp = "A trait associated with this user",
  )
  EventOptions(deviceId = "device-id"),
)

Group

Feature availability

This feature is available in Growth and Enterprise accounts with the Accounts add-on.

Call setGroup() to associate a user with their group (for example, their department or company). The setGroup() function accepts a required groupType, and groupName.

JavaKotlin

Ampli.getInstance().setGroup("user-id", "GroupType", "GroupName");

ampli.setGroup("user-id", "GroupType", "GroupName");

Amplitude supports assigning users to groups and performing queries, such as Count by Distinct, on those groups. If at least one member of the group has performed the specific event, then the count includes the group.

For example, you want to group your users based on what organization they're in by using an 'orgId'. Joe is in 'orgId' '10', and Sue is in 'orgId' '15'. Sue and Joe both perform a certain event. You can query their organizations in the Event Segmentation Chart.

When setting groups, define a groupType and groupName. In the previous example, 'orgId' is the groupType and '10' and '15' are the values for groupName. Another example of a groupType could be 'sport' with groupName values like 'tennis' and 'baseball'.

Setting a group also sets the groupType:groupName as a user property, and overwrites any existing groupName value set for that user's groupType, and the corresponding user property value. groupType is a string, and groupName can be either a string or an array of strings to indicate that a user is in multiple groups.

For example, if Joe is in 'orgId' '10' and '20', then the groupName is '[10, 20]').

Your code might look like this:

JavaKotlin

Ampli.getInstance().setGroup("user-id", "orgID", ["10", "20"]);

ampli.setGroup("user-id", "orgId", ["10", "20"]);

Track

To track an event, call the event's corresponding function. Every event in your tracking plan gets its own function in the Ampli Wrapper. The call is structured like this:

JavaKotlin

Ampli.getInstance().track(String userId, Event event, EventOptions options, MiddlewareExtra extra)

ampli.track(userId: String, event: Event, options: EventOptions, extra: MiddlewareExtra)

The options argument allows you to pass Amplitude fields, like price, quantity and revenue. The extra argument lets you pass data to middleware.

For example, in the code snippet below, your tracking plan contains an event called songPlayed. The event is defined with two required properties: songId and songFavorited. The property type for songId is string, and songFavorited is a boolean.

The event has an Amplitude field defined: deviceId. Learn more about Amplitude fields here. The event has one MiddlewareExtra defined: extra. Learn more about Middleware.

JavaKotlin

MiddlewareExtra extra = new MiddlewareExtra();
extra.put("extra-key", "extra-value");

Ampli.getInstance().songPlayed("user-id",
  SongPlayed.builder()
    .songId('songId') // String
    .songFavorited(true) // Boolean
    .build(),
  new EventOptions().setDeviceId(deviceId),
  extra
);

ampli.songPlayed("user-id",
  SongPlayed(
    songId = 'songId', // String,
    songFavorited = true, // Boolean
  ),
  options = EventOptions(deviceId = "device-id"),
  extra = MiddlewareExtra(mapOf("extra-key" to "extra-value")
);

Ampli also generates a class for each event.

JavaKotlin

SongPlayed event = SongPlayed.builder()
  .songId('songId') // String
  .songFavorited(true) // Boolean
  .build()

val myEventObject = SongPlayed(
  songId = 'songId', // String,
  songFavorited = true, // Boolean
);

Send Event objects using the generic track method.

JavaKotlin

Ampli.getInstance().track("user-id", SongPlayed.builder()
  .songId('songId') // String
  .songFavorited(true) // Boolean
  .build()
);

ampli.track("user-id", SongPlayed(
  songId = 'songId', // String,
  songFavorited = true, // Boolean
);

Verify implementation status

Verify that events are implemented in your code with the status command:

ampli status

To update the implementation status in your tracking plan use the --update flag or -u:

ampli status -u

The output displays status and indicates what events are missing.

➜ ampli status
✘ Verifying event tracking implementation in source code
 ✔ Song Played (1 location)
 ✘ Song Stopped Called when a user stops playing a song.
Events Tracked: 2 missed, 3 total

Learn more about ampli status.

Migrating from an Itly JRE Runtime

Migrate from an Itly JRE runtime to Ampli by following these steps.

1. Remove legacy Itly dependencies from your project. This includes anything with a ly.iterative.itly.

   implementation "ly.iterative.itly:sdk-jvm:$itlySdkVersion"
   implementation "ly.iterative.itly:plugin-iteratively:$itlySdkVersion"
   implementation "ly.iterative.itly:plugin-schema-validator:$itlySdkVersion"
   implementation "ly.iterative.itly:plugin-segment-jvm:$itlySdkVersion"
   

2. Add Amplitude dependencies.

   implementation 'com.amplitude:java-sdk:1.6.0'
   implementation 'org.json:json:20201115'
   

3. Pull the latest Ampli Wrapper.

   ampli pull
   

4. Check your Ampli Wrapper path.

   ampli pull prints the download location of the SDK. If the path contains itly, you can update the Path by hand in the ampli.json file, or pull again using the --path parameter: ampli pull -p ./path/to/ampli.

5. Find and replace:

   Kotlin and Java:

   • import ly.iterative.itly.* => import com.amplitude.ampli.*
   • itly. => ampli.
   • itly.group(groupId) => ampli.setGroup(groupType, groupValue)

   Kotlin only:

   • Itly.load() => ampli.load()
   • Itly. => ampli.

   Java only:

   • Itly.getInstance().load() => Ampli.getInstance().load()
   • Itly. => Ampli.

6. See updated Event tracking details on your Implementation page in the web app.

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Last update: 2022-07-19