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Azure SDK for Java Reference Documentation

Current version is 1.0.0-beta.4, click here for the index

Azure Web PubSub service client library for Java

See: Description

Package Description
Package containing classes for creating clients to perform operations on the Azure Web Pub Sub Service.
Package containing model classes for use with the Azure Web Pub Sub Service.
Current version is 1.0.0-beta.4, click here for the index

Azure Web PubSub service client library for Java

Azure Web PubSub service client library for Java allows sending messages to Web PubSub. Azure Web PubSub service enables you to build real-time messaging web applications using WebSockets and the publish-subscribe pattern. Any platform supporting WebSocket APIs can connect to the service easily, e.g. web pages, mobile applications, edge devices, etc. The service manages the WebSocket connections for you and allows up to 100K concurrent connections. It provides powerful APIs for you to manage these clients and deliver real-time messages.

Any scenario that requires real-time publish-subscribe messaging between server and clients or among clients, can use Azure Web PubSub service. Traditional real-time features that often require polling from server or submitting HTTP requests, can also use Azure Web PubSub service.

Source code | Product Documentation | Samples

Getting started


Include the Package


Create a Web PubSub client using connection string

WebPubSubServiceClient webPubSubServiceClient = new WebPubSubServiceClientBuilder()

Create a Web PubSub client using access key

WebPubSubServiceClient webPubSubServiceClient = new WebPubSubServiceClientBuilder()
    .credential(new AzureKeyCredential("{access-key}"))
    .endpoint("<Insert endpoint from Azure Portal>")

Key concepts


Hub is a logic set of connections. All connections to Web PubSub connect to a specific hub. Messages that are broadcast to the hub are dispatched to all connections to that hub. For example, hub can be used for different applications, different applications can share one Azure Web PubSub service by using different hub names.


Group allow broadcast messages to a subset of connections to the hub. You can add and remove users and connections as needed. A client can join multiple groups, and a group can contain multiple clients.


Connections to Web PubSub can belong to one user. A user might have multiple connections, for example when a single user is connected across multiple devices or multiple browser tabs.


Connections, represented by a connection id, represent an individual websocket connection to the Web PubSub service. Connection id is always unique.


A message is either an UTF-8 encoded string or raw binary data.


Broadcast message to entire hub

webPubSubServiceClient.sendToAll("Hello world!", "text/plain");

Broadcast message to a group

webPubSubServiceClient.sendToGroup("java", "Hello Java!", "text/plain");

Send message to a connection

webPubSubServiceClient.sendToConnection("myconnectionid", "Hello connection!", "text/plain");

Send message to a user

webPubSubServiceClient.sendToUser("Andy", "Hello Andy!", "text/plain");


Enable client logging

You can set the AZURE_LOG_LEVEL environment variable to view logging statements made in the client library. For example, setting AZURE_LOG_LEVEL=2 would show all informational, warning, and error log messages. The log levels can be found here: log levels.

Default HTTP Client

All client libraries by default use the Netty HTTP client. Adding the above dependency will automatically configure the client library to use the Netty HTTP client. Configuring or changing the HTTP client is detailed in the HTTP clients wiki.

Default SSL library

All client libraries, by default, use the Tomcat-native Boring SSL library to enable native-level performance for SSL operations. The Boring SSL library is an uber jar containing native libraries for Linux / macOS / Windows, and provides better performance compared to the default SSL implementation within the JDK. For more information, including how to reduce the dependency size, refer to the performance tuning section of the wiki.

Next steps


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.

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 with any additional questions or comments.


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