azure-communication-common

Azure Communication Common client library for Android

This package contains common code for Azure Communication Service libraries.

Source code | API reference documentation | Product documentation

Getting started

Prerequisites

• You must have an Azure subscription and a Communication Services resource to use this library.
• The client libraries natively target Android API level 21. Your application's minSdkVersion must be set to 21 or higher to use this library.
• The library is written in Java 8. Your application must be built with Android Gradle Plugin 3.0.0 or later, and must be configured to enable Java 8 language desugaring to use this library. Java 8 language features that require a target API level >21 are not used, nor are any Java 8+ APIs that would require the Java 8+ API desugaring provided by Android Gradle plugin 4.0.0.

Versions available

The current version of this library is 1.2.1.

Install the library

To install the Azure client libraries for Android, add them as dependencies within your Gradle or Maven build scripts.

Add a dependency with Gradle

To import the library into your project using the Gradle build system, follow the instructions in Add build dependencies:

Add an implementation configuration to the dependencies block of your app's build.gradle or build.gradle.kts file, specifying the library's name and the version you wish to use:

// build.gradle
dependencies {
    ...
    implementation "com.azure.android:azure-communication-common:1.2.1"
}

// build.gradle.kts
dependencies {
    ...
    implementation("com.azure.android:azure-communication-common:1.2.1")
}

Add a dependency with Maven

To import the library into your project using the Maven build system, add it to the dependencies section of your app's pom.xml file, specifying its artifact ID and the version you wish to use:

<dependency>
  <groupId>com.azure.android</groupId>
  <artifactId>azure-communication-common</artifactId>
  <version>1.2.1</version>
</dependency>

Key concepts

CommunicationTokenCredential

The CommunicationTokenCredential object is used to authenticate a user with Communication Services, such as Chat or Calling. It optionally provides an auto-refresh mechanism to ensure a continuously stable authentication state during communications.

Depending on your scenario, you may want to initialize the CommunicationTokenCredential with:

• a static token (suitable for short-lived clients used to e.g. send one-off Chat messages) or
• a callback function that ensures a continuous authentication state (ideal e.g. for long Calling sessions).

The tokens supplied to the CommunicationTokenCredential either through the constructor or via the token refresher callback can be obtained using the Azure Communication Identity library.

Examples

The following sections provide several code snippets showing different ways to use a CommunicationTokenCredential:

• Creating a credential with a static token
• Creating a credential that refreshes with a Callable
• Creating a credential that refreshes proactively
• Creating a credential with an initial value that refreshes proactively
• Getting a token asynchronously
• Invalidating a credential

Creating a credential with a static token

For short-lived clients, refreshing the token upon expiry is not necessary and CommunicationTokenCredential may be instantiated with a static token.

CommunicationTokenCredential userCredential = new CommunicationTokenCredential("eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjM2MDB9.adM-ddBZZlQ1WlN3pdPBOF5G4Wh9iZpxNP_fSvpF4cWs");

Creating a credential that refreshes on demand with a Callable

Alternatively, for long-lived clients, you can create a CommunicationTokenCredential with a callable to renew tokens if expired. Here we assume that we have a callable fetchTokenFromMyServerForUser that makes a network request to retrieve a token string for a user. It's necessary that the fetchTokenFromMyServerForUser function returns a valid token (with an expiration date set in the future) at all times. It will be called on a background thread.

Callable<String> tokenRefresher = () -> {
  return fetchTokenFromMyServerForUser();
};
CommunicationTokenRefreshOptions tokenRefreshOptions = new CommunicationTokenRefreshOptions(tokenRefresher)
            .setRefreshProactively(false);
CommunicationTokenCredential userCredential = new CommunicationTokenCredential(tokenRefreshOptions);

Creating a credential that refreshes proactively with a Callable

Optionally, you can enable proactive token refreshing where a fresh token will be acquired as soon as the previous token approaches expiry. Using this method, your requests are less likely to be blocked to acquire a fresh token.

CommunicationTokenRefreshOptions tokenRefreshOptions = new CommunicationTokenRefreshOptions(tokenRefresher)
    .setRefreshProactively(true);
CommunicationTokenCredential userCredential = new CommunicationTokenCredential(tokenRefreshOptions);

Creating a credential with an initial value that refreshes proactively

Passing initialToken is an optional optimization to skip the first call to Callable<String> tokenRefresher. You can use this to separate the boot from your application from subsequent token refresh cycles.

String token = "<Azure Communication Services user token>";
CommunicationTokenRefreshOptions tokenRefreshOptions = new CommunicationTokenRefreshOptions(tokenRefresher)
    .setRefreshProactively(true)
    .setInitialToken(token);
CommunicationTokenCredential userCredential = new CommunicationTokenCredential(tokenRefreshOptions);

Getting a token asynchronously

Calling getToken() will return a CompletableFuture<AccessToken>

CommunicationTokenCredential userCredential = new CommunicationTokenCredential(new CommunicationTokenRefreshOptions(tokenRefresher, false));
CompletableFuture<AccessToken> accessTokenFuture = userCredential.getToken();

Invalidating a credential

Each CommunicationTokenCredential instance uses a background thread for refreshing the cached token. To free up resources and facilitate garbage collection, dispose() must be called when the CommunicationTokenCredential instance is no longer used.

userCredential.dispose();

Troubleshooting

If you run into issues while using this library, please feel free to file an issue.

Next steps

• Read more about Communication user access tokens.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.