src/main/java/net/pterodactylus/sone/web/SearchPage.java

   1 /*
   2  * Sone - SearchPage.java - Copyright © 2010–2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sone.web;
  19
  20 import static com.google.common.base.Optional.fromNullable;
  21 import static com.google.common.primitives.Ints.tryParse;
  22 import static java.util.logging.Logger.getLogger;
  23
  24 import java.util.ArrayList;
  25 import java.util.Collection;
  26 import java.util.Collections;
  27 import java.util.Comparator;
  28 import java.util.HashSet;
  29 import java.util.List;
  30 import java.util.Set;
  31 import java.util.concurrent.TimeUnit;
  32 import java.util.logging.Level;
  33 import java.util.logging.Logger;
  34
  35 import net.pterodactylus.sone.data.Post;
  36 import net.pterodactylus.sone.data.PostReply;
  37 import net.pterodactylus.sone.data.Profile;
  38 import net.pterodactylus.sone.data.Profile.Field;
  39 import net.pterodactylus.sone.data.Reply;
  40 import net.pterodactylus.sone.data.Sone;
  41 import net.pterodactylus.sone.web.page.FreenetRequest;
  42 import net.pterodactylus.util.collection.Pagination;
  43 import net.pterodactylus.util.template.Template;
  44 import net.pterodactylus.util.template.TemplateContext;
  45 import net.pterodactylus.util.text.StringEscaper;
  46 import net.pterodactylus.util.text.TextException;
  47
  48 import com.google.common.base.Function;
  49 import com.google.common.base.Optional;
  50 import com.google.common.base.Predicate;
  51 import com.google.common.cache.CacheBuilder;
  52 import com.google.common.cache.CacheLoader;
  53 import com.google.common.cache.LoadingCache;
  54 import com.google.common.collect.Collections2;
  55 import com.google.common.collect.FluentIterable;
  56 import com.google.common.collect.Ordering;
  57
  58 /**
  59  * This page lets the user search for posts and replies that contain certain
  60  * words.
  61  *
  62  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  63  */
  64 public class SearchPage extends SoneTemplatePage {
  65
  66         /** The logger. */
  67         private static final Logger logger = getLogger("Sone.Web.Search");
  68
  69         /** Short-term cache. */
  70         private final LoadingCache<List<Phrase>, Set<Hit<Post>>> hitCache = CacheBuilder.newBuilder().expireAfterWrite(5, TimeUnit.MINUTES).build(new CacheLoader<List<Phrase>, Set<Hit<Post>>>() {
  71
  72                 @Override
  73                 @SuppressWarnings("synthetic-access")
  74                 public Set<Hit<Post>> load(List<Phrase> phrases) {
  75                         Set<Post> posts = new HashSet<Post>();
  76                         for (Sone sone : webInterface.getCore().getSones()) {
  77                                 posts.addAll(sone.getPosts());
  78                         }
  79                         return getHits(Collections2.filter(posts, Post.FUTURE_POSTS_FILTER), phrases, new PostStringGenerator());
  80                 }
  81         });
  82
  83         /**
  84          * Creates a new search page.
  85          *
  86          * @param template
  87          *            The template to render
  88          * @param webInterface
  89          *            The Sone web interface
  90          */
  91         public SearchPage(Template template, WebInterface webInterface) {
  92                 super("search.html", template, "Page.Search.Title", webInterface);
  93         }
  94
  95         //
  96         // SONETEMPLATEPAGE METHODS
  97         //
  98
  99         /**
 100          * {@inheritDoc}
 101          */
 102         @Override
 103         @SuppressWarnings("synthetic-access")
 104         protected void processTemplate(FreenetRequest request, TemplateContext templateContext) throws RedirectException {
 105                 super.processTemplate(request, templateContext);
 106                 String query = request.getHttpRequest().getParam("query").trim();
 107                 if (query.length() == 0) {
 108                         throw new RedirectException("index.html");
 109                 }
 110
 111                 List<Phrase> phrases = parseSearchPhrases(query);
 112                 if (phrases.isEmpty()) {
 113                         throw new RedirectException("index.html");
 114                 }
 115
 116                 /* check for a couple of shortcuts. */
 117                 if (phrases.size() == 1) {
 118                         String phrase = phrases.get(0).getPhrase();
 119
 120                         /* is it a Sone ID? */
 121                         redirectIfNotNull(getSoneId(phrase), "viewSone.html?sone=");
 122
 123                         /* is it a post ID? */
 124                         redirectIfNotNull(getPostId(phrase), "viewPost.html?post=");
 125
 126                         /* is it a reply ID? show the post. */
 127                         redirectIfNotNull(getReplyPostId(phrase), "viewPost.html?post=");
 128
 129                         /* is it an album ID? */
 130                         redirectIfNotNull(getAlbumId(phrase), "imageBrowser.html?album=");
 131
 132                         /* is it an image ID? */
 133                         redirectIfNotNull(getImageId(phrase), "imageBrowser.html?image=");
 134                 }
 135
 136                 Collection<Sone> sones = webInterface.getCore().getSones();
 137                 Collection<Hit<Sone>> soneHits = getHits(sones, phrases, SoneStringGenerator.COMPLETE_GENERATOR);
 138
 139                 Collection<Hit<Post>> postHits = hitCache.getUnchecked(phrases);
 140
 141                 /* now filter. */
 142                 soneHits = Collections2.filter(soneHits, Hit.POSITIVE_FILTER);
 143                 postHits = Collections2.filter(postHits, Hit.POSITIVE_FILTER);
 144
 145                 /* now sort. */
 146                 List<Hit<Sone>> sortedSoneHits = Ordering.from(Hit.DESCENDING_COMPARATOR).sortedCopy(soneHits);
 147                 List<Hit<Post>> sortedPostHits = Ordering.from(Hit.DESCENDING_COMPARATOR).sortedCopy(postHits);
 148
 149                 /* extract Sones and posts. */
 150                 List<Sone> resultSones = FluentIterable.from(sortedSoneHits).transform(new HitMapper<Sone>()).toList();
 151                 List<Post> resultPosts = FluentIterable.from(sortedPostHits).transform(new HitMapper<Post>()).toList();
 152
 153                 /* pagination. */
 154                 Pagination<Sone> sonePagination = new Pagination<Sone>(resultSones, webInterface.getCore().getPreferences().getPostsPerPage()).setPage(fromNullable(tryParse(request.getHttpRequest().getParam("sonePage"))).or(0));
 155                 Pagination<Post> postPagination = new Pagination<Post>(resultPosts, webInterface.getCore().getPreferences().getPostsPerPage()).setPage(fromNullable(tryParse(request.getHttpRequest().getParam("postPage"))).or(0));
 156
 157                 templateContext.set("sonePagination", sonePagination);
 158                 templateContext.set("soneHits", sonePagination.getItems());
 159                 templateContext.set("postPagination", postPagination);
 160                 templateContext.set("postHits", postPagination.getItems());
 161         }
 162
 163         //
 164         // PRIVATE METHODS
 165         //
 166
 167         /**
 168          * Collects hit information for the given objects. The objects are converted
 169          * to a {@link String} using the given {@link StringGenerator}, and the
 170          * {@link #calculateScore(List, String) calculated score} is stored together
 171          * with the object in a {@link Hit}, and all resulting {@link Hit}s are then
 172          * returned.
 173          *
 174          * @param <T>
 175          *            The type of the objects
 176          * @param objects
 177          *            The objects to search over
 178          * @param phrases
 179          *            The phrases to search for
 180          * @param stringGenerator
 181          *            The string generator for the objects
 182          * @return The hits for the given phrases
 183          */
 184         private static <T> Set<Hit<T>> getHits(Collection<T> objects, List<Phrase> phrases, StringGenerator<T> stringGenerator) {
 185                 Set<Hit<T>> hits = new HashSet<Hit<T>>();
 186                 for (T object : objects) {
 187                         String objectString = stringGenerator.generateString(object);
 188                         double score = calculateScore(phrases, objectString);
 189                         hits.add(new Hit<T>(object, score));
 190                 }
 191                 return hits;
 192         }
 193
 194         /**
 195          * Parses the given query into search phrases. The query is split on
 196          * whitespace while allowing to group words using single or double quotes.
 197          * Isolated phrases starting with a “+” are
 198          * {@link Phrase.Optionality#REQUIRED}, phrases with a “-” are
 199          * {@link Phrase.Optionality#FORBIDDEN}.
 200          *
 201          * @param query
 202          *            The query to parse
 203          * @return The parsed phrases
 204          */
 205         private static List<Phrase> parseSearchPhrases(String query) {
 206                 List<String> parsedPhrases;
 207                 try {
 208                         parsedPhrases = StringEscaper.parseLine(query);
 209                 } catch (TextException te1) {
 210                         /* invalid query. */
 211                         return Collections.emptyList();
 212                 }
 213
 214                 List<Phrase> phrases = new ArrayList<Phrase>();
 215                 for (String phrase : parsedPhrases) {
 216                         if (phrase.startsWith("+")) {
 217                                 if (phrase.length() > 1) {
 218                                         phrases.add(new Phrase(phrase.substring(1), Phrase.Optionality.REQUIRED));
 219                                 } else {
 220                                         phrases.add(new Phrase("+", Phrase.Optionality.OPTIONAL));
 221                                 }
 222                         } else if (phrase.startsWith("-")) {
 223                                 if (phrase.length() > 1) {
 224                                         phrases.add(new Phrase(phrase.substring(1), Phrase.Optionality.FORBIDDEN));
 225                                 } else {
 226                                         phrases.add(new Phrase("-", Phrase.Optionality.OPTIONAL));
 227                                 }
 228                         } else {
 229                                 phrases.add(new Phrase(phrase, Phrase.Optionality.OPTIONAL));
 230                         }
 231                 }
 232                 return phrases;
 233         }
 234
 235         /**
 236          * Calculates the score for the given expression when using the given
 237          * phrases.
 238          *
 239          * @param phrases
 240          *            The phrases to search for
 241          * @param expression
 242          *            The expression to search
 243          * @return The score of the expression
 244          */
 245         private static double calculateScore(List<Phrase> phrases, String expression) {
 246                 logger.log(Level.FINEST, String.format("Calculating Score for “%s”…", expression));
 247                 double optionalHits = 0;
 248                 double requiredHits = 0;
 249                 int forbiddenHits = 0;
 250                 int requiredPhrases = 0;
 251                 for (Phrase phrase : phrases) {
 252                         String phraseString = phrase.getPhrase().toLowerCase();
 253                         if (phrase.getOptionality() == Phrase.Optionality.REQUIRED) {
 254                                 ++requiredPhrases;
 255                         }
 256                         int matches = 0;
 257                         int index = 0;
 258                         double score = 0;
 259                         while (index < expression.length()) {
 260                                 int position = expression.toLowerCase().indexOf(phraseString, index);
 261                                 if (position == -1) {
 262                                         break;
 263                                 }
 264                                 score += Math.pow(1 - position / (double) expression.length(), 2);
 265                                 index = position + phraseString.length();
 266                                 logger.log(Level.FINEST, String.format("Got hit at position %d.", position));
 267                                 ++matches;
 268                         }
 269                         logger.log(Level.FINEST, String.format("Score: %f", score));
 270                         if (matches == 0) {
 271                                 continue;
 272                         }
 273                         if (phrase.getOptionality() == Phrase.Optionality.REQUIRED) {
 274                                 requiredHits += score;
 275                         }
 276                         if (phrase.getOptionality() == Phrase.Optionality.OPTIONAL) {
 277                                 optionalHits += score;
 278                         }
 279                         if (phrase.getOptionality() == Phrase.Optionality.FORBIDDEN) {
 280                                 forbiddenHits += matches;
 281                         }
 282                 }
 283                 return requiredHits * 3 + optionalHits + (requiredHits - requiredPhrases) * 5 - (forbiddenHits * 2);
 284         }
 285
 286         /**
 287          * Throws a
 288          * {@link net.pterodactylus.sone.web.page.FreenetTemplatePage.RedirectException}
 289          * if the given object is not {@code null}, appending the object to the
 290          * given target URL.
 291          *
 292          * @param object
 293          *            The object on which to redirect
 294          * @param target
 295          *            The target of the redirect
 296          * @throws RedirectException
 297          *             if {@code object} is not {@code null}
 298          */
 299         private static void redirectIfNotNull(String object, String target) throws RedirectException {
 300                 if (object != null) {
 301                         throw new RedirectException(target + object);
 302                 }
 303         }
 304
 305         /**
 306          * If the given phrase contains a Sone ID (optionally prefixed by
 307          * “sone://”), returns said Sone ID, otherwise return {@code null}.
 308          *
 309          * @param phrase
 310          *            The phrase that maybe is a Sone ID
 311          * @return The Sone ID, or {@code null}
 312          */
 313         private String getSoneId(String phrase) {
 314                 String soneId = phrase.startsWith("sone://") ? phrase.substring(7) : phrase;
 315                 return (webInterface.getCore().getSone(soneId).isPresent()) ? soneId : null;
 316         }
 317
 318         /**
 319          * If the given phrase contains a post ID (optionally prefixed by
 320          * “post://”), returns said post ID, otherwise return {@code null}.
 321          *
 322          * @param phrase
 323          *            The phrase that maybe is a post ID
 324          * @return The post ID, or {@code null}
 325          */
 326         private String getPostId(String phrase) {
 327                 String postId = phrase.startsWith("post://") ? phrase.substring(7) : phrase;
 328                 return (webInterface.getCore().getPost(postId).isPresent()) ? postId : null;
 329         }
 330
 331         /**
 332          * If the given phrase contains a reply ID (optionally prefixed by
 333          * “reply://”), returns the ID of the post the reply belongs to, otherwise
 334          * return {@code null}.
 335          *
 336          * @param phrase
 337          *            The phrase that maybe is a reply ID
 338          * @return The reply’s post ID, or {@code null}
 339          */
 340         private String getReplyPostId(String phrase) {
 341                 String replyId = phrase.startsWith("reply://") ? phrase.substring(8) : phrase;
 342                 Optional<PostReply> postReply = webInterface.getCore().getPostReply(replyId);
 343                 if (!postReply.isPresent()) {
 344                         return null;
 345                 }
 346                 return postReply.get().getPostId();
 347         }
 348
 349         /**
 350          * If the given phrase contains an album ID (optionally prefixed by
 351          * “album://”), returns said album ID, otherwise return {@code null}.
 352          *
 353          * @param phrase
 354          *            The phrase that maybe is an album ID
 355          * @return The album ID, or {@code null}
 356          */
 357         private String getAlbumId(String phrase) {
 358                 String albumId = phrase.startsWith("album://") ? phrase.substring(8) : phrase;
 359                 return (webInterface.getCore().getAlbum(albumId) != null) ? albumId : null;
 360         }
 361
 362         /**
 363          * If the given phrase contains an image ID (optionally prefixed by
 364          * “image://”), returns said image ID, otherwise return {@code null}.
 365          *
 366          * @param phrase
 367          *            The phrase that maybe is an image ID
 368          * @return The image ID, or {@code null}
 369          */
 370         private String getImageId(String phrase) {
 371                 String imageId = phrase.startsWith("image://") ? phrase.substring(8) : phrase;
 372                 return (webInterface.getCore().getImage(imageId, false) != null) ? imageId : null;
 373         }
 374
 375         /**
 376          * Converts a given object into a {@link String}.
 377          *
 378          * @param <T>
 379          *            The type of the objects
 380          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 381          */
 382         private static interface StringGenerator<T> {
 383
 384                 /**
 385                  * Generates a {@link String} for the given object.
 386                  *
 387                  * @param object
 388                  *            The object to generate the {@link String} for
 389                  * @return The generated {@link String}
 390                  */
 391                 public String generateString(T object);
 392
 393         }
 394
 395         /**
 396          * Generates a {@link String} from a {@link Sone}, concatenating the name of
 397          * the Sone and all {@link Profile} {@link Field} values.
 398          *
 399          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 400          */
 401         private static class SoneStringGenerator implements StringGenerator<Sone> {
 402
 403                 /** A static instance of a complete Sone string generator. */
 404                 public static final SoneStringGenerator COMPLETE_GENERATOR = new SoneStringGenerator(true);
 405
 406                 /**
 407                  * A static instance of a Sone string generator that will only use the
 408                  * name of the Sone.
 409                  */
 410                 public static final SoneStringGenerator NAME_GENERATOR = new SoneStringGenerator(false);
 411
 412                 /** Whether to generate a string from all data of a Sone. */
 413                 private final boolean complete;
 414
 415                 /**
 416                  * Creates a new Sone string generator.
 417                  *
 418                  * @param complete
 419                  *            {@code true} to use the profile’s fields, {@code false} to
 420                  *            not to use the profile‘s fields
 421                  */
 422                 private SoneStringGenerator(boolean complete) {
 423                         this.complete = complete;
 424                 }
 425
 426                 /**
 427                  * {@inheritDoc}
 428                  */
 429                 @Override
 430                 public String generateString(Sone sone) {
 431                         StringBuilder soneString = new StringBuilder();
 432                         soneString.append(sone.getName());
 433                         Profile soneProfile = sone.getProfile();
 434                         if (soneProfile.getFirstName() != null) {
 435                                 soneString.append(' ').append(soneProfile.getFirstName());
 436                         }
 437                         if (soneProfile.getMiddleName() != null) {
 438                                 soneString.append(' ').append(soneProfile.getMiddleName());
 439                         }
 440                         if (soneProfile.getLastName() != null) {
 441                                 soneString.append(' ').append(soneProfile.getLastName());
 442                         }
 443                         if (complete) {
 444                                 for (Field field : soneProfile.getFields()) {
 445                                         soneString.append(' ').append(field.getValue());
 446                                 }
 447                         }
 448                         return soneString.toString();
 449                 }
 450
 451         }
 452
 453         /**
 454          * Generates a {@link String} from a {@link Post}, concatenating the text of
 455          * the post, the text of all {@link Reply}s, and the name of all
 456          * {@link Sone}s that have replied.
 457          *
 458          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 459          */
 460         private class PostStringGenerator implements StringGenerator<Post> {
 461
 462                 /**
 463                  * {@inheritDoc}
 464                  */
 465                 @Override
 466                 public String generateString(Post post) {
 467                         StringBuilder postString = new StringBuilder();
 468                         postString.append(post.getText());
 469                         if (post.getRecipient().isPresent()) {
 470                                 postString.append(' ').append(SoneStringGenerator.NAME_GENERATOR.generateString(post.getRecipient().get()));
 471                         }
 472                         for (PostReply reply : Collections2.filter(webInterface.getCore().getReplies(post.getId()), Reply.FUTURE_REPLY_FILTER)) {
 473                                 postString.append(' ').append(SoneStringGenerator.NAME_GENERATOR.generateString(reply.getSone()));
 474                                 postString.append(' ').append(reply.getText());
 475                         }
 476                         return postString.toString();
 477                 }
 478
 479         }
 480
 481         /**
 482          * A search phrase.
 483          *
 484          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 485          */
 486         private static class Phrase {
 487
 488                 /**
 489                  * The optionality of a search phrase.
 490                  *
 491                  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’
 492                  *         Roden</a>
 493                  */
 494                 public enum Optionality {
 495
 496                         /** The phrase is optional. */
 497                         OPTIONAL,
 498
 499                         /** The phrase is required. */
 500                         REQUIRED,
 501
 502                         /** The phrase is forbidden. */
 503                         FORBIDDEN
 504
 505                 }
 506
 507                 /** The phrase to search for. */
 508                 private final String phrase;
 509
 510                 /** The optionality of the phrase. */
 511                 private final Optionality optionality;
 512
 513                 /**
 514                  * Creates a new phrase.
 515                  *
 516                  * @param phrase
 517                  *            The phrase to search for
 518                  * @param optionality
 519                  *            The optionality of the phrase
 520                  */
 521                 public Phrase(String phrase, Optionality optionality) {
 522                         this.optionality = optionality;
 523                         this.phrase = phrase;
 524                 }
 525
 526                 /**
 527                  * Returns the phrase to search for.
 528                  *
 529                  * @return The phrase to search for
 530                  */
 531                 public String getPhrase() {
 532                         return phrase;
 533                 }
 534
 535                 /**
 536                  * Returns the optionality of the phrase.
 537                  *
 538                  * @return The optionality of the phrase
 539                  */
 540                 public Optionality getOptionality() {
 541                         return optionality;
 542                 }
 543
 544                 //
 545                 // OBJECT METHODS
 546                 //
 547
 548                 /**
 549                  * {@inheritDoc}
 550                  */
 551                 @Override
 552                 public int hashCode() {
 553                         return phrase.hashCode() ^ ((optionality == Optionality.FORBIDDEN) ? (0xaaaaaaaa) : ((optionality == Optionality.REQUIRED) ? 0x55555555 : 0));
 554                 }
 555
 556                 /**
 557                  * {@inheritDoc}
 558                  */
 559                 @Override
 560                 public boolean equals(Object object) {
 561                         if (!(object instanceof Phrase)) {
 562                                 return false;
 563                         }
 564                         Phrase phrase = (Phrase) object;
 565                         return (this.optionality == phrase.optionality) && this.phrase.equals(phrase.phrase);
 566                 }
 567
 568         }
 569
 570         /**
 571          * A hit consists of a searched object and the score it got for the phrases
 572          * of the search.
 573          *
 574          * @see SearchPage#calculateScore(List, String)
 575          * @param <T>
 576          *            The type of the searched object
 577          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 578          */
 579         private static class Hit<T> {
 580
 581                 /** Filter for {@link Hit}s with a score of more than 0. */
 582                 public static final Predicate<Hit<?>> POSITIVE_FILTER = new Predicate<Hit<?>>() {
 583
 584                         @Override
 585                         public boolean apply(Hit<?> hit) {
 586                                 return (hit != null) && (hit.getScore() > 0);
 587                         }
 588
 589                 };
 590
 591                 /** Comparator that sorts {@link Hit}s descending by score. */
 592                 public static final Comparator<Hit<?>> DESCENDING_COMPARATOR = new Comparator<Hit<?>>() {
 593
 594                         @Override
 595                         public int compare(Hit<?> leftHit, Hit<?> rightHit) {
 596                                 return (rightHit.getScore() < leftHit.getScore()) ? -1 : ((rightHit.getScore() > leftHit.getScore()) ? 1 : 0);
 597                         }
 598
 599                 };
 600
 601                 /** The object that was searched. */
 602                 private final T object;
 603
 604                 /** The score of the object. */
 605                 private final double score;
 606
 607                 /**
 608                  * Creates a new hit.
 609                  *
 610                  * @param object
 611                  *            The object that was searched
 612                  * @param score
 613                  *            The score of the object
 614                  */
 615                 public Hit(T object, double score) {
 616                         this.object = object;
 617                         this.score = score;
 618                 }
 619
 620                 /**
 621                  * Returns the object that was searched.
 622                  *
 623                  * @return The object that was searched
 624                  */
 625                 public T getObject() {
 626                         return object;
 627                 }
 628
 629                 /**
 630                  * Returns the score of the object.
 631                  *
 632                  * @return The score of the object
 633                  */
 634                 public double getScore() {
 635                         return score;
 636                 }
 637
 638         }
 639
 640         /**
 641          * Extracts the object from a {@link Hit}.
 642          *
 643          * @param <T>
 644          *            The type of the object to extract
 645          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 646          */
 647         private static class HitMapper<T> implements Function<Hit<T>, T> {
 648
 649                 /**
 650                  * {@inheritDoc}
 651                  */
 652                 @Override
 653                 public T apply(Hit<T> input) {
 654                         return input.getObject();
 655                 }
 656
 657         }
 658
 659 }