---
name: azure-communication-common-java
description: Azure Communication Services common utilities for Java. Use when working with CommunicationTokenCredential, user identifiers, token refresh, or shared authentication across ACS services.
package: com.azure:azure-communication-common
---
# Azure Communication Common (Java)
Shared authentication utilities and data structures for Azure Communication Services.
## Installation
```xml
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-communication-common</artifactId>
<version>1.4.0</version>
</dependency>
```
## Key Concepts
| Class | Purpose |
|-------|---------|
| `CommunicationTokenCredential` | Authenticate users with ACS services |
| `CommunicationTokenRefreshOptions` | Configure automatic token refresh |
| `CommunicationUserIdentifier` | Identify ACS users |
| `PhoneNumberIdentifier` | Identify PSTN phone numbers |
| `MicrosoftTeamsUserIdentifier` | Identify Teams users |
| `UnknownIdentifier` | Generic identifier for unknown types |
## CommunicationTokenCredential
### Static Token (Short-lived Clients)
```java
import com.azure.communication.common.CommunicationTokenCredential;
// Simple static token - no refresh
String userToken = "<user-access-token>";
CommunicationTokenCredential credential = new CommunicationTokenCredential(userToken);
// Use with Chat, Calling, etc.
ChatClient chatClient = new ChatClientBuilder()
.endpoint("https://<resource>.communication.azure.com")
.credential(credential)
.buildClient();
```
### Proactive Token Refresh (Long-lived Clients)
```java
import com.azure.communication.common.CommunicationTokenRefreshOptions;
import java.util.concurrent.Callable;
// Token refresher callback - called when token is about to expire
Callable<String> tokenRefresher = () -> {
// Call your server to get a fresh token
return fetchNewTokenFromServer();
};
// With proactive refresh
CommunicationTokenRefreshOptions refreshOptions = new CommunicationTokenRefreshOptions(tokenRefresher)
.setRefreshProactively(true) // Refresh before expiry
.setInitialToken(currentToken); // Optional initial token
CommunicationTokenCredential credential = new CommunicationTokenCredential(refreshOptions);
```
### Async Token Refresh
```java
import java.util.concurrent.CompletableFuture;
// Async token fetcher
Callable<String> asyncRefresher = () -> {
CompletableFuture<String> future = fetchTokenAsync();
return future.get(); // Block until token is available
};
CommunicationTokenRefreshOptions options = new CommunicationTokenRefreshOptions(asyncRefresher)
.setRefreshProactively(true);
CommunicationTokenCredential credential = new CommunicationTokenCredential(options);
```
## Entra ID (Azure AD) Authentication
```java
import com.azure.identity.InteractiveBrowserCredentialBuilder;
import com.azure.communication.common.EntraCommunicationTokenCredentialOptions;
import java.util.Arrays;
import java.util.List;
// For Teams Phone Extensibility
InteractiveBrowserCredential entraCredential = new InteractiveBrowserCredentialBuilder()
.clientId("<your-client-id>")
.tenantId("<your-tenant-id>")
.redirectUrl("<your-redirect-uri>")
.build();
String resourceEndpoint = "https://<resource>.communication.azure.com";
List<String> scopes = Arrays.asList(
"https://auth.msft.communication.azure.com/TeamsExtension.ManageCalls"
);
EntraCommunicationTokenCredentialOptions entraOptions =
new EntraCommunicationTokenCredentialOptions(entraCredential, resourceEndpoint)
.setScopes(scopes);
CommunicationTokenCredential credential = new CommunicationTokenCredential(entraOptions);
```
## Communication Identifiers
### CommunicationUserIdentifier
```java
import com.azure.communication.common.CommunicationUserIdentifier;
// Create identifier for ACS user
CommunicationUserIdentifier user = new CommunicationUserIdentifier("8:acs:resource-id_user-id");
// Get raw ID
String rawId = user.getId();
```
### PhoneNumberIdentifier
```java
import com.azure.communication.common.PhoneNumberIdentifier;
// E.164 format phone number
PhoneNumberIdentifier phone = new PhoneNumberIdentifier("+14255551234");
String phoneNumber = phone.getPhoneNumber(); // "+14255551234"
String rawId = phone.getRawId(); // "4:+14255551234"
```
### MicrosoftTeamsUserIdentifier
```java
import com.azure.communication.common.MicrosoftTeamsUserIdentifier;
// Teams user identifier
MicrosoftTeamsUserIdentifier teamsUser = new MicrosoftTeamsUserIdentifier("<teams-user-id>")
.setCloudEnvironment(CommunicationCloudEnvironment.PUBLIC);
// For anonymous Teams users
MicrosoftTeamsUserIdentifier anonymousTeamsUser = new MicrosoftTeamsUserIdentifier("<teams-user-id>")
.setAnonymous(true);
```
### UnknownIdentifier
```java
import com.azure.communication.common.UnknownIdentifier;
// For identifiers of unknown type
UnknownIdentifier unknown = new UnknownIdentifier("some-raw-id");
```
## Identifier Parsing
```java
import com.azure.communication.common.CommunicationIdentifier;
import com.azure.communication.common.CommunicationIdentifierModel;
// Parse raw ID to appropriate type
public CommunicationIdentifier parseIdentifier(String rawId) {
if (rawId.startsWith("8:acs:")) {
return new CommunicationUserIdentifier(rawId);
} else if (rawId.startsWith("4:")) {
String phone = rawId.substring(2);
return new PhoneNumberIdentifier(phone);
} else if (rawId.startsWith("8:orgid:")) {
String teamsId = rawId.substring(8);
return new MicrosoftTeamsUserIdentifier(teamsId);
} else {
return new UnknownIdentifier(rawId);
}
}
```
## Type Checking Identifiers
```java
import com.azure.communication.common.CommunicationIdentifier;
public void processIdentifier(CommunicationIdentifier identifier) {
if (identifier instanceof CommunicationUserIdentifier) {
CommunicationUserIdentifier user = (CommunicationUserIdentifier) identifier;
System.out.println("ACS User: " + user.getId());
} else if (identifier instanceof PhoneNumberIdentifier) {
PhoneNumberIdentifier phone = (PhoneNumberIdentifier) identifier;
System.out.println("Phone: " + phone.getPhoneNumber());
} else if (identifier instanceof MicrosoftTeamsUserIdentifier) {
MicrosoftTeamsUserIdentifier teams = (MicrosoftTeamsUserIdentifier) identifier;
System.out.println("Teams User: " + teams.getUserId());
System.out.println("Anonymous: " + teams.isAnonymous());
} else if (identifier instanceof UnknownIdentifier) {
UnknownIdentifier unknown = (UnknownIdentifier) identifier;
System.out.println("Unknown: " + unknown.getId());
}
}
```
## Token Access
```java
import com.azure.core.credential.AccessToken;
// Get current token (for debugging/logging - don't expose!)
CommunicationTokenCredential credential = new CommunicationTokenCredential(token);
// Sync access
AccessToken accessToken = credential.getToken();
System.out.println("Token expires: " + accessToken.getExpiresAt());
// Async access
credential.getTokenAsync()
.subscribe(token -> {
System.out.println("Token: " + token.getToken().substring(0, 20) + "...");
System.out.println("Expires: " + token.getExpiresAt());
});
```
## Dispose Credential
```java
// Clean up when done
credential.close();
// Or use try-with-resources
try (CommunicationTokenCredential cred = new CommunicationTokenCredential(options)) {
// Use credential
chatClient.doSomething();
}
```
## Cloud Environments
```java
import com.azure.communication.common.CommunicationCloudEnvironment;
// Available environments
CommunicationCloudEnvironment publicCloud = CommunicationCloudEnvironment.PUBLIC;
CommunicationCloudEnvironment govCloud = CommunicationCloudEnvironment.GCCH;
CommunicationCloudEnvironment dodCloud = CommunicationCloudEnvironment.DOD;
// Set on Teams identifier
MicrosoftTeamsUserIdentifier teamsUser = new MicrosoftTeamsUserIdentifier("<user-id>")
.setCloudEnvironment(CommunicationCloudEnvironment.GCCH);
```
## Environment Variables
```bash
AZURE_COMMUNICATION_ENDPOINT=https://<resource>.communication.azure.com
AZURE_COMMUNICATION_USER_TOKEN=<user-access-token>
```
## Best Practices
1. **Proactive Refresh** - Always use `setRefreshProactively(true)` for long-lived clients
2. **Token Security** - Never log or expose full tokens
3. **Close Credentials** - Dispose of credentials when no longer needed
4. **Error Handling** - Handle token refresh failures gracefully
5. **Identifier Types** - Use specific identifier types, not raw strings
## Common Usage Patterns
```java
// Pattern: Create credential for Chat/Calling client
public ChatClient createChatClient(String token, String endpoint) {
CommunicationTokenRefreshOptions refreshOptions =
new CommunicationTokenRefreshOptions(this::refreshToken)
.setRefreshProactively(true)
.setInitialToken(token);
CommunicationTokenCredential credential =
new CommunicationTokenCredential(refreshOptions);
return new ChatClientBuilder()
.endpoint(endpoint)
.credential(credential)
.buildClient();
}
private String refreshToken() {
// Call your token endpoint
return tokenService.getNewToken();
}
```
## Trigger Phrases
- "ACS authentication", "communication token credential"
- "user access token", "token refresh"
- "CommunicationUserIdentifier", "PhoneNumberIdentifier"
- "Azure Communication Services authentication"
