Java tutorial
/** Copyright 2014-2015 Amazon.com, Inc. or its affiliates. All Rights Reserved. Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance with the License. A copy of the License is located at http://aws.amazon.com/apache2.0/ or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.URL; import java.nio.charset.Charset; import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Calendar; import java.util.Collections; import java.util.Date; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.io.IOUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.amazon.speech.slu.Intent; import com.amazon.speech.slu.Slot; import com.amazon.speech.speechlet.IntentRequest; import com.amazon.speech.speechlet.LaunchRequest; import com.amazon.speech.speechlet.Session; import com.amazon.speech.speechlet.SessionEndedRequest; import com.amazon.speech.speechlet.SessionStartedRequest; import com.amazon.speech.speechlet.Speechlet; import com.amazon.speech.speechlet.SpeechletException; import com.amazon.speech.speechlet.SpeechletResponse; import com.amazon.speech.ui.OutputSpeech; import com.amazon.speech.ui.PlainTextOutputSpeech; import com.amazon.speech.ui.SsmlOutputSpeech; import com.amazon.speech.ui.Reprompt; import com.amazon.speech.ui.SimpleCard; /** * This sample shows how to create a Lambda function for handling Alexa Skill requests that: * * <ul> * <li><b>Web service</b>: communicate with an external web service to get events for specified days * in history (Wikipedia API)</li> * <li><b>Pagination</b>: after obtaining a list of events, read a small subset of events and wait * for user prompt to read the next subset of events by maintaining session state</li> * <p> * <li><b>Dialog and Session state</b>: Handles two models, both a one-shot ask and tell model, and * a multi-turn dialog model</li> * <li><b>SSML</b>: Using SSML tags to control how Alexa renders the text-to-speech</li> * </ul> * <p> * <h2>Examples</h2> * <p> * <b>One-shot model</b> * <p> * User: "Alexa, ask History Buff what happened on August thirtieth." * <p> * Alexa: "For August thirtieth, in 2003, [...] . Wanna go deeper in history?" * <p> * User: "No." * <p> * Alexa: "Good bye!" * <p> * * <b>Dialog model</b> * <p> * User: "Alexa, open History Buff" * <p> * Alexa: "History Buff. What day do you want events for?" * <p> * User: "August thirtieth." * <p> * Alexa: "For August thirtieth, in 2003, [...] . Wanna go deeper in history?" * <p> * User: "Yes." * <p> * Alexa: "In 1995, Bosnian war [...] . Wanna go deeper in history?" * <p> * User: "No." * <p> * Alexa: "Good bye!" * <p> */ public class SportsBroadcastsSpeechlet implements Speechlet { private static final Logger log = LoggerFactory.getLogger(SportsBroadcastsSpeechlet.class); /** * URL prefix to download history content from Wikipedia. */ private static final String URL_PREFIX = "https://en.wikipedia.org/w/api.php?action=query&prop=extracts" + "&format=json&explaintext=&exsectionformat=plain&redirects=&titles="; /** * Constant defining number of events to be read at one time. */ private static final int PAGINATION_SIZE = 3; /** * Length of the delimiter between individual events. */ private static final int DELIMITER_SIZE = 2; /** * Constant defining session attribute key for the event index. */ private static final String SESSION_INDEX = "index"; /** * Constant defining session attribute key for the event text key for date of events. */ private static final String SESSION_TEXT = "text"; /** * Constant defining session attribute key for the intent slot key for the date of events. */ private static final String SLOT_DAY = "day"; /** * Size of events from Wikipedia response. */ private static final int SIZE_OF_EVENTS = 10; /** * Array of month names. */ private static final String[] MONTH_NAMES = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" }; @Override public void onSessionStarted(final SessionStartedRequest request, final Session session) throws SpeechletException { log.info("onSessionStarted requestId={}, sessionId={}", request.getRequestId(), session.getSessionId()); // any initialization logic goes here } @Override public SpeechletResponse onLaunch(final LaunchRequest request, final Session session) throws SpeechletException { log.info("onLaunch requestId={}, sessionId={}", request.getRequestId(), session.getSessionId()); return getWelcomeResponse(); } @Override public SpeechletResponse onIntent(final IntentRequest request, final Session session) throws SpeechletException { log.info("onIntent requestId={}, sessionId={}", request.getRequestId(), session.getSessionId()); Intent intent = request.getIntent(); String intentName = intent.getName(); if ("GetFirstEventIntent".equals(intentName)) { return handleFirstEventRequest(intent, session); } else if ("GetNextEventIntent".equals(intentName)) { return handleNextEventRequest(session); } else if ("AMAZON.HelpIntent".equals(intentName)) { // Create the plain text output. String speechOutput = "With History Buff, you can get" + " historical events for any day of the year." + " For example, you could say today," + " or August thirtieth, or you can say exit. Now, which day do you want?"; String repromptText = "Which day do you want?"; return newAskResponse(speechOutput, false, repromptText, false); } else if ("AMAZON.StopIntent".equals(intentName)) { PlainTextOutputSpeech outputSpeech = new PlainTextOutputSpeech(); outputSpeech.setText("Goodbye"); return SpeechletResponse.newTellResponse(outputSpeech); } else if ("AMAZON.CancelIntent".equals(intentName)) { PlainTextOutputSpeech outputSpeech = new PlainTextOutputSpeech(); outputSpeech.setText("Goodbye"); return SpeechletResponse.newTellResponse(outputSpeech); } else { throw new SpeechletException("Invalid Intent"); } } @Override public void onSessionEnded(final SessionEndedRequest request, final Session session) throws SpeechletException { log.info("onSessionEnded requestId={}, sessionId={}", request.getRequestId(), session.getSessionId()); // any session cleanup logic would go here } /** * Function to handle the onLaunch skill behavior. * * @return SpeechletResponse object with voice/card response to return to the user */ private SpeechletResponse getWelcomeResponse() { String speechOutput = "History buff. What day do you want events for?"; // If the user either does not reply to the welcome message or says something that is not // understood, they will be prompted again with this text. String repromptText = "With History Buff, you can get historical events for any day of the year. " + " For example, you could say today, or August thirtieth." + " Now, which day do you want?"; return newAskResponse(speechOutput, false, repromptText, false); } /** * Function to accept an intent containing a Day slot (date object) and return the Calendar * representation of that slot value. If the user provides a date, then use that, otherwise use * today. The date is in server time, not in the user's time zone. So "today" for the user may * actually be tomorrow. * * @param intent * the intent object containing the day slot * @return the Calendar representation of that date */ private Calendar getCalendar(Intent intent) { Slot daySlot = intent.getSlot(SLOT_DAY); Date date; Calendar calendar = Calendar.getInstance(); if (daySlot != null && daySlot.getValue() != null) { DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-d"); try { date = dateFormat.parse(daySlot.getValue()); } catch (ParseException e) { date = new Date(); } } else { date = new Date(); } calendar.setTime(date); return calendar; } /** * Prepares the speech to reply to the user. Obtain events from Wikipedia for the date specified * by the user (or for today's date, if no date is specified), and return those events in both * speech and SimpleCard format. * * @param intent * the intent object which contains the date slot * @param session * the session object * @return SpeechletResponse object with voice/card response to return to the user */ private SpeechletResponse handleFirstEventRequest(Intent intent, Session session) { Calendar calendar = getCalendar(intent); String month = MONTH_NAMES[calendar.get(Calendar.MONTH)]; String date = Integer.toString(calendar.get(Calendar.DATE)); String speechPrefixContent = "<p>For " + month + " " + date + "</p> "; String cardPrefixContent = "For " + month + " " + date + ", "; String cardTitle = "Events on " + month + " " + date; ArrayList<String> events = getJsonEventsFromWikipedia(month, date); String speechOutput = ""; if (events.isEmpty()) { speechOutput = "There is a problem connecting to Wikipedia at this time." + " Please try again later."; // Create the plain text output SsmlOutputSpeech outputSpeech = new SsmlOutputSpeech(); outputSpeech.setSsml("<speak>" + speechOutput + "</speak>"); return SpeechletResponse.newTellResponse(outputSpeech); } else { StringBuilder speechOutputBuilder = new StringBuilder(); speechOutputBuilder.append(speechPrefixContent); StringBuilder cardOutputBuilder = new StringBuilder(); cardOutputBuilder.append(cardPrefixContent); for (int i = 0; i < PAGINATION_SIZE; i++) { speechOutputBuilder.append("<p>"); speechOutputBuilder.append(events.get(i)); speechOutputBuilder.append("</p> "); cardOutputBuilder.append(events.get(i)); cardOutputBuilder.append("\n"); } speechOutputBuilder.append(" Wanna go deeper in history?"); cardOutputBuilder.append(" Wanna go deeper in history?"); speechOutput = speechOutputBuilder.toString(); String repromptText = "With History Buff, you can get historical events for any day of the year." + " For example, you could say today, or August thirtieth." + " Now, which day do you want?"; // Create the Simple card content. SimpleCard card = new SimpleCard(); card.setTitle(cardTitle); card.setContent(cardOutputBuilder.toString()); // After reading the first 3 events, set the count to 3 and add the events // to the session attributes session.setAttribute(SESSION_INDEX, PAGINATION_SIZE); session.setAttribute(SESSION_TEXT, events); SpeechletResponse response = newAskResponse("<speak>" + speechOutput + "</speak>", true, repromptText, false); response.setCard(card); return response; } } /** * Prepares the speech to reply to the user. Obtains the list of events as well as the current * index from the session attributes. After getting the next set of events, increment the index * and store it back in session attributes. This allows us to obtain new events without making * repeated network calls, by storing values (events, index) during the interaction with the * user. * * @param session * object containing session attributes with events list and index * @return SpeechletResponse object with voice/card response to return to the user */ private SpeechletResponse handleNextEventRequest(Session session) { String cardTitle = "More events on this day in history"; ArrayList<String> events = (ArrayList<String>) session.getAttribute(SESSION_TEXT); int index = (Integer) session.getAttribute(SESSION_INDEX); String speechOutput = ""; String cardOutput = ""; if (events == null) { speechOutput = "With History Buff, you can get historical events for any day of the year." + " For example, you could say today, or August thirtieth." + " Now, which day do you want?"; } else if (index >= events.size()) { speechOutput = "There are no more events for this date. Try another date by saying, " + " get events for august thirtieth."; } else { StringBuilder speechOutputBuilder = new StringBuilder(); StringBuilder cardOutputBuilder = new StringBuilder(); for (int i = 0; i < PAGINATION_SIZE && index < events.size(); i++) { speechOutputBuilder.append("<p>"); speechOutputBuilder.append(events.get(index)); speechOutputBuilder.append("</p> "); cardOutputBuilder.append(events.get(index)); cardOutputBuilder.append(" "); index++; } if (index < events.size()) { speechOutputBuilder.append(" Wanna go deeper in history?"); cardOutputBuilder.append(" Wanna go deeper in history?"); } session.setAttribute(SESSION_INDEX, index); speechOutput = speechOutputBuilder.toString(); cardOutput = cardOutputBuilder.toString(); } String repromptText = "Do you want to know more about what happened on this date?"; // Create the Simple card content. SimpleCard card = new SimpleCard(); card.setTitle(cardTitle); card.setContent(cardOutput.toString()); SpeechletResponse response = newAskResponse("<speak>" + speechOutput + "</speak>", true, repromptText, false); response.setCard(card); return response; } /** * Download JSON-formatted list of events from Wikipedia, for a defined day/date, and return a * String array of the events, with each event representing an element in the array. * * @param month * the month to get events for, example: April * @param date * the date to get events for, example: 7 * @return String array of events for that date, 1 event per element of the array */ private ArrayList<String> getJsonEventsFromWikipedia(String month, String date) { InputStreamReader inputStream = null; BufferedReader bufferedReader = null; String text = ""; try { String line; URL url = new URL(URL_PREFIX + month + "_" + date); inputStream = new InputStreamReader(url.openStream(), Charset.forName("US-ASCII")); bufferedReader = new BufferedReader(inputStream); StringBuilder builder = new StringBuilder(); while ((line = bufferedReader.readLine()) != null) { builder.append(line); } text = builder.toString(); } catch (IOException e) { // reset text variable to a blank string text = ""; } finally { IOUtils.closeQuietly(inputStream); IOUtils.closeQuietly(bufferedReader); } return parseJson(text); } /** * Parse JSON-formatted list of events/births/deaths from Wikipedia, extract list of events and * split the events into a String array of individual events. Run Regex matchers to make the * list pretty by adding a comma after the year to add a pause, and by removing a unicode char. * * @param text * the JSON formatted list of events/births/deaths for a certain date * @return String array of events for that date, 1 event per element of the array */ private ArrayList<String> parseJson(String text) { // sizeOf (\nEvents\n) is 10 text = text.substring(text.indexOf("\\nEvents\\n") + SIZE_OF_EVENTS, text.indexOf("\\n\\n\\nBirths")); ArrayList<String> events = new ArrayList<String>(); if (text.isEmpty()) { return events; } int startIndex = 0, endIndex = 0; while (endIndex != -1) { endIndex = text.indexOf("\\n", startIndex + DELIMITER_SIZE); String eventText = (endIndex == -1 ? text.substring(startIndex) : text.substring(startIndex, endIndex)); // replace dashes returned in text from Wikipedia's API Pattern pattern = Pattern.compile("\\\\u2013\\s*"); Matcher matcher = pattern.matcher(eventText); eventText = matcher.replaceAll(""); // add comma after year so Alexa pauses before continuing with the sentence pattern = Pattern.compile("(^\\d+)"); matcher = pattern.matcher(eventText); if (matcher.find()) { eventText = matcher.replaceFirst(matcher.group(1) + ","); } eventText = "In " + eventText; startIndex = endIndex + 2; events.add(eventText); } Collections.reverse(events); return events; } /** * Wrapper for creating the Ask response from the input strings. * * @param stringOutput * the output to be spoken * @param isOutputSsml * whether the output text is of type SSML * @param repromptText * the reprompt for if the user doesn't reply or is misunderstood. * @param isRepromptSsml * whether the reprompt text is of type SSML * @return SpeechletResponse the speechlet response */ private SpeechletResponse newAskResponse(String stringOutput, boolean isOutputSsml, String repromptText, boolean isRepromptSsml) { OutputSpeech outputSpeech, repromptOutputSpeech; if (isOutputSsml) { outputSpeech = new SsmlOutputSpeech(); ((SsmlOutputSpeech) outputSpeech).setSsml(stringOutput); } else { outputSpeech = new PlainTextOutputSpeech(); ((PlainTextOutputSpeech) outputSpeech).setText(stringOutput); } if (isRepromptSsml) { repromptOutputSpeech = new SsmlOutputSpeech(); ((SsmlOutputSpeech) repromptOutputSpeech).setSsml(repromptText); } else { repromptOutputSpeech = new PlainTextOutputSpeech(); ((PlainTextOutputSpeech) repromptOutputSpeech).setText(repromptText); } Reprompt reprompt = new Reprompt(); reprompt.setOutputSpeech(repromptOutputSpeech); return SpeechletResponse.newAskResponse(outputSpeech, reprompt); } }