se.chalmers.watchme.net.IMDBHandler.java Source code

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Here is the source code for se.chalmers.watchme.net.IMDBHandler.java

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/**
 *   IMDBHandler.java
 *
 *   Class responsible for making requests to the IMDb API.
 *
 *   @author Johan
 *   @copyright (c) 2012 Johan Brook, Robin Andersson, Lisa Stenberg, Mattias Henriksson
 *   @license MIT
 */

package se.chalmers.watchme.net;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class IMDBHandler implements MovieSource {

    /** The TMDb API url */
    public static final String API_URL = "http://api.themoviedb.org/2.1/";

    /** The API movie search method */
    private static final String MOVIE_SEARCH = "Movie.search/";
    /** The API movie info method */
    private static final String MOVIE_INFO = "Movie.getInfo/";
    /** The IMDb lookup method */
    private static final String IMDB_INFO = "Movie.imdbLookup/";
    /** Specify language */
    private static final String LANGUAGE = "en/";
    /** Return format */
    private static final String JSON_FORMAT = "json/";

    /** The TMDb API key */
    private static final String API_KEY = "6af2e4697c90e9c6e4a8f2434eb3c5fe";

    // Initialize the HTTP handler
    private HttpRetriever http = new HttpRetriever();

    /**
     * Build a URL for searching the API from a query.
     * 
     * <p>
     * <strong>Format:</strong>
     * </p>
     * 
     * <pre>
     * <code>http://api.themoviedb.org/2.1/Movie.search/en/json/APIKEY/query</code>
     * </pre>
     * 
     * @param query
     *            The query, i.e. a movie title
     * @return A String with the complete request url
     */
    private String buildURL(String query, String method) {
        StringBuilder s = new StringBuilder();

        try {
            s.append(API_URL).append(method).append(LANGUAGE).append(JSON_FORMAT).append(API_KEY).append("/")
                    .append(URLEncoder.encode(query, "UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        return s.toString();
    }

    /**
     * Searching the API for a movie.
     * 
     * @param title
     *            The movie title
     * @return A JSONArray with the movies as JSONObjects on success. Otherwise
     *         null
     */
    public JSONArray getMoviesByTitle(String title) {
        final String url = this.buildURL(title, MOVIE_SEARCH);
        String response = this.getResponse(url);

        /*
         * Since the API service doesn't use sane HTTP status codes for things
         * such as non-existing movies, we have to compare to a static string ..
         */
        if (response == null || response.indexOf("Nothing found") != -1) {
            return null;
        }

        JSONArray movies = null;

        try {
            movies = new JSONArray(response);
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return movies;
    }

    /**
     * Get a movie from the API movie id
     * 
     * @param id
     *            The API movie id. Get from either getMovieByIMDBID or
     *            getMoviesByTitle
     * @return A JSONObject representing the movie. If nothing was found, it
     *         returns null
     */
    public JSONObject getMovieById(int id) {
        final String url = this.buildURL(String.valueOf(id), MOVIE_INFO);
        String response = this.getResponse(url);

        return (response == null) ? null : parseStringToJSON(response);
    }

    /**
     * Get a movie from IMDb as a JSON object.
     * 
     * @param id
     *            The IMDB ID
     * @return A JSON object representing the movie. If no movie was found, it
     *         returns null
     */
    public JSONObject getMovieByIMDBID(String id) {
        final String url = this.buildURL(id, IMDB_INFO);
        String response = this.getResponse(url);

        return (response == null) ? null : parseStringToJSON(response);
    }

    /**
     * Helper function to create a new JSONObject from a string.
     * 
     * <p>
     * Note that this function checks if the input string is a JSON array, e.g.
     * checks for square brackets in the beginning and end. If the string is an
     * array with a single JSON object, the object is parsed.
     * </p>
     * 
     * @param s
     *            The input string
     * @return A JSONObject from the string. Returns null if an error occurred
     *         while parsing the string
     */
    public static JSONObject parseStringToJSON(String s) {
        JSONObject json = null;

        try {
            if (s.charAt(0) == '[' && s.charAt(s.length() - 1) == ']') {
                JSONArray ar = new JSONArray(s);
                json = ar.getJSONObject(0);
            } else {
                json = new JSONObject(s);
            }

        } catch (JSONException e) {
            System.err.println("Error while parsing JSONObject");
            System.err.println(e.getMessage());
            e.printStackTrace();
        }

        return json;
    }

    /**
     * Helper method to get a String response from an URL.
     * 
     * <p>
     * Catches eventual exceptions.
     * </p>
     * 
     * @param url
     *            The URL
     * @return A String response. Returns null if something went wrong.
     */
    private String getResponse(String url) {
        String response = null;

        try {
            response = this.http.get(url);
        } catch (IOException e) {
            System.err.print("Error fetching " + url + ": ");
            System.err.println(e.getMessage());
        } catch (NoEntityException e) {
            System.err.println(e.getMessage());
        }

        return response;
    }
}