Exemple #1
0
 private void appendTo(StringBuilder aText, Object aField, String aAppend) {
   if (Util.textHasContent(Util.format(aField))) {
     aText.append(Util.format(aField));
   } else {
     aText.append(NULL);
   }
   aText.append(aAppend);
 }
Exemple #2
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 private static void parseLine(String aLine) throws InvalidInputException {
   Scanner scanner = new Scanner(aLine);
   // note how the quoting is needed here, since '|' is a special character in
   // regular expressions :
   scanner.useDelimiter(Pattern.quote(DELIMITER));
   scanner.useLocale(Locale.US);
   if (scanner.hasNext()) {
     String title = scanner.next();
     Date viewed = Util.parseDate(maybeNull(scanner.next()), "Date Viewed");
     BigDecimal rating = Util.parseBigDecimal(maybeNull(scanner.next()), "Rating");
     String comment = maybeNull(scanner.next());
     Movie movie = new Movie(nextId().toString(), title, viewed, rating, comment);
     fTable.put(movie.getId(), movie);
   }
   scanner.close();
 }
Exemple #3
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 private static void readInMovieFileUponStartup() {
   Path moviesPath = Paths.get(getMovieFileName());
   fLogger.fine("Reading movies from :" + moviesPath);
   String line = "";
   try (Scanner scanner = new Scanner(moviesPath, ENCODING.name())) {
     while (scanner.hasNextLine()) {
       line = scanner.nextLine();
       if (Util.textHasContent(line)) {
         parseLine(line);
       }
     }
   } catch (FileNotFoundException ex) {
     fLogger.config("Movies file not present. Will be created when the app closes.");
   } catch (InvalidInputException ex) {
     fLogger.severe("Movies file: date-viewed field not in expected format: " + line);
   } catch (NoSuchElementException ex) {
     fLogger.severe("Movies file: Not in expected format: " + line);
   } catch (IOException ex) {
     fLogger.severe("Unable to access the movies file.");
   }
 }
Exemple #4
0
/**
 * Data Access Object (DAO) for {@link Movie} objects.
 *
 * <p>Implements persistence for movie information. This class uses a simple text file called
 * <tt>movie_list_for_&lt;<em>user name</em>&gt;.txt</tt>, stored locally, in the application's home
 * directory. Each logged in user gets their own list. Each logged in user can see their own list,
 * but they cannot see anyone else's list.
 *
 * <p>The format of the file is specific to this application. The file should not be edited directly
 * by an end user, in case the format is violated.
 *
 * <p>Upon startup, all records in the data-store are read into memory. Edits are performed
 * initially only in memory. When the application shuts down, then the updated data store is written
 * back to the disk, for use during the next launch of the application.
 */
public final class MovieDAO {

  /**
   * Save all data to a text file. Must be called explicitly when the app shuts down, in order to
   * save all edits.
   */
  public void shutdown() {
    fLogger.fine("Saving all movie records to file.");
    String fileContents = buildFileContents();
    writeStringToFile(fileContents);
  }

  /** Add a new {@link Movie}. */
  void add(Movie aMovie) {
    String id = nextId();
    aMovie.setId(id.toString());
    fTable.put(id, aMovie);
  }

  /** Change an existing {@link Movie}. */
  void change(Movie aMovie) {
    fTable.put(aMovie.getId(), aMovie);
  }

  /**
   * List all {@link Movie}s. Order is the natural order of the {@link Movie} class (descending
   * date, then title).
   */
  List<Movie> list() {
    List<Movie> result = new ArrayList<>(fTable.values());
    Collections.sort(result);
    return result;
  }

  /** Delete an existing {@link Movie}, given the movie id. */
  void delete(String aMovieId) {
    fTable.remove(aMovieId);
  }

  // PRIVATE
  private static final Map<String, Movie> fTable = new LinkedHashMap<>();
  private static int fNextId = 0;
  private static final String MOVIES_FILE_NAME = "movie_list_for_";
  private static final String DELIMITER = "|";
  private static final String NULL = "NULL";
  private static final Logger fLogger = Util.getLogger(MovieDAO.class);
  private static final Charset ENCODING = StandardCharsets.UTF_8;

  static {
    readInMovieFileUponStartup();
    fLogger.config("Number of movies read in from file: " + fTable.size());
  }

  private static void readInMovieFileUponStartup() {
    Path moviesPath = Paths.get(getMovieFileName());
    fLogger.fine("Reading movies from :" + moviesPath);
    String line = "";
    try (Scanner scanner = new Scanner(moviesPath, ENCODING.name())) {
      while (scanner.hasNextLine()) {
        line = scanner.nextLine();
        if (Util.textHasContent(line)) {
          parseLine(line);
        }
      }
    } catch (FileNotFoundException ex) {
      fLogger.config("Movies file not present. Will be created when the app closes.");
    } catch (InvalidInputException ex) {
      fLogger.severe("Movies file: date-viewed field not in expected format: " + line);
    } catch (NoSuchElementException ex) {
      fLogger.severe("Movies file: Not in expected format: " + line);
    } catch (IOException ex) {
      fLogger.severe("Unable to access the movies file.");
    }
  }

  private static void parseLine(String aLine) throws InvalidInputException {
    Scanner scanner = new Scanner(aLine);
    // note how the quoting is needed here, since '|' is a special character in
    // regular expressions :
    scanner.useDelimiter(Pattern.quote(DELIMITER));
    scanner.useLocale(Locale.US);
    if (scanner.hasNext()) {
      String title = scanner.next();
      Date viewed = Util.parseDate(maybeNull(scanner.next()), "Date Viewed");
      BigDecimal rating = Util.parseBigDecimal(maybeNull(scanner.next()), "Rating");
      String comment = maybeNull(scanner.next());
      Movie movie = new Movie(nextId().toString(), title, viewed, rating, comment);
      fTable.put(movie.getId(), movie);
    }
    scanner.close();
  }

  private static String nextId() {
    ++fNextId;
    return String.valueOf(fNextId);
  }

  private void appendTo(StringBuilder aText, Object aField, String aAppend) {
    if (Util.textHasContent(Util.format(aField))) {
      aText.append(Util.format(aField));
    } else {
      aText.append(NULL);
    }
    aText.append(aAppend);
  }

  private static String maybeNull(String aText) {
    return NULL.equals(aText) ? null : aText;
  }

  private static String getMovieFileName() {
    return MOVIES_FILE_NAME
        + MainWindow.getInstance().getUserName().toLowerCase(Locale.ENGLISH)
        + ".txt";
  }

  /** Create a string, holding all movie records. */
  private String buildFileContents() {
    String NEW_LINE = System.getProperty("line.separator");
    StringBuilder result = new StringBuilder();
    for (Movie movie : fTable.values()) {
      appendTo(result, movie.getTitle(), DELIMITER);
      appendTo(result, movie.getDateViewed(), DELIMITER);
      appendTo(result, movie.getRating(), DELIMITER);
      appendTo(result, movie.getComment(), NEW_LINE);
    }
    return result.toString();
  }

  /** Write string containing all movie records to a file - overwrite the whole file. */
  private void writeStringToFile(String aFileContents) {
    Path moviesPath = Paths.get(getMovieFileName());
    fLogger.fine("Writing movies to: " + moviesPath);
    try (BufferedWriter writer = Files.newBufferedWriter(moviesPath, ENCODING)) {
      writer.write(aFileContents);
    } catch (FileNotFoundException ex) {
      fLogger.severe("Cannot find movies text file.");
    } catch (IOException ex) {
      fLogger.severe("Problem while saving movies text file.");
    }
  }
}