ai.api.twilio.BaseTwilioServlet.java Source code

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Here is the source code for ai.api.twilio.BaseTwilioServlet.java

Source

package ai.api.twilio;

/***********************************************************************************************************************
 *
 * API.AI Twilio Helper Libs
 * =================================================
 *
 * Copyright (C) 2015 by Speaktoit, Inc / Api.ai (https://speaktoit.com)
 * https://api.ai
 *
 ***********************************************************************************************************************
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License 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.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import javax.servlet.http.HttpServlet;

import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.RequestBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Strings;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.annotations.Expose;

/**
 * BaseTwilioServlet. Encapsulates methods to communicate with api.ai.
 */
public class BaseTwilioServlet extends HttpServlet {
    private static final long serialVersionUID = -8510776154233631616L;
    private static final CloseableHttpClient POOLING_HTTP_CLIENT;

    private static final Logger LOGGER = LoggerFactory.getLogger(BaseTwilioServlet.class);

    protected Gson gson = new GsonBuilder().create();

    static {
        PoolingHttpClientConnectionManager POOLING_HTTP_CONN_MANAGER = new PoolingHttpClientConnectionManager();
        POOLING_HTTP_CONN_MANAGER.setDefaultMaxPerRoute(20);
        POOLING_HTTP_CLIENT = HttpClients.custom()
                .setDefaultRequestConfig(RequestConfig.custom().setStaleConnectionCheckEnabled(true).build())
                .setConnectionManager(POOLING_HTTP_CONN_MANAGER).build();
    }

    /**
     * Send request to api.ai
     * 
     * @param query
     * @param parameters
     *            - parameters received from www.twilio.com
     * @return response from api.ai
     */
    protected String sendRequestToApiAi(String query, Map<String, String[]> parameters) {
        HttpResponse response = null;
        try {
            StringEntity input = new StringEntity(createApiRequest(query, parameters),
                    ContentType.APPLICATION_JSON);

            response = POOLING_HTTP_CLIENT.execute(RequestBuilder.post()
                    .setUri(TwilioProperties.INSTANCE.getApiUrl())
                    .addHeader("Authorization", "Bearer " + TwilioProperties.INSTANCE.getApiAccessToken())
                    .addHeader("Accept", ContentType.APPLICATION_JSON.getMimeType()).setEntity(input).build());

            if (response.getStatusLine().getStatusCode() / 100 != 2) {
                return "Error: " + response.getStatusLine();
            }
            BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));

            StringBuilder resultBuilder = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                resultBuilder.append(line);
            }

            ApiResponse resultResp = gson.fromJson(resultBuilder.toString(), ApiResponse.class);
            if (Strings.isNullOrEmpty(Optional.ofNullable(resultResp.result).map(r -> r.fulfillment)
                    .map(f -> f.speech).orElse(null))) {
                return "Action: " + Optional.ofNullable(resultResp.result).map(r -> r.action).orElse("none") + "\n"
                        + gson.toJson(Optional.ofNullable(resultResp.result).map(r -> r.parameters)
                                .orElse(Collections.emptyMap()));
            }
            return resultResp.result.fulfillment.speech;
        } catch (IOException e) {
            LOGGER.error(e.getMessage());
            return "Error: " + e.getMessage();
        } finally {
            if (response != null) {
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (IOException e) {
                    // Ignore
                }
            }
        }
    }

    /**
     * Create request to api.ai
     * 
     * @param query
     * @param parameters
     *            - parameters received from www.twilio.com
     * @return request to api.ai
     */
    protected String createApiRequest(String query, Map<String, String[]> parameters) {
        ApiRequest req = new ApiRequest();
        req.lang = "en";
        req.sessionId = Optional.ofNullable(parameters.get("From")).map(p -> p[0]).orElse("defaultSession");
        req.timezone = TwilioProperties.INSTANCE.getTimezone();
        req.query = query;

        return gson.toJson(req);
    }

    public static class ApiRequest {
        public String query;
        public String lang;
        public String timezone;
        public String sessionId;

        public List<ApiContext> contexts;
    }

    public static class ApiContext {
        public String name;
        public Map<String, String> parameters;
    }

    public static class ApiResponse {
        @Expose
        public Result result;
    }

    public static class Result {
        public String source;
        public String resolvedQuery;
        public String action;
        Map<String, Object> parameters;
        public Map<String, Object> metadata = new HashMap<>();
        public Fulfillment fulfillment;
    }

    public static class Fulfillment {
        public String speech;
        public String source;

        public Fulfillment() {
        };

        public Fulfillment(String speech, Object source) {
            this.speech = speech;
            this.source = source instanceof String ? (String) source : null;
        };
    }
}