Azure Communication Callautomation Java

import com.azure.communication.callautomation.CallAutomationClient;import com.azure.communication.callautomation.CallAutomationClientBuilder;import com.azure.core.credential.TokenCredential;import com.azure.identity.AzureIdentityEnvVars;import com.azure.identity.DefaultAzureCredentialBuilder;import com.azure.identity.ManagedIdentityCredentialBuilder;
// Local dev: DefaultAzureCredential. Production: set AZURE_TOKEN_CREDENTIALS=prod or AZURE_TOKEN_CREDENTIALS=<specific_credential>TokenCredential credential = new DefaultAzureCredentialBuilder()    .requireEnvVars(AzureIdentityEnvVars.AZURE_TOKEN_CREDENTIALS)    .build();// Or use a specific credential directly in production:// See https://learn.microsoft.com/java/api/overview/azure/identity-readme?view=azure-java-stable#credential-classes// TokenCredential credential = new ManagedIdentityCredentialBuilder().build();
// With DefaultAzureCredentialCallAutomationClient client = new CallAutomationClientBuilder()    .endpoint("https://<resource>.communication.azure.com")    .credential(credential)    .buildClient();
// With connection stringCallAutomationClient client = new CallAutomationClientBuilder()    .connectionString("<connection-string>")    .buildClient();

import com.azure.communication.callautomation.models.*;import com.azure.communication.common.CommunicationUserIdentifier;import com.azure.communication.common.PhoneNumberIdentifier;
// Call to PSTN numberPhoneNumberIdentifier target = new PhoneNumberIdentifier("+14255551234");PhoneNumberIdentifier caller = new PhoneNumberIdentifier("+14255550100");
CreateCallOptions options = new CreateCallOptions(    new CommunicationUserIdentifier("<user-id>"),  // Source    List.of(target))                                // Targets    .setSourceCallerId(caller)    .setCallbackUrl("https://your-app.com/api/callbacks");
CreateCallResult result = client.createCall(options);String callConnectionId = result.getCallConnectionProperties().getCallConnectionId();

// From Event Grid webhook - IncomingCall eventString incomingCallContext = "<incoming-call-context-from-event>";
AnswerCallOptions options = new AnswerCallOptions(    incomingCallContext,    "https://your-app.com/api/callbacks");
AnswerCallResult result = client.answerCall(options);CallConnection callConnection = result.getCallConnection();

CallConnection callConnection = client.getCallConnection(callConnectionId);CallMedia callMedia = callConnection.getCallMedia();
// Play text-to-speechTextSource textSource = new TextSource()    .setText("Welcome to Contoso. Press 1 for sales, 2 for support.")    .setVoiceName("en-US-JennyNeural");
PlayOptions playOptions = new PlayOptions(    List.of(textSource),    List.of(new CommunicationUserIdentifier("<target-user>")));
callMedia.play(playOptions);
// Play audio fileFileSource fileSource = new FileSource()    .setUrl("https://storage.blob.core.windows.net/audio/greeting.wav");
callMedia.play(new PlayOptions(List.of(fileSource), List.of(target)));

// Recognize DTMF tonesDtmfTone stopTones = DtmfTone.POUND;
CallMediaRecognizeDtmfOptions recognizeOptions = new CallMediaRecognizeDtmfOptions(    new CommunicationUserIdentifier("<target-user>"),    5)  // Max tones to collect    .setInterToneTimeout(Duration.ofSeconds(5))    .setStopTones(List.of(stopTones))    .setInitialSilenceTimeout(Duration.ofSeconds(15))    .setPlayPrompt(new TextSource().setText("Enter your account number followed by pound."));
callMedia.startRecognizing(recognizeOptions);

// Speech recognition with AICallMediaRecognizeSpeechOptions speechOptions = new CallMediaRecognizeSpeechOptions(    new CommunicationUserIdentifier("<target-user>"))    .setEndSilenceTimeout(Duration.ofSeconds(2))    .setSpeechLanguage("en-US")    .setPlayPrompt(new TextSource().setText("How can I help you today?"));
callMedia.startRecognizing(speechOptions);

CallRecording callRecording = client.getCallRecording();
// Start recordingStartRecordingOptions recordingOptions = new StartRecordingOptions(    new ServerCallLocator("<server-call-id>"))    .setRecordingChannel(RecordingChannel.MIXED)    .setRecordingContent(RecordingContent.AUDIO_VIDEO)    .setRecordingFormat(RecordingFormat.MP4);
RecordingStateResult recordingResult = callRecording.start(recordingOptions);String recordingId = recordingResult.getRecordingId();
// Pause/resume/stopcallRecording.pause(recordingId);callRecording.resume(recordingId);callRecording.stop(recordingId);
// Download recording (after RecordingFileStatusUpdated event)callRecording.downloadTo(recordingUrl, Paths.get("recording.mp4"));

CallConnection callConnection = client.getCallConnection(callConnectionId);
CommunicationUserIdentifier participant = new CommunicationUserIdentifier("<user-id>");AddParticipantOptions addOptions = new AddParticipantOptions(participant)    .setInvitationTimeout(Duration.ofSeconds(30));
AddParticipantResult result = callConnection.addParticipant(addOptions);

// Blind transferPhoneNumberIdentifier transferTarget = new PhoneNumberIdentifier("+14255559999");TransferCallToParticipantResult result = callConnection.transferCallToParticipant(transferTarget);

import com.azure.communication.callautomation.CallAutomationEventParser;import com.azure.communication.callautomation.models.events.*;
// In your webhook endpointpublic void handleCallback(String requestBody) {    List<CallAutomationEventBase> events = CallAutomationEventParser.parseEvents(requestBody);        for (CallAutomationEventBase event : events) {        if (event instanceof CallConnected) {            CallConnected connected = (CallConnected) event;            System.out.println("Call connected: " + connected.getCallConnectionId());        } else if (event instanceof RecognizeCompleted) {            RecognizeCompleted recognized = (RecognizeCompleted) event;            // Handle DTMF or speech recognition result            DtmfResult dtmfResult = (DtmfResult) recognized.getRecognizeResult();            String tones = dtmfResult.getTones().stream()                .map(DtmfTone::toString)                .collect(Collectors.joining());            System.out.println("DTMF received: " + tones);        } else if (event instanceof PlayCompleted) {            System.out.println("Audio playback completed");        } else if (event instanceof CallDisconnected) {            System.out.println("Call ended");        }    }}

// Hang up for all participantscallConnection.hangUp(true);
// Hang up only this legcallConnection.hangUp(false);

import com.azure.core.exception.HttpResponseException;
try {    client.answerCall(options);} catch (HttpResponseException e) {    if (e.getResponse().getStatusCode() == 404) {        System.out.println("Call not found or already ended");    } else if (e.getResponse().getStatusCode() == 400) {        System.out.println("Invalid request: " + e.getMessage());    }}