// Import classes:
import com.onesignal.client.ApiClient;
import com.onesignal.client.ApiException;
import com.onesignal.client.Configuration;
import com.onesignal.client.auth.*;
import com.onesignal.client.models.*;
import com.onesignal.client.api.DefaultApi;

public class Example {
  private static final String appId = "YOUR_APP_ID";
  private static final String appKeyToken = "YOUR_APP_KEY";
  private static final String userKeyToken = "YOUR_USER_TOKEN";

  private static Notification createNotification() {
    Notification notification = new Notification();
    notification.setAppId(appId);
    notification.setIsChrome(true);
    notification.setIsAnyWeb(true);
    notification.setIncludedSegments(Arrays.asList(new String[]{"Subscribed Users"}));
    StringMap contentStringMap = new StringMap();
    contentStringMap.en("Test");
    notification.setContents(contentStringMap);

    return notification;
  }

  public static void main(String[] args) {
    // Setting up the client
    ApiClient defaultClient = Configuration.getDefaultApiClient();
    HttpBearerAuth appKey = (HttpBearerAuth) defaultClient.getAuthentication("app_key");
    appKey.setBearerToken(appKeyToken);
    HttpBearerAuth userKey = (HttpBearerAuth) defaultClient.getAuthentication("user_key");
    userKey.setBearerToken(userKeyToken);
    api = new DefaultApi(defaultClient);

    // Setting up the notification
    Notification notification = createNotification();

    // Sending the request
    CreateNotificationSuccessResponse response = api.createNotification(notification);

    // Checking the result
    System.out.print(response.getId();
  }
}