org.transdroid.search.barcode.GoogleWebSearchBarcodeResolver.java Source code

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Here is the source code for org.transdroid.search.barcode.GoogleWebSearchBarcodeResolver.java

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/*
 *   This file is part of Transdroid <http://www.transdroid.org>
 *   
 *   Transdroid is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *   
 *   Transdroid is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *   
 *   You should have received a copy of the GNU General Public License
 *   along with Transdroid.  If not, see <http://www.gnu.org/licenses/>.
 *   
 */
package org.transdroid.search.barcode;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.transdroid.daemon.util.HttpHelper;
import org.transdroid.util.TLog;

import android.os.AsyncTask;

public abstract class GoogleWebSearchBarcodeResolver extends AsyncTask<String, Void, String> {

    private static final String LOG_NAME = "Transdroid GoogleWebSearchBarcodeResolver";
    public static final String apiUrl = "http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=%s";

    @Override
    protected String doInBackground(String... params) {

        if (params.length < 1) {
            return null;
        }

        try {
            // We use the Google AJAX Search API to get a JSON-formatted list of web search results
            String callUrl = apiUrl.replace("%s", params[0]);
            TLog.d(LOG_NAME, "Getting web results at " + callUrl);
            DefaultHttpClient httpclient = new DefaultHttpClient();
            HttpGet httpget = new HttpGet(callUrl);
            HttpResponse response = httpclient.execute(httpget);
            InputStream instream = response.getEntity().getContent();
            String result = HttpHelper.ConvertStreamToString(instream);
            JSONArray results = new JSONObject(result).getJSONObject("responseData").getJSONArray("results");

            // We will combine and filter multiple results, if there are any
            TLog.d(LOG_NAME, "Google returned " + results.length() + " results");
            if (results.length() < 1) {
                return null;
            }
            return stripGarbage(results, params[0]);
        } catch (Exception e) {
            TLog.d(LOG_NAME, "Error retrieving barcode: " + e.toString());
            return null;
        }

    }

    @Override
    protected void onPostExecute(String result) {
        onBarcodeLookupComplete(result);
    }

    protected abstract void onBarcodeLookupComplete(String result);

    private static String stripGarbage(JSONArray results, String barcode) throws JSONException {

        String good = " abcdefghijklmnopqrstuvwxyz";
        final int MAX_TITLE_CONSIDER = 4;
        final int MAX_MISSING = 1;
        final int MIN_TITLE_CONSIDER = 2;

        // First gather the titles for the first MAX_TITLE_CONSIDER results
        List<String> titles = new ArrayList<String>();
        for (int i = 0; i < results.length() && i < MAX_TITLE_CONSIDER; i++) {

            String title = results.getJSONObject(i).getString("titleNoFormatting");

            // Make string lowercase first
            title = title.toLowerCase();

            // Remove the barcode number if it's there
            title = title.replace(barcode, "");

            // Remove unwanted words and HTML special chars
            for (String rem : new String[] { "dvd", "blu-ray", "bluray", "&amp;", "&quot;", "&apos;", "&lt;",
                    "&gt;" }) {
                title = title.replace(rem, "");
            }

            // Remove all non-alphanumeric (and space) characters
            String result = "";
            for (int j = 0; j < title.length(); j++) {
                if (good.indexOf(title.charAt(j)) >= 0)
                    result += title.charAt(j);
            }

            // Remove double spaces
            while (result.contains("  ")) {
                result = result.replace("  ", " ");
            }

            titles.add(result);

        }

        // Only retain the words that are missing in at most one of the search result titles
        List<String> allWords = new ArrayList<String>();
        for (String title : titles) {
            for (String word : Arrays.asList(title.split(" "))) {
                if (!allWords.contains(word)) {
                    allWords.add(word);
                }
            }
        }
        List<String> remainingWords = new ArrayList<String>();
        int allowMissing = Math.min(MAX_MISSING, Math.max(titles.size() - MIN_TITLE_CONSIDER, 0));
        for (String word : allWords) {

            int missing = 0;
            for (String title : titles) {
                if (!title.contains(word)) {
                    // The word is not contained in this result title
                    missing++;
                    if (missing > allowMissing) {
                        // Already misssing more than once, no need to look further
                        break;
                    }
                }
            }
            if (missing <= allowMissing) {
                // The word was only missing at most once, so we keep it
                remainingWords.add(word);
            }
        }

        // Now the query is the concatenation of the words remaining; with spaces in between
        String query = "";
        for (String word : remainingWords) {
            query += " " + word;
        }
        return query.length() > 0 ? query.substring(1) : null;

    }

}