com.kissmetrics.sdk.VerificationImpl.java Source code

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Here is the source code for com.kissmetrics.sdk.VerificationImpl.java

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//
// KISSmetricsSDK
//
// Copyright 2014 KISSmetrics
//
// 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.

package com.kissmetrics.sdk;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import org.json.JSONObject;

import android.os.Build;
import android.util.Log;

/**
 * VerificationImpl
 * 
 * Handles HttpURLConnections for KISSmetrics verification queries. 
 * 
 */
class VerificationImpl {

    private static final Integer CONNECTION_TIMEOUT = 20;
    private final String TRK_URL = "https://et.kissmetrics.com/m/trk";

    HttpURLConnection connection;

    /**
     * Opens a connection from a URL.
     * Allows for injection of mock HttpURLConnection via method override.
     * 
     * @param url  Verification query URL
     * @return HttpURLConnection  from the URL
     * @throws IOException
     */
    protected HttpURLConnection createHttpURLConnection(URL url) throws IOException {
        return (HttpURLConnection) url.openConnection();
    }

    /**
     * Makes a request to the provided verification urlString.
     * Handles the response and notifies the provided VerificationDelgate on completion.
     * 
     * @param productKey  KISSmetrics product key
     * @param installUuid  Random identifier for this app install
     * @param delegate  VerificationDelegate instance for completion callbacks.
     */
    public void verifyTracking(String productKey, String installUuid, VerificationDelegate delegate) {

        synchronized (this) {

            Log.v("KISSmetricsAPI", "verifyTracking");

            URL url = null;
            connection = null;

            long currentTime = System.currentTimeMillis();

            boolean success = false;
            long expirationDate = 0;
            boolean doTrack = true; // We should always track by default. But we may not always send.
            String baseUrl = "";

            String urlString = String.format("%s?product_key=%s&install_uuid=%s", TRK_URL, productKey, installUuid);

            try {
                url = new URL(urlString);
                connection = createHttpURLConnection(url);
                connection.setUseCaches(true); // !!!: Set cache location. ???:Override expiration
                connection.setRequestMethod("GET");
                connection.setConnectTimeout(CONNECTION_TIMEOUT * 1000);
                connection.setRequestProperty("User-Agent", "KISSmetrics-Android/2.0.3");

                // addressing java.io.EOFException
                if (Build.VERSION.SDK != null && Build.VERSION.SDK_INT > 13) {
                    connection.setRequestProperty("Connection", "close");
                }

                // TODO: Apply any easily obtainable device/OS info
                //setRequestProperty("User-Agent", "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9.2.2) Gecko/20100316 Firefox/3.6.2");

                connection.connect();

                int responseCode = connection.getResponseCode();
                expirationDate = connection.getHeaderFieldDate("Expires", currentTime);

                // Parse response for success
                if (responseCode == 200 || responseCode == 304) {

                    success = true;

                    BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                    StringBuilder sb = new StringBuilder();
                    String line;
                    while ((line = br.readLine()) != null) {
                        sb.append(line + "\n");
                    }
                    br.close();

                    // Expected JSON payload = { "reason": "PRODUCT_SAMPLING", "tracking": false, "tracking_endpoint": "trk.kissmetrics.com"}
                    String jsonString = sb.toString();
                    JSONObject jsonObject = new JSONObject(jsonString);
                    doTrack = jsonObject.getBoolean("tracking");
                    baseUrl = "https://" + jsonObject.getString("tracking_endpoint");
                }

                // ELSE

                // We're getting an unexpected response. KM may be down. Since
                // we can't be sure, we send the default success of false and 
                // doTrack of true.

                // We want to continue to track as we do not want to lose data
                // over this. It will however not be sent or deleted until we 
                // have a confirmed successful instruction to track or not.
            } catch (Exception e) {
                // The KISSmetrics SDK should not cause a customer's app to crash.
                // Log a warning and continue.
                Log.w("KISSmetricsAPI", "Verification experienced an Exception: " + e);
            } finally {

                if (connection != null) {
                    connection.disconnect();
                    connection = null;
                }

                // Callback to delegate
                if (delegate != null) {
                    delegate.verificationComplete(success, doTrack, baseUrl, expirationDate);
                } else {
                    Log.w("KISSmetricsAPI", "Verification delegate not available");
                }
            }
        }
    }
}