Create Tasks from Phone Calls using TwiML: Receive an Incoming Call

We've seen how to create Tasks using the TaskRouter REST API and how to accept a Task Reservation using both the REST API and Assignment Callback instructions. TaskRouter also introduces new TwiML instructions that you can use to create a Task from a Twilio phone call.

Receive an Incoming Call

To receive an incoming phone call, we first need a Twilio phone number. In this example we'll use a US toll-free number, but you can use a Voice capable number from any country.

Before purchasing or setting up the phone number, we need to add on to our TwilioTaskRouterServlet to handle incoming calls:

TwilioTaskRouterServlet.java

1import java.io.IOException;
2
3import javax.servlet.http.HttpServlet;
4import javax.servlet.http.HttpServletRequest;
5import javax.servlet.http.HttpServletResponse;
6
7import com.twilio.Twilio;
8import com.twilio.rest.taskrouter.v1.workspace.Task;
9import com.twilio.rest.taskrouter.v1.workspace.task.Reservation;
10import com.twilio.twiml.Gather;
11import com.twilio.twiml.Say;
12import com.twilio.twiml.TwiMLException;
13import com.twilio.twiml.VoiceResponse;
14
15public class TwilioTaskRouterServlet extends HttpServlet {
16
17  private String accountSid;
18  private String authToken;
19  private String workspaceSid;
20  private String workflowSid;
21
22  @Override
23  public void init() {
24    accountSid = this.getServletConfig().getInitParameter("AccountSid");
25    authToken = this.getServletConfig().getInitParameter("AuthToken");
26    workspaceSid = this.getServletConfig().getInitParameter("WorkspaceSid");
27    workflowSid = this.getServletConfig().getInitParameter("WorkflowSid");
28
29    Twilio.init(accountSid, authToken);
30  }
31
32  // service() responds to both GET and POST requests.
33  // You can also use doGet() or doPost()
34  @Override
35  public void service(final HttpServletRequest request, final HttpServletResponse response)
36      throws IOException {
37    if (request.getPathInfo() == null || request.getPathInfo().isEmpty()) {
38      return;
39    }
40
41    if (request.getPathInfo().equals("/assignment_callback")) {
42      response.setContentType("application/json");
43      response.getWriter().print("{\"instruction\":\"accept\"}");
44    } else if (request.getPathInfo().equals("/create_task")) {
45      response.setContentType("application/json");
46      response.getWriter().print(createTask());
47    } else if (request.getPathInfo().equals("/accept_reservation")) {
48      response.setContentType("application/json");
49      final String taskSid = request.getParameter("TaskSid");
50      final String reservationSid = request.getParameter("ReservationSid");
51      response.getWriter().print(acceptReservation(taskSid, reservationSid));
52    } else if (request.getPathInfo().equals("/incoming_call")) {
53      response.setContentType("application/xml");
54      response.getWriter().print(handleIncomingCall());
55    }
56  }
57
58  public String createTask() {
59    String attributes = "{\"selected_language\":\"es\"}";
60
61    Task task = Task.creator(workspaceSid, attributes, workflowSid).create();
62
63    return "{\"task_sid\":\"" + task.getSid() + "\"}";
64  }
65
66  public String acceptReservation(final String taskSid, final String reservationSid) {
67    Reservation reservation = Reservation.updater(workspaceSid, taskSid, reservationSid)
68        .setReservationStatus(Reservation.Status.ACCEPTED).update();
69
70    return "{\"worker_name\":\"" + reservation.getWorkerName() + "\"}";
71  }
72
73  public String handleIncomingCall() {
74    VoiceResponse twiml =
75        new VoiceResponse.Builder()
76            .gather(new Gather.Builder()
77                .say(new Say.Builder("Para Español oprime el uno.").language(Say.Language.ES)
78                    .build())
79                .say(new Say.Builder("For English, please hold or press two.")
80                    .language(Say.Language.EN).build())
81                .numDigits(1).timeout(5).build())
82            .build();
83
84    try {
85      return twiml.toXml();
86    } catch (TwiMLException e) {
87      return "Error creating TwiML: " + e.getMessage();
88    }
89  }
90}

You can use the Buy Numbers section of the Twilio Voice and Messaging web portal to purchase a new phone number, or use an existing Twilio phone number. Open the phone number details page and point the Voice Request URL at your new endpoint:

TaskRouter Quickstart showing phone number properties and request URLs for voice and messaging.

Using any phone, call the Twilio number. You will be prompted to press one for Spanish or two for English. However, when you press a digit, you'll hear an error message. That's because our <Gather> verb is pointing to another endpoint, enqueue_call, which we haven't implemented yet. In the next step we'll add the required endpoint and use it to create a new Task based on the language selected by the caller.

Next: Create a Task using Enqueue »