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

   1 /*
   2  * Sone - SearchPage.java - Copyright © 2010–2012 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 java.util.ArrayList;
  21 import java.util.Collection;
  22 import java.util.Collections;
  23 import java.util.Comparator;
  24 import java.util.HashSet;
  25 import java.util.List;
  26 import java.util.Set;
  27 import java.util.logging.Level;
  28 import java.util.logging.Logger;
  29
  30 import net.pterodactylus.sone.data.Post;
  31 import net.pterodactylus.sone.data.PostReply;
  32 import net.pterodactylus.sone.data.Profile;
  33 import net.pterodactylus.sone.data.Profile.Field;
  34 import net.pterodactylus.sone.data.Reply;
  35 import net.pterodactylus.sone.data.Sone;
  36 import net.pterodactylus.sone.web.page.FreenetRequest;
  37 import net.pterodactylus.util.cache.Cache;
  38 import net.pterodactylus.util.cache.CacheException;
  39 import net.pterodactylus.util.cache.CacheItem;
  40 import net.pterodactylus.util.cache.DefaultCacheItem;
  41 import net.pterodactylus.util.cache.MemoryCache;
  42 import net.pterodactylus.util.cache.ValueRetriever;
  43 import net.pterodactylus.util.collection.Pagination;
  44 import net.pterodactylus.util.collection.TimedMap;
  45 import net.pterodactylus.util.collection.filter.Filter;
  46 import net.pterodactylus.util.collection.filter.Filters;
  47 import net.pterodactylus.util.collection.mapper.Mapper;
  48 import net.pterodactylus.util.collection.mapper.Mappers;
  49 import net.pterodactylus.util.logging.Logging;
  50 import net.pterodactylus.util.number.Numbers;
  51 import net.pterodactylus.util.template.Template;
  52 import net.pterodactylus.util.template.TemplateContext;
  53 import net.pterodactylus.util.text.StringEscaper;
  54 import net.pterodactylus.util.text.TextException;
  55
  56 /**
  57  * This page lets the user search for posts and replies that contain certain
  58  * words.
  59  *
  60  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  61  */
  62 public class SearchPage extends SoneTemplatePage {
  63
  64         /** The logger. */
  65         private static final Logger logger = Logging.getLogger(SearchPage.class);
  66
  67         /** Short-term cache. */
  68         private final Cache<List<Phrase>, Set<Hit<Post>>> hitCache = new MemoryCache<List<Phrase>, Set<Hit<Post>>>(new ValueRetriever<List<Phrase>, Set<Hit<Post>>>() {
  69
  70                 @Override
  71                 @SuppressWarnings("synthetic-access")
  72                 public CacheItem<Set<Hit<Post>>> retrieve(List<Phrase> phrases) throws CacheException {
  73                         Set<Post> posts = new HashSet<Post>();
  74                         for (Sone sone : webInterface.getCore().getSones()) {
  75                                 posts.addAll(sone.getPosts());
  76                         }
  77                         return new DefaultCacheItem<Set<Hit<Post>>>(getHits(Filters.filteredSet(posts, Post.FUTURE_POSTS_FILTER), phrases, new PostStringGenerator()));
  78                 }
  79
  80         }, new TimedMap<List<Phrase>, CacheItem<Set<Hit<Post>>>>(300000));
  81
  82         /**
  83          * Creates a new search page.
  84          *
  85          * @param template
  86          *            The template to render
  87          * @param webInterface
  88          *            The Sone web interface
  89          */
  90         public SearchPage(Template template, WebInterface webInterface) {
  91                 super("search.html", template, "Page.Search.Title", webInterface);
  92         }
  93
  94         //
  95         // SONETEMPLATEPAGE METHODS
  96         //
  97
  98         /**
  99          * {@inheritDoc}
 100          */
 101         @Override
 102         protected void processTemplate(FreenetRequest request, TemplateContext templateContext) throws RedirectException {
 103                 super.processTemplate(request, templateContext);
 104                 String query = request.getHttpRequest().getParam("query").trim();
 105                 if (query.length() == 0) {
 106                         throw new RedirectException("index.html");
 107                 }
 108
 109                 List<Phrase> phrases = parseSearchPhrases(query);
 110                 if (phrases.isEmpty()) {
 111                         throw new RedirectException("index.html");
 112                 }
 113
 114                 /* check for a couple of shortcuts. */
 115                 if (phrases.size() == 1) {
 116                         String phrase = phrases.get(0).getPhrase();
 117
 118                         /* is it a Sone ID? */
 119                         redirectIfNotNull(getSoneId(phrase), "viewSone.html?sone=");
 120
 121                         /* is it a post ID? */
 122                         redirectIfNotNull(getPostId(phrase), "viewPost.html?post=");
 123
 124                         /* is it a reply ID? show the post. */
 125                         redirectIfNotNull(getReplyPostId(phrase), "viewPost.html?post=");
 126
 127                         /* is it an album ID? */
 128                         redirectIfNotNull(getAlbumId(phrase), "imageBrowser.html?album=");
 129
 130                         /* is it an image ID? */
 131                         redirectIfNotNull(getImageId(phrase), "imageBrowser.html?image=");
 132                 }
 133
 134                 Set<Sone> sones = webInterface.getCore().getSones();
 135                 Set<Hit<Sone>> soneHits = getHits(sones, phrases, SoneStringGenerator.COMPLETE_GENERATOR);
 136
 137                 Set<Hit<Post>> postHits;
 138                 try {
 139                         postHits = hitCache.get(phrases);
 140                 } catch (CacheException ce1) {
 141                         /* should never happen. */
 142                         logger.log(Level.SEVERE, "Could not get search results from cache!", ce1);
 143                         postHits = Collections.emptySet();
 144                 }
 145
 146                 /* now filter. */
 147                 soneHits = Filters.filteredSet(soneHits, Hit.POSITIVE_FILTER);
 148                 postHits = Filters.filteredSet(postHits, Hit.POSITIVE_FILTER);
 149
 150                 /* now sort. */
 151                 List<Hit<Sone>> sortedSoneHits = new ArrayList<Hit<Sone>>(soneHits);
 152                 Collections.sort(sortedSoneHits, Hit.DESCENDING_COMPARATOR);
 153                 List<Hit<Post>> sortedPostHits = new ArrayList<Hit<Post>>(postHits);
 154                 Collections.sort(sortedPostHits, Hit.DESCENDING_COMPARATOR);
 155
 156                 /* extract Sones and posts. */
 157                 List<Sone> resultSones = Mappers.mappedList(sortedSoneHits, new HitMapper<Sone>());
 158                 List<Post> resultPosts = Mappers.mappedList(sortedPostHits, new HitMapper<Post>());
 159
 160                 /* pagination. */
 161                 Pagination<Sone> sonePagination = new Pagination<Sone>(resultSones, webInterface.getCore().getPreferences().getPostsPerPage()).setPage(Numbers.safeParseInteger(request.getHttpRequest().getParam("sonePage"), 0));
 162                 Pagination<Post> postPagination = new Pagination<Post>(resultPosts, webInterface.getCore().getPreferences().getPostsPerPage()).setPage(Numbers.safeParseInteger(request.getHttpRequest().getParam("postPage"), 0));
 163
 164                 templateContext.set("sonePagination", sonePagination);
 165                 templateContext.set("soneHits", sonePagination.getItems());
 166                 templateContext.set("postPagination", postPagination);
 167                 templateContext.set("postHits", postPagination.getItems());
 168         }
 169
 170         //
 171         // PRIVATE METHODS
 172         //
 173
 174         /**
 175          * Collects hit information for the given objects. The objects are converted
 176          * to a {@link String} using the given {@link StringGenerator}, and the
 177          * {@link #calculateScore(List, String) calculated score} is stored together
 178          * with the object in a {@link Hit}, and all resulting {@link Hit}s are then
 179          * returned.
 180          *
 181          * @param <T>
 182          *            The type of the objects
 183          * @param objects
 184          *            The objects to search over
 185          * @param phrases
 186          *            The phrases to search for
 187          * @param stringGenerator
 188          *            The string generator for the objects
 189          * @return The hits for the given phrases
 190          */
 191         private static <T> Set<Hit<T>> getHits(Collection<T> objects, List<Phrase> phrases, StringGenerator<T> stringGenerator) {
 192                 Set<Hit<T>> hits = new HashSet<Hit<T>>();
 193                 for (T object : objects) {
 194                         String objectString = stringGenerator.generateString(object);
 195                         double score = calculateScore(phrases, objectString);
 196                         hits.add(new Hit<T>(object, score));
 197                 }
 198                 return hits;
 199         }
 200
 201         /**
 202          * Parses the given query into search phrases. The query is split on
 203          * whitespace while allowing to group words using single or double quotes.
 204          * Isolated phrases starting with a “+” are
 205          * {@link Phrase.Optionality#REQUIRED}, phrases with a “-” are
 206          * {@link Phrase.Optionality#FORBIDDEN}.
 207          *
 208          * @param query
 209          *            The query to parse
 210          * @return The parsed phrases
 211          */
 212         private static List<Phrase> parseSearchPhrases(String query) {
 213                 List<String> parsedPhrases = null;
 214                 try {
 215                         parsedPhrases = StringEscaper.parseLine(query);
 216                 } catch (TextException te1) {
 217                         /* invalid query. */
 218                         return Collections.emptyList();
 219                 }
 220
 221                 List<Phrase> phrases = new ArrayList<Phrase>();
 222                 for (String phrase : parsedPhrases) {
 223                         if (phrase.startsWith("+")) {
 224                                 if (phrase.length() > 1) {
 225                                         phrases.add(new Phrase(phrase.substring(1), Phrase.Optionality.REQUIRED));
 226                                 } else {
 227                                         phrases.add(new Phrase("+", Phrase.Optionality.OPTIONAL));
 228                                 }
 229                         } else if (phrase.startsWith("-")) {
 230                                 if (phrase.length() > 1) {
 231                                         phrases.add(new Phrase(phrase.substring(1), Phrase.Optionality.FORBIDDEN));
 232                                 } else {
 233                                         phrases.add(new Phrase("-", Phrase.Optionality.OPTIONAL));
 234                                 }
 235                         } else {
 236                                 phrases.add(new Phrase(phrase, Phrase.Optionality.OPTIONAL));
 237                         }
 238                 }
 239                 return phrases;
 240         }
 241
 242         /**
 243          * Calculates the score for the given expression when using the given
 244          * phrases.
 245          *
 246          * @param phrases
 247          *            The phrases to search for
 248          * @param expression
 249          *            The expression to search
 250          * @return The score of the expression
 251          */
 252         private static double calculateScore(List<Phrase> phrases, String expression) {
 253                 logger.log(Level.FINEST, String.format("Calculating Score for “%s”…", expression));
 254                 double optionalHits = 0;
 255                 double requiredHits = 0;
 256                 int forbiddenHits = 0;
 257                 int requiredPhrases = 0;
 258                 for (Phrase phrase : phrases) {
 259                         String phraseString = phrase.getPhrase().toLowerCase();
 260                         if (phrase.getOptionality() == Phrase.Optionality.REQUIRED) {
 261                                 ++requiredPhrases;
 262                         }
 263                         int matches = 0;
 264                         int index = 0;
 265                         double score = 0;
 266                         while (index < expression.length()) {
 267                                 int position = expression.toLowerCase().indexOf(phraseString, index);
 268                                 if (position == -1) {
 269                                         break;
 270                                 }
 271                                 score += Math.pow(1 - position / (double) expression.length(), 2);
 272                                 index = position + phraseString.length();
 273                                 logger.log(Level.FINEST, String.format("Got hit at position %d.", position));
 274                                 ++matches;
 275                         }
 276                         logger.log(Level.FINEST, String.format("Score: %f", score));
 277                         if (matches == 0) {
 278                                 continue;
 279                         }
 280                         if (phrase.getOptionality() == Phrase.Optionality.REQUIRED) {
 281                                 requiredHits += score;
 282                         }
 283                         if (phrase.getOptionality() == Phrase.Optionality.OPTIONAL) {
 284                                 optionalHits += score;
 285                         }
 286                         if (phrase.getOptionality() == Phrase.Optionality.FORBIDDEN) {
 287                                 forbiddenHits += matches;
 288                         }
 289                 }
 290                 return requiredHits * 3 + optionalHits + (requiredHits - requiredPhrases) * 5 - (forbiddenHits * 2);
 291         }
 292
 293         /**
 294          * Throws a
 295          * {@link net.pterodactylus.sone.web.page.FreenetTemplatePage.RedirectException}
 296          * if the given object is not {@code null}, appending the object to the
 297          * given target URL.
 298          *
 299          * @param object
 300          *            The object on which to redirect
 301          * @param target
 302          *            The target of the redirect
 303          * @throws RedirectException
 304          *             if {@code object} is not {@code null}
 305          */
 306         private static void redirectIfNotNull(String object, String target) throws RedirectException {
 307                 if (object != null) {
 308                         throw new RedirectException(target + object);
 309                 }
 310         }
 311
 312         /**
 313          * If the given phrase contains a Sone ID (optionally prefixed by
 314          * “sone://”), returns said Sone ID, otherwise return {@code null}.
 315          *
 316          * @param phrase
 317          *            The phrase that maybe is a Sone ID
 318          * @return The Sone ID, or {@code null}
 319          */
 320         private String getSoneId(String phrase) {
 321                 String soneId = phrase.startsWith("sone://") ? phrase.substring(7) : phrase;
 322                 return (webInterface.getCore().getSone(soneId, false) != null) ? soneId : null;
 323         }
 324
 325         /**
 326          * If the given phrase contains a post ID (optionally prefixed by
 327          * “post://”), returns said post ID, otherwise return {@code null}.
 328          *
 329          * @param phrase
 330          *            The phrase that maybe is a post ID
 331          * @return The post ID, or {@code null}
 332          */
 333         private String getPostId(String phrase) {
 334                 String postId = phrase.startsWith("post://") ? phrase.substring(7) : phrase;
 335                 return (webInterface.getCore().getPost(postId, false) != null) ? postId : null;
 336         }
 337
 338         /**
 339          * If the given phrase contains a reply ID (optionally prefixed by
 340          * “reply://”), returns the ID of the post the reply belongs to, otherwise
 341          * return {@code null}.
 342          *
 343          * @param phrase
 344          *            The phrase that maybe is a reply ID
 345          * @return The reply’s post ID, or {@code null}
 346          */
 347         private String getReplyPostId(String phrase) {
 348                 String replyId = phrase.startsWith("reply://") ? phrase.substring(8) : phrase;
 349                 return (webInterface.getCore().getReply(replyId, false) != null) ? webInterface.getCore().getReply(replyId, false).getPost().getId() : null;
 350         }
 351
 352         /**
 353          * If the given phrase contains an album ID (optionally prefixed by
 354          * “album://”), returns said album ID, otherwise return {@code null}.
 355          *
 356          * @param phrase
 357          *            The phrase that maybe is an album ID
 358          * @return The album ID, or {@code null}
 359          */
 360         private String getAlbumId(String phrase) {
 361                 String albumId = phrase.startsWith("album://") ? phrase.substring(8) : phrase;
 362                 return (webInterface.getCore().getAlbum(albumId, false) != null) ? albumId : null;
 363         }
 364
 365         /**
 366          * If the given phrase contains an image ID (optionally prefixed by
 367          * “image://”), returns said image ID, otherwise return {@code null}.
 368          *
 369          * @param phrase
 370          *            The phrase that maybe is an image ID
 371          * @return The image ID, or {@code null}
 372          */
 373         private String getImageId(String phrase) {
 374                 String imageId = phrase.startsWith("image://") ? phrase.substring(8) : phrase;
 375                 return (webInterface.getCore().getImage(imageId, false) != null) ? imageId : null;
 376         }
 377
 378         /**
 379          * Converts a given object into a {@link String}.
 380          *
 381          * @param <T>
 382          *            The type of the objects
 383          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 384          */
 385         private static interface StringGenerator<T> {
 386
 387                 /**
 388                  * Generates a {@link String} for the given object.
 389                  *
 390                  * @param object
 391                  *            The object to generate the {@link String} for
 392                  * @return The generated {@link String}
 393                  */
 394                 public String generateString(T object);
 395
 396         }
 397
 398         /**
 399          * Generates a {@link String} from a {@link Sone}, concatenating the name of
 400          * the Sone and all {@link Profile} {@link Field} values.
 401          *
 402          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 403          */
 404         private static class SoneStringGenerator implements StringGenerator<Sone> {
 405
 406                 /** A static instance of a complete Sone string generator. */
 407                 public static final SoneStringGenerator COMPLETE_GENERATOR = new SoneStringGenerator(true);
 408
 409                 /**
 410                  * A static instance of a Sone string generator that will only use the
 411                  * name of the Sone.
 412                  */
 413                 public static final SoneStringGenerator NAME_GENERATOR = new SoneStringGenerator(false);
 414
 415                 /** Whether to generate a string from all data of a Sone. */
 416                 private final boolean complete;
 417
 418                 /**
 419                  * Creates a new Sone string generator.
 420                  *
 421                  * @param complete
 422                  *            {@code true} to use the profile’s fields, {@code false} to
 423                  *            not to use the profile‘s fields
 424                  */
 425                 private SoneStringGenerator(boolean complete) {
 426                         this.complete = complete;
 427                 }
 428
 429                 /**
 430                  * {@inheritDoc}
 431                  */
 432                 @Override
 433                 public String generateString(Sone sone) {
 434                         StringBuilder soneString = new StringBuilder();
 435                         soneString.append(sone.getName());
 436                         Profile soneProfile = sone.getProfile();
 437                         if (soneProfile.getFirstName() != null) {
 438                                 soneString.append(' ').append(soneProfile.getFirstName());
 439                         }
 440                         if (soneProfile.getMiddleName() != null) {
 441                                 soneString.append(' ').append(soneProfile.getMiddleName());
 442                         }
 443                         if (soneProfile.getLastName() != null) {
 444                                 soneString.append(' ').append(soneProfile.getLastName());
 445                         }
 446                         if (complete) {
 447                                 for (Field field : soneProfile.getFields()) {
 448                                         soneString.append(' ').append(field.getValue());
 449                                 }
 450                         }
 451                         return soneString.toString();
 452                 }
 453
 454         }
 455
 456         /**
 457          * Generates a {@link String} from a {@link Post}, concatenating the text of
 458          * the post, the text of all {@link Reply}s, and the name of all
 459          * {@link Sone}s that have replied.
 460          *
 461          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 462          */
 463         private class PostStringGenerator implements StringGenerator<Post> {
 464
 465                 /**
 466                  * {@inheritDoc}
 467                  */
 468                 @Override
 469                 public String generateString(Post post) {
 470                         StringBuilder postString = new StringBuilder();
 471                         postString.append(post.getText());
 472                         if (post.getRecipient() != null) {
 473                                 postString.append(' ').append(SoneStringGenerator.NAME_GENERATOR.generateString(post.getRecipient()));
 474                         }
 475                         for (PostReply reply : Filters.filteredList(webInterface.getCore().getReplies(post), Reply.FUTURE_REPLY_FILTER)) {
 476                                 postString.append(' ').append(SoneStringGenerator.NAME_GENERATOR.generateString(reply.getSone()));
 477                                 postString.append(' ').append(reply.getText());
 478                         }
 479                         return postString.toString();
 480                 }
 481
 482         }
 483
 484         /**
 485          * A search phrase.
 486          *
 487          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 488          */
 489         private static class Phrase {
 490
 491                 /**
 492                  * The optionality of a search phrase.
 493                  *
 494                  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’
 495                  *         Roden</a>
 496                  */
 497                 public enum Optionality {
 498
 499                         /** The phrase is optional. */
 500                         OPTIONAL,
 501
 502                         /** The phrase is required. */
 503                         REQUIRED,
 504
 505                         /** The phrase is forbidden. */
 506                         FORBIDDEN
 507
 508                 }
 509
 510                 /** The phrase to search for. */
 511                 private final String phrase;
 512
 513                 /** The optionality of the phrase. */
 514                 private final Optionality optionality;
 515
 516                 /**
 517                  * Creates a new phrase.
 518                  *
 519                  * @param phrase
 520                  *            The phrase to search for
 521                  * @param optionality
 522                  *            The optionality of the phrase
 523                  */
 524                 public Phrase(String phrase, Optionality optionality) {
 525                         this.optionality = optionality;
 526                         this.phrase = phrase;
 527                 }
 528
 529                 /**
 530                  * Returns the phrase to search for.
 531                  *
 532                  * @return The phrase to search for
 533                  */
 534                 public String getPhrase() {
 535                         return phrase;
 536                 }
 537
 538                 /**
 539                  * Returns the optionality of the phrase.
 540                  *
 541                  * @return The optionality of the phrase
 542                  */
 543                 public Optionality getOptionality() {
 544                         return optionality;
 545                 }
 546
 547                 //
 548                 // OBJECT METHODS
 549                 //
 550
 551                 /**
 552                  * {@inheritDoc}
 553                  */
 554                 @Override
 555                 public int hashCode() {
 556                         return phrase.hashCode() ^ ((optionality == Optionality.FORBIDDEN) ? (0xaaaaaaaa) : ((optionality == Optionality.REQUIRED) ? 0x55555555 : 0));
 557                 }
 558
 559                 /**
 560                  * {@inheritDoc}
 561                  */
 562                 @Override
 563                 public boolean equals(Object object) {
 564                         if (!(object instanceof Phrase)) {
 565                                 return false;
 566                         }
 567                         Phrase phrase = (Phrase) object;
 568                         return (this.optionality == phrase.optionality) && this.phrase.equals(phrase.phrase);
 569                 }
 570
 571         }
 572
 573         /**
 574          * A hit consists of a searched object and the score it got for the phrases
 575          * of the search.
 576          *
 577          * @see SearchPage#calculateScore(List, String)
 578          * @param <T>
 579          *            The type of the searched object
 580          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 581          */
 582         private static class Hit<T> {
 583
 584                 /** Filter for {@link Hit}s with a score of more than 0. */
 585                 public static final Filter<Hit<?>> POSITIVE_FILTER = new Filter<Hit<?>>() {
 586
 587                         @Override
 588                         public boolean filterObject(Hit<?> hit) {
 589                                 return hit.getScore() > 0;
 590                         }
 591
 592                 };
 593
 594                 /** Comparator that sorts {@link Hit}s descending by score. */
 595                 public static final Comparator<Hit<?>> DESCENDING_COMPARATOR = new Comparator<Hit<?>>() {
 596
 597                         @Override
 598                         public int compare(Hit<?> leftHit, Hit<?> rightHit) {
 599                                 return (rightHit.getScore() < leftHit.getScore()) ? -1 : ((rightHit.getScore() > leftHit.getScore()) ? 1 : 0);
 600                         }
 601
 602                 };
 603
 604                 /** The object that was searched. */
 605                 private final T object;
 606
 607                 /** The score of the object. */
 608                 private final double score;
 609
 610                 /**
 611                  * Creates a new hit.
 612                  *
 613                  * @param object
 614                  *            The object that was searched
 615                  * @param score
 616                  *            The score of the object
 617                  */
 618                 public Hit(T object, double score) {
 619                         this.object = object;
 620                         this.score = score;
 621                 }
 622
 623                 /**
 624                  * Returns the object that was searched.
 625                  *
 626                  * @return The object that was searched
 627                  */
 628                 public T getObject() {
 629                         return object;
 630                 }
 631
 632                 /**
 633                  * Returns the score of the object.
 634                  *
 635                  * @return The score of the object
 636                  */
 637                 public double getScore() {
 638                         return score;
 639                 }
 640
 641         }
 642
 643         /**
 644          * Extracts the object from a {@link Hit}.
 645          *
 646          * @param <T>
 647          *            The type of the object to extract
 648          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 649          */
 650         public static class HitMapper<T> implements Mapper<Hit<T>, T> {
 651
 652                 /**
 653                  * {@inheritDoc}
 654                  */
 655                 @Override
 656                 public T map(Hit<T> input) {
 657                         return input.getObject();
 658                 }
 659
 660         }
 661
 662 }