// WikiCode.java // ------------------------------------- // part of YACY // // (C) 2005, 2006 by Alexander Schier, Marc Nause, Franz Brausze // // $LastChangedDate$ // $LastChangedRevision$ // $LastChangedBy$ // // This program 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 2 of the License, or // (at your option) any later version. // // This program 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 this program; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA package net.yacy.data.wiki; import java.io.BufferedReader; import java.io.IOException; import java.util.ArrayList; import java.util.Arrays; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.regex.Pattern; import net.yacy.document.parser.html.CharacterCoding; import net.yacy.server.serverCore; /** Provides methods to handle texts that have been posted in the yacyWiki or other * parts of YaCy which use wiki code, like the blog or the profile. * * @author Alexander Schier [AS], Franz Brausze [FB], Marc Nause [MN] */ public class WikiCode extends AbstractWikiParser implements WikiParser { private static final String EMPTY = ""; private static final String PIPE_ESCAPED = "|"; private static final Pattern REGEX_NOT_CHAR_NUM_OR_UNDERSCORE_PATTERN = Pattern.compile("[^a-zA-Z0-9_]"); private static final Pattern SPACE_PATTERN = Pattern.compile(" "); private static enum Tags { HEADLINE_1("=", "

", "

"), HEADLINE_2("==", "

", "

"), HEADLINE_3("===", "

", "

"), HEADLINE_4("====", "

", "

"), HEADLINE_5("=====", "
", "
"), HEADLINE_6("======", "
", "
"), EMPHASIZE_1("\'\'", "", ""), EMPHASIZE_2("\'\'\'", "", ""), EMPHASIZE_3("\'\'\'\'\'", "", ""), STRIKE("<s>", "</s>", "", ""), UNDERLINE("<u>", "</u>", "", ""); final String openHTML; final String closeHTML; final String openWiki; final String closeWiki; final int openWikiLength; final int closeWikiLength; Tags(final String openWiki, final String closeWiki, final String openHTML, final String closeHTML) { if (openHTML == null || closeHTML == null || openWiki == null || closeWiki == null) { throw new IllegalArgumentException("Parameter may not be null."); } this.openHTML = openHTML; this.closeHTML = closeHTML; this.openWiki = openWiki; this.closeWiki = closeWiki; this.openWikiLength = openWiki.length(); this.closeWikiLength = closeWiki.length(); } Tags(final String wiki, final String openHTML, final String closeHTML) { this(wiki, wiki, openHTML, closeHTML); } } private static final String HTML_OPEN_DEFINITION_DESCRIPTION = "
"; private static final String HTML_CLOSE_DEFINITION_DESCRIPTION = "
"; private static final String HTML_OPEN_DEFINITION_ITEM = "
"; private static final String HTML_CLOSE_DEFINITION_ITEM = "
"; private static final String HTML_OPEN_DEFINITION_LIST = "
"; private static final String HTML_CLOSE_DEFINITION_LIST = "
"; private static final String HTML_OPEN_UNORDERED_LIST = ""; private static final String HTML_CLOSE_BLOCKQUOTE = ""; private static final String HTML_CLOSE_LIST_ELEMENT = ""; private static final String HTML_CLOSE_ORDERED_LIST = ""; private static final String HTML_OPEN_BLOCKQUOTE = "
"; private static final String HTML_OPEN_LIST_ELEMENT = "
  • "; private static final String HTML_OPEN_ORDERED_LIST = "
      "; private static final String WIKI_CLOSE_LINK = "]]"; private static final String WIKI_OPEN_LINK = "[["; /** Wiki template inclusion closing tag */ private static final String WIKI_CLOSE_METADATA = "}}"; /** Wiki template inclusion opening tag */ private static final String WIKI_OPEN_METADATA = "{{"; private static final String WIKI_CLOSE_EXTERNAL_LINK = "]"; private static final String WIKI_OPEN_EXTERNAL_LINK = "["; private static final String WIKI_CLOSE_PRE_ESCAPED = "</pre>"; private static final String WIKI_HR_LINE = "----"; private static final String WIKI_IMAGE = "Image:"; private static final String WIKI_VIDEO_YOUTUBE = "Youtube:"; private static final String WIKI_VIDEO_VIMEO = "Vimeo:"; private static final String WIKI_OPEN_PRE_ESCAPED = "<pre>"; private static final char ASTERISK = '*'; private static final char ONE = '1'; private static final char TWO = '2'; private static final char THREE = '3'; private static final char FOUR = '4'; private static final char FIVE = '5'; private static final char SIX = '6'; private static final char WIKI_FORMATTED = ' '; private static final char WIKI_INDENTION = ':'; /** Wiki template parameter separator */ private static final char WIKI_METADATA_PARAMETER_SEPARATOR = '|'; private static final int LEN_WIKI_CLOSE_PRE_ESCAPED = WIKI_CLOSE_PRE_ESCAPED.length(); private static final int LEN_WIKI_OPEN_PRE_ESCAPED = WIKI_OPEN_PRE_ESCAPED.length(); private static final int LEN_WIKI_OPEN_LINK = WIKI_OPEN_LINK.length(); private static final int LEN_WIKI_CLOSE_LINK = WIKI_CLOSE_LINK.length(); private static final int LEN_WIKI_IMAGE = WIKI_IMAGE.length(); private static final int LEN_WIKI_VIDEO_YOUTUBE = WIKI_VIDEO_YOUTUBE.length(); private static final int LEN_WIKI_VIDEO_VIMEO = WIKI_VIDEO_VIMEO.length(); private static final int LEN_WIKI_OPEN_EXTERNAL_LINK = WIKI_OPEN_EXTERNAL_LINK.length(); private static final int LEN_WIKI_CLOSE_EXTERNAL_LINK = WIKI_CLOSE_EXTERNAL_LINK.length(); private static final int LEN_WIKI_HR_LINE = WIKI_HR_LINE.length(); private static final int LEN_PIPE_ESCAPED = PIPE_ESCAPED.length(); private static final int LEN_WIKI_OPEN_METADATA = WIKI_OPEN_METADATA.length(); private static final int LEN_WIKI_CLOSE_METADATA = WIKI_CLOSE_METADATA.length(); /** List of properties which can be used in tables. */ private final static String[] TABLE_PROPERTIES = {"rowspan", "colspan", "vspace", "hspace", "cellspacing", "cellpadding", "border"}; /** Map which contains possible values for several parameters. */ private final static Map PROPERTY_VALUES = new HashMap(); /** Tags for different types of headlines in wikiCode. */ private final static String[] HEADLINE_TAGS = new String[]{Tags.HEADLINE_6.openWiki, Tags.HEADLINE_5.openWiki, Tags.HEADLINE_4.openWiki, Tags.HEADLINE_3.openWiki, Tags.HEADLINE_2.openWiki, Tags.HEADLINE_1.openWiki}; private final static char[] HEADLINE_LEVEL = new char[]{ONE, TWO, THREE, FOUR, FIVE, SIX}; static { /* Arrays must be sorted since Arrays.searchBinary() is used later. For more info go to * http://java.sun.com/javase/6/docs/api/java/util/Arrays.html#binarySearch(T[], T, java.util.Comparator) */ Arrays.sort(HEADLINE_LEVEL); Arrays.sort(HEADLINE_TAGS); Arrays.sort(TABLE_PROPERTIES); String[] array; Arrays.sort(array = new String[]{"void", "above", "below", "hsides", "lhs", "rhs", "vsides", "box", "border"}); PROPERTY_VALUES.put("frame", array); Arrays.sort(array = new String[]{"none", "groups", "rows", "cols", "all"}); PROPERTY_VALUES.put("rules", array); Arrays.sort(array = new String[]{"top", "middle", "bottom", "baseline"}); PROPERTY_VALUES.put("valign", array); Arrays.sort(array = new String[]{"left", "right", "center"}); PROPERTY_VALUES.put("align", array); } private final String tableStart = "{" + PIPE_ESCAPED; // {| private final String newLine = PIPE_ESCAPED + "-"; // |- private final String cellDivider = PIPE_ESCAPED + PIPE_ESCAPED; // || private final String tableEnd = PIPE_ESCAPED + "}"; // |} private final String attribDivider = PIPE_ESCAPED; // | private final int lenTableStart = this.tableStart.length(); private final int lenCellDivider = this.cellDivider.length(); private final int lenTableEnd = this.tableEnd.length(); private final int lenAttribDivider = this.attribDivider.length(); private enum ListType { ORDERED, UNORDERED; } private String orderedListLevel = EMPTY; private String unorderedListLevel = EMPTY; private String defListLevel = EMPTY; private boolean processingCell = false; //needed for prevention of double-execution of replaceHTML private boolean processingDefList = false; //needed for definition lists private final boolean escape = false; //needed for escape private final boolean escaped = false; //needed for
       not getting in the way
          private boolean newRowStart = false;                //needed for the first row not to be empty
          private boolean noList = false;                     //needed for handling of [= and 
       in lists
          private boolean processingPreformattedText = false; //needed for preformatted text
          private boolean preformattedSpanning = false;       //needed for 
       and 
      spanning over several lines private boolean replacedHtmlAlready = false; //indicates if method replaceHTML has been used with line already private boolean processingTable = false; //needed for tables, because they reach over several lines private int preindented = 0; //needed for indented
      s
      
          private final TableOfContent tableOfContents = new TableOfContent();
      
          /**
           * Transforms a text which contains wiki code to HTML fragment.
           * @param hostport
           * @param reader contains the text to be transformed.
           * @param length expected length of text, used to create buffer with right size.
           * @return HTML fragment.
           * @throws IOException in case input from reader can not be read.
           */
          @Override
          protected String transform(final String hostport, final BufferedReader reader, final int length)
                  throws IOException {
              final StringBuilder out = new StringBuilder(length);
              String line;
              while ((line = reader.readLine()) != null) {
                  out.append(processLineOfWikiCode(hostport, line)).append(serverCore.CRLF_STRING);
              }
              out.insert(0, createTableOfContents());
              this.tableOfContents.clear();
              return out.toString();
          }
      
          private void processHeadline(
                  final StringBuilder input,
                  final int firstPosition,
                  final Tags tags,
                  final int secondPosition,
                  String direlem)
          {
              //add anchor and create headline
              if ((direlem = input.substring(firstPosition + tags.openWikiLength, secondPosition)) != null) {
                  //counting double headlines
                  int doubles = 0;
                  final Iterator iterator = this.tableOfContents.iterator();
                  String element;
                  while (iterator.hasNext()) {
                      element = iterator.next();
                      // no element with null value should ever be in directory
                      assert (element != null);
                      if (element.substring(1).equals(direlem)) {
                          doubles++;
                      }
                  }
                  String anchor = REGEX_NOT_CHAR_NUM_OR_UNDERSCORE_PATTERN.matcher(SPACE_PATTERN.matcher(direlem).replaceAll("_")).replaceAll(EMPTY); //replace blanks with underscores and delete everything thats not a regular character, a number or _
                  //if there are doubles, add underscore and number of doubles plus one
                  if (doubles > 0) {
                      anchor = anchor + "_" + (doubles + 1);
                  }
                  final StringBuilder link = new StringBuilder();
                  link.append("");
                  link.append(tags.openHTML);
                  link.append(direlem);
                  link.append(tags.closeHTML);
      
                  input.replace(firstPosition, secondPosition + tags.closeWikiLength, link.toString());
      
                  //add headlines to list of headlines (so TOC can be created)
                  if (Arrays.binarySearch(HEADLINE_TAGS, tags.openWiki) >= 0) {
                      this.tableOfContents.add((tags.openWikiLength - 1) + direlem);
                  }
              }
          }
      
          // contributed by [FB], changes by [MN]
          /**
           * Processes tags which are connected to tables.
           * @param line line of text to be transformed from wiki code to HTML
           * @return HTML fragment
           */
          private String processTable(final String line) {
      
              final StringBuilder out = new StringBuilder();
      
              if (line.startsWith(this.tableStart) && !this.processingTable) {
                  this.processingTable = true;
                  this.newRowStart = true;
                  out.append(" this.lenTableStart) {
                      out.append(filterTableProperties(line.substring(this.lenTableStart).trim()));
                  }
                  out.append(">");
              } else if (line.startsWith(this.newLine) && this.processingTable) {          // new row
                  if (!this.newRowStart) {
                      out.append("\t\n");
                  } else {
                      this.newRowStart = false;
                  }
                  out.append("\t");
              } else if (line.startsWith(this.cellDivider) && this.processingTable) {
                  out.append("\t\t 0) ? (line.indexOf(this.cellDivider, this.lenCellDivider)) : (line.length());
                  int propEnd = line.indexOf(this.attribDivider, this.lenCellDivider);
                  final int occImage = line.indexOf("[[Image:", this.lenCellDivider);
                  final int occEscape = line.indexOf("[=", this.lenCellDivider);
                  //If resultOf("[[Image:") is less than propEnd, that means that there is no
                  //property for this cell, only an image. Without this, YaCy could get confused
                  //by a | in [[Image:picture.png|alt-text]] or [[Image:picture.png|alt-text]]
                  //Same for [= (part of [= =])
                  if ((propEnd > this.lenCellDivider) && ((occImage > propEnd) || (occImage < 0)) && ((occEscape > propEnd) || (occEscape < 0))) {
                      propEnd = line.indexOf(this.attribDivider, this.lenCellDivider) + this.lenAttribDivider;
                  } else {
                      propEnd = cellEnd;
                  }
                  // both point at same place => new line
                  if (propEnd == cellEnd) {
                      propEnd = this.lenCellDivider;
                  } else {
                      out.append(filterTableProperties(line.substring(this.lenCellDivider, propEnd - this.lenAttribDivider).trim()));
                  }
                  // quick&dirty fix [MN]
                  if (propEnd > cellEnd) {
                      propEnd = this.lenCellDivider;
                  }
                  this.processingTable = false;
                  this.processingCell = true;
                  out.append(">");
                  out.append(processTable(line.substring(propEnd, cellEnd).trim()));
                  out.append("");
                  this.processingTable = true;
                  this.processingCell = false;
                  if (cellEnd < line.length()) {
                      out.append("\n");
                      out.append(processTable(line.substring(cellEnd)));
                  }
              } else if (line.startsWith(this.tableEnd) && (this.processingTable)) {          // Table end
                  this.processingTable = false;
                  out.append("\t\n");
                  out.append(line.substring(this.lenTableEnd));
              } else {
                  out.append(line);
              }
              return out.toString();
          }
      
          // contributed by [MN], changes by [FB]
          /** Takes possible table properties and tests if they are valid.
           * Valid in this case means if they are a property for the table, tr or td
           * tag as stated in the HTML Pocket Reference by Jennifer Niederst (1st edition)
           * The method is important to avoid XSS attacks on the wiki via table properties.
           * @param properties String which may contain several table properties and/or junk.
           * @return String containing only table properties.
           */
          private static StringBuilder filterTableProperties(final String properties) {
              final String[] values = properties.replaceAll(""", EMPTY).split("[= ]");     //splitting the string at = and blanks
              final StringBuilder stringBuilder = new StringBuilder(properties.length());
              String key, value;
              String[] posVals;
              final int numberOfValues = values.length;
              for (int i = 0; i < numberOfValues; i++) {
                  key = values[i].trim();
                  if ("nowrap".equals(key)) {
                      appendKeyValuePair("nowrap", "nowrap", stringBuilder);
                  } else if (i + 1 < numberOfValues) {
                      value = values[++i].trim();
                      if (("summary".equals(key))
                              || ("bgcolor".equals(key) && value.matches("#{0,1}[0-9a-fA-F]{1,6}|[a-zA-Z]{3,}"))
                              || (("width".equals(key) || "height".equals(key)) && value.matches("\\d+%{0,1}"))
                              || ((posVals = PROPERTY_VALUES.get(key)) != null && Arrays.binarySearch(posVals, value) >= 0)
                              || (Arrays.binarySearch(TABLE_PROPERTIES, key) >= 0 && value.matches("\\d+"))) {
                          appendKeyValuePair(key, value, stringBuilder);
                      }
                  }
              }
              return stringBuilder;
          }
      
          /**
           * Appends a key/value pair in HTML syntax to a given StringBuilder.
           * @param key key to be appended.
           * @param value value of key.
           * @param stringBuilder this is what key/value are appended to.
           * @return
           */
          private static StringBuilder appendKeyValuePair(final String key, final String value, final StringBuilder stringBuilder) {
              return stringBuilder.append(" ").append(key).append("=\"").append(value).append("\"");
          }
      
          /**
           * Processes tags which are connected to ordered lists.
           * @param line line of text to be transformed from wiki code to HTML
           * @return HTML fragment
           */
          private String processOrderedList(final String line) {
              return processList(line, ListType.ORDERED);
          }
      
          /**
           * Processes tags which are connected to unordered lists.
           * @param line line of text to be transformed from wiki code to HTML
           * @return HTML fragment
           */
          private String processUnorderedList(final String line) {
              return processList(line, ListType.UNORDERED);
          }
      
          /**
           * Processes tags which are connected to ordered or unordered lists.
           * @author contains code by [AS]
           * @param line line of text to be transformed from wiki code to HTML
           * @param listType type of tags to be processed
           * @return HTML fragment
           */
          private String processList(final String line, final ListType listType) {
      
              final String ret;
      
              if (!this.noList) {    //lists only get processed if not forbidden (see code for [= and 
      ).
      
                  String listLevel;
                  final String htmlOpenList;
                  final String htmlCloseList;
                  final char symbol;
      
                  if (ListType.ORDERED.equals(listType)) {
                      listLevel = this.orderedListLevel;
                      symbol = '#';
                      htmlOpenList = HTML_OPEN_ORDERED_LIST;
                      htmlCloseList = HTML_CLOSE_ORDERED_LIST;
                  } else if (ListType.UNORDERED.equals(listType)) {
                      listLevel = this.unorderedListLevel;
                      symbol = ASTERISK;
                      htmlOpenList = HTML_OPEN_UNORDERED_LIST;
                      htmlCloseList = HTML_CLOSE_UNORDERED_LIST;
                  } else {
                      throw new IllegalArgumentException("Unknown list type " + listType);
                  }
      
                  if (line.startsWith(listLevel + symbol)) {      //more #
                      final StringBuilder stringBuilder = new StringBuilder();
                      stringBuilder.append(htmlOpenList);
                      stringBuilder.append(serverCore.CRLF_STRING);
                      stringBuilder.append(HTML_OPEN_LIST_ELEMENT);
                      stringBuilder.append(line.substring(listLevel.length() + 1).trim());
                      stringBuilder.append(HTML_CLOSE_LIST_ELEMENT);
                      ret = stringBuilder.toString();
                      listLevel += symbol;
                  } else if (!listLevel.isEmpty() && line.startsWith(listLevel)) {           //equal number of #
                      final StringBuilder stringBuilder = new StringBuilder();
                      stringBuilder.append(HTML_OPEN_LIST_ELEMENT);
                      stringBuilder.append(line.substring(listLevel.length()).trim());
                      stringBuilder.append(HTML_CLOSE_LIST_ELEMENT);
                      ret = stringBuilder.toString();
                  } else if (!listLevel.isEmpty()) {            //less #
                      final StringBuilder stringBuilder = new StringBuilder();
                      final StringBuilder tmp = new StringBuilder();
      
                      int i = listLevel.length();
                      while (!line.startsWith(listLevel.substring(0, i))) {
                          tmp.append(htmlCloseList);
                          i--;
                      }
                      listLevel = listLevel.substring(0, i);
      
                      final int startOfContent = listLevel.length();
      
                      if (startOfContent > 0) {
                          stringBuilder.append(tmp);
                          stringBuilder.append(HTML_OPEN_LIST_ELEMENT);
                          stringBuilder.append(line.substring(startOfContent).trim());
                          stringBuilder.append(HTML_CLOSE_LIST_ELEMENT);
                      } else {
                          stringBuilder.append(tmp);
                          stringBuilder.append(line.substring(startOfContent).trim());
                      }
                      ret = stringBuilder.toString();
                  }  else {
                      ret = line;
                  }
      
                  if (ListType.ORDERED.equals(listType)) {
                      this.orderedListLevel = listLevel;
                  } else if (ListType.UNORDERED.equals(listType)) {
                      this.unorderedListLevel = listLevel;
                  }
              } else {
                  ret = line;
              }
              return ret;
          }
      
          /**
           * Processes tags which are connected to definition lists.
           * @param line line of text to be transformed from wiki code to HTML
           * @return HTML fragment
           */
          private String processDefinitionList(final String line) {
              final String ret;
      
              if (!this.noList) {    //lists only get processed if not forbidden (see code for [= and 
      ). [MN]
      
                  if (line.startsWith(this.defListLevel + ";")) { //more semicolons
                      final String copyOfLine = line.substring(this.defListLevel.length() + 1);
                      final int positionOfOpeningTag;
                      if ((positionOfOpeningTag = copyOfLine.indexOf(':',0)) > 0) {
                          final String definitionItem = copyOfLine.substring(0, positionOfOpeningTag);
                          final String definitionDescription = copyOfLine.substring(positionOfOpeningTag + 1);
                          final StringBuilder stringBuilder = new StringBuilder();
                          stringBuilder.append(HTML_OPEN_DEFINITION_LIST);
                          stringBuilder.append(HTML_OPEN_DEFINITION_ITEM);
                          stringBuilder.append(definitionItem);
                          stringBuilder.append(HTML_CLOSE_DEFINITION_ITEM);
                          stringBuilder.append(HTML_OPEN_DEFINITION_DESCRIPTION);
                          stringBuilder.append(definitionDescription);
                          this.processingDefList = true;
                          ret = stringBuilder.toString();
                      } else {
                          ret = line;
                      }
                      this.defListLevel += ";";
                  } else if (!this.defListLevel.isEmpty() && line.startsWith(this.defListLevel)) { //equal number of semicolons
                      final String copyOfLine = line.substring(this.defListLevel.length());
                      final int positionOfOpeningTag;
                      if ((positionOfOpeningTag = copyOfLine.indexOf(':',0)) > 0) {
                          final String definitionItem = copyOfLine.substring(0, positionOfOpeningTag);
                          final String definitionDescription = copyOfLine.substring(positionOfOpeningTag + 1);
                          final StringBuilder stringBuilder = new StringBuilder();
                          stringBuilder.append(HTML_OPEN_DEFINITION_ITEM);
                          stringBuilder.append(definitionItem);
                          stringBuilder.append(HTML_CLOSE_DEFINITION_ITEM);
                          stringBuilder.append(HTML_OPEN_DEFINITION_DESCRIPTION);
                          stringBuilder.append(definitionDescription);
                          this.processingDefList = true;
                          ret = stringBuilder.toString();
                      } else {
                          ret = line;
                      }
                  } else if (!this.defListLevel.isEmpty()) { //less semicolons
                      int i = this.defListLevel.length();
                      String tmp = EMPTY;
                      while (!line.startsWith(this.defListLevel.substring(0, i))) {
                          tmp = HTML_CLOSE_DEFINITION_DESCRIPTION + HTML_CLOSE_DEFINITION_LIST;
                          i--;
                      }
                      this.defListLevel = this.defListLevel.substring(0, i);
                      int positionOfOpeningTag = this.defListLevel.length();
                      if (!this.defListLevel.isEmpty()) {
                          final String copyOfLine = line.substring(positionOfOpeningTag);
                          if ((positionOfOpeningTag = copyOfLine.indexOf(':',0)) > 0) {
                              final String definitionItem = copyOfLine.substring(0, positionOfOpeningTag);
                              final String definitionDescription = copyOfLine.substring(positionOfOpeningTag + 1);
                              final StringBuilder stringBuilder = new StringBuilder();
                              stringBuilder.append(tmp);
                              stringBuilder.append(HTML_OPEN_DEFINITION_ITEM);
                              stringBuilder.append(definitionItem);
                              stringBuilder.append(HTML_CLOSE_DEFINITION_ITEM);
                              stringBuilder.append(HTML_OPEN_DEFINITION_DESCRIPTION);
                              stringBuilder.append(definitionDescription);
                              this.processingDefList = true;
                              ret = stringBuilder.toString();
                          } else {
                              ret = line;
                          }
                      } else {
                          final StringBuilder stringBuilder = new StringBuilder();
                          stringBuilder.append(tmp);
                          stringBuilder.append(line.substring(positionOfOpeningTag));
                          ret = stringBuilder.toString();
                      }
                  } else {
                      ret = line;
                  }
              } else {
                  ret = line;
              }
              return ret;
          }
      
          /**
           * Processes tags which are connected to links and images.
           * @author [AS], [MN]
           * @param hostport (optional) host and port, added when not empty as the base of relative Wiki link URLs.
           * @param line line of text to be transformed from wiki code to HTML
           * @return HTML fragment
           */
          private static String processLinksAndImages(final String hostport, String line) {
      
              // create links
              String kl, kv, alt, align;
              int p;
              int positionOfOpeningTag;
              int positionOfClosingTag;
              int fromIndex = 0;
              // internal links and images
              while ((positionOfOpeningTag = line.indexOf(WIKI_OPEN_LINK, fromIndex)) >= 0) {
                  positionOfClosingTag = line.indexOf(WIKI_CLOSE_LINK, positionOfOpeningTag + LEN_WIKI_OPEN_LINK);
                  if (positionOfClosingTag <= positionOfOpeningTag) {
                      break;
                  }
                  kl = line.substring(positionOfOpeningTag + LEN_WIKI_OPEN_LINK, positionOfClosingTag);
      
                  // this is the part of the code that's responsible for images
                  if (kl.startsWith(WIKI_IMAGE)) {
                      alt = EMPTY;
                      align = EMPTY;
                      kv = EMPTY;
                      kl = kl.substring(LEN_WIKI_IMAGE);
      
                      // are there any arguments for the image?
                      if ((p = kl.indexOf(PIPE_ESCAPED)) > 0) {
                          kv = kl.substring(p + LEN_WIKI_IMAGE);
                          kl = kl.substring(0, p);
                          // if there are 2 arguments, write them into ALIGN and ALT
                          if ((p = kv.indexOf(PIPE_ESCAPED)) > 0) {
                              align = kv.substring(0, p);
                              //checking validity of value for align. Only non browser specific
                              //values get supported. Not supported: absmiddle, baseline, texttop
                              if (("bottom".equals(align))
                                      || ("center".equals(align))
                                      || ("left".equals(align))
                                      || ("middle".equals(align))
                                      || ("right".equals(align))
                                      || ("top".equals(align))) {
                                  align = " align=\"" + align + "\"";
                              } else {
                                  align = EMPTY;
                              }
                              alt = " alt=\"" + kv.substring(p + LEN_WIKI_IMAGE) + "\"";
                          } // if there is just one, put it into ALT
                          else {
                              alt = " alt=\"" + kv + "\"";
                          }
                      }
      
                      // eventually replace incomplete URLs and make them point to http://peerip:port/...
                      // with this feature you can access an image in DATA/HTDOCS/share/yacy.gif
                      // using the wikicode [[Image:share/yacy.gif]]
                      // or an image DATA/HTDOCS/grafics/kaskelix.jpg with [[Image:grafics/kaskelix.jpg]]
                      // you are free to use other sub-paths of DATA/HTDOCS
                      if (kl.indexOf("://",0) < 1 && hostport != null && !hostport.isEmpty()) {
                          kl = "http://" + hostport + "/" + kl;
                      }
      
                      line = line.substring(0, positionOfOpeningTag) + "" + line.substring(positionOfClosingTag + LEN_WIKI_CLOSE_LINK);
                      fromIndex = positionOfClosingTag + LEN_WIKI_CLOSE_LINK;
                  }
                  // this is the part of the code that is responsible for Youtube video links supporting only the video ID as parameter
                  else if (kl.startsWith(WIKI_VIDEO_YOUTUBE)) {
                  	kl = kl.substring(LEN_WIKI_VIDEO_YOUTUBE);
                  	line = line.substring(0, positionOfOpeningTag) + "" + "";
                  	break;
                  }
                  // this is the part of the code that is responsible for Vimeo video links supporting only the video ID as parameter
                  else if (kl.startsWith(WIKI_VIDEO_VIMEO)) {
                  	kl = kl.substring(LEN_WIKI_VIDEO_VIMEO);
                  	line = line.substring(0, positionOfOpeningTag) + "" + "";
                  	break;
                  }
                  // if it's no image, it might be an internal link
                  else {
                      if ((p = kl.indexOf(PIPE_ESCAPED)) > 0) {
                          kv = kl.substring(p + LEN_PIPE_ESCAPED);
                          kl = kl.substring(0, p);
                      } else {
                          kv = kl;
                      }
                      line = line.substring(0, positionOfOpeningTag) + "" + kv + "" + line.substring(positionOfClosingTag + LEN_WIKI_CLOSE_LINK); // oob exception in append() !
                      fromIndex = positionOfClosingTag + LEN_WIKI_CLOSE_LINK;
                  }
              }
              
              fromIndex = 0;
              // external links
              while ((positionOfOpeningTag = line.indexOf(WIKI_OPEN_EXTERNAL_LINK, fromIndex)) >= 0) {
                  positionOfClosingTag = line.indexOf(WIKI_CLOSE_EXTERNAL_LINK, positionOfOpeningTag + LEN_WIKI_OPEN_EXTERNAL_LINK);
                  if (positionOfClosingTag <= positionOfOpeningTag) {
                      break;
                  }
                  kl = line.substring(positionOfOpeningTag + LEN_WIKI_OPEN_EXTERNAL_LINK, positionOfClosingTag);
                  if ((p = kl.indexOf(' ',0)) > 0) {
                      kv = kl.substring(p + 1);
                      kl = kl.substring(0, p);
                  } // No text for the link? -> http://www.url.com/
                  else {
                      kv = kl;
                  }
                  // eventually replace incomplete URLs and make them point to http://peerip:port/...
                  // with this feature you can access a file at DATA/HTDOCS/share/page.html
                  // using the wikicode [share/page.html]
                  // or a file DATA/HTDOCS/www/page.html with [www/page.html]
                  // you are free to use other sub-paths of DATA/HTDOCS
                  if (kl.indexOf("://",0) < 1 && hostport != null && !hostport.isEmpty()) {
                      kl = "http://" + hostport + "/" + kl;
                  }
                  line = line.substring(0, positionOfOpeningTag) + "" + kv + "" + line.substring(positionOfClosingTag + LEN_WIKI_CLOSE_EXTERNAL_LINK);
                  fromIndex = positionOfClosingTag + LEN_WIKI_CLOSE_EXTERNAL_LINK;
              }
              return line;
          }
      
          /**
           * Processes tags which are connected preformatted text (<pre> </pre>).
           * @param hostport
           * @param line line of text to be transformed from wiki code to HTML
           * @return HTML fragment
           */
          private String processPreformattedText(final String hostport, String line) {
              if (!this.escaped) {
                  final int positionOfOpeningTag = line.indexOf(WIKI_OPEN_PRE_ESCAPED);
                  final int positionOfClosingTag = line.indexOf(WIKI_CLOSE_PRE_ESCAPED);
                  //both 
       and 
      in the same line if (positionOfOpeningTag >= 0 && positionOfClosingTag > 0) { if (positionOfOpeningTag < positionOfClosingTag) { final StringBuilder preformattedText = new StringBuilder(); preformattedText.append("
      ");
                          preformattedText.append(line.substring(positionOfOpeningTag + LEN_WIKI_OPEN_PRE_ESCAPED, positionOfClosingTag));
                          preformattedText.append("
      "); line = processLineOfWikiCode(hostport, line.substring(0, positionOfOpeningTag).replaceAll("!pre!", "!pre!!") + "!pre!txt!" + line.substring(positionOfClosingTag + LEN_WIKI_CLOSE_PRE_ESCAPED).replaceAll("!pre!", "!pre!!")); line = line.replace("!pre!txt!", preformattedText.toString().replaceAll("!pre!", "!pre!!")); line = line.replaceAll("!pre!!", "!pre!"); } //handles cases like
       
       
      that would cause an exception otherwise else { this.processingPreformattedText = true; final String temp1 = processLineOfWikiCode(hostport, line.substring(0, positionOfOpeningTag - 1).replaceAll("!tmp!", "!tmp!!") + "!tmp!txt!"); this.noList = true; final String temp2 = processLineOfWikiCode(hostport, line.substring(positionOfOpeningTag)); this.noList = false; line = temp1.replaceAll("!tmp!txt!", temp2); line = line.replaceAll("!tmp!!", "!tmp!"); this.processingPreformattedText = false; } } //start
                  else if (positionOfOpeningTag >= 0 && !this.preformattedSpanning) {
                      this.processingPreformattedText = true;    //prevent surplus line breaks
                      final StringBuilder openBlockQuoteTags = new StringBuilder();  //gets filled with 
      s as needed String preformattedText = "
      " + line.substring(positionOfOpeningTag + LEN_WIKI_OPEN_PRE_ESCAPED);
                      preformattedText = preformattedText.replaceAll("!pre!", "!pre!!");
                      //taking care of indented lines
                      while (this.preindented < positionOfOpeningTag && positionOfOpeningTag < line.length() &&
                              line.substring(this.preindented, positionOfOpeningTag).charAt(0) == WIKI_INDENTION) {
                          this.preindented++;
                          openBlockQuoteTags.append(HTML_OPEN_BLOCKQUOTE);
                      }
                      line = processLineOfWikiCode(hostport, line.substring(this.preindented, positionOfOpeningTag).replaceAll("!pre!", "!pre!!") + "!pre!txt!");
                      line = openBlockQuoteTags + line.replace("!pre!txt!", preformattedText);
                      line = line.replaceAll("!pre!!", "!pre!");
                      this.preformattedSpanning = true;
                  } //end 
      else if (positionOfClosingTag >= 0 && this.preformattedSpanning) { this.preformattedSpanning = false; final StringBuilder endBlockQuoteTags = new StringBuilder(); //gets filled with
      s as needed String preformattedText = line.substring(0, positionOfClosingTag) + "
      "; preformattedText = preformattedText.replaceAll("!pre!", "!pre!!"); //taking care of indented lines while (this.preindented > 0) { endBlockQuoteTags.append(HTML_CLOSE_BLOCKQUOTE); this.preindented--; } line = processLineOfWikiCode(hostport, "!pre!txt!" + line.substring(positionOfClosingTag + LEN_WIKI_CLOSE_PRE_ESCAPED).replaceAll("!pre!", "!pre!!")); line = line.replace("!pre!txt!", preformattedText) + endBlockQuoteTags; line = line.replaceAll("!pre!!", "!pre!"); this.processingPreformattedText = false; } //Getting rid of surplus
      else if (positionOfOpeningTag >= 0 && !this.preformattedSpanning) { int posTag; while ((posTag = line.indexOf(WIKI_CLOSE_PRE_ESCAPED)) >= 0) { line = line.substring(0, posTag) + line.substring(posTag + LEN_WIKI_CLOSE_PRE_ESCAPED); } line = processLineOfWikiCode(hostport, line); } } return line; } /** Creates table of contents for a wiki page. * @return HTML fragment */ private StringBuilder createTableOfContents() { final StringBuilder directory = new StringBuilder(); String element; int s = 0; int level = 1; int level1 = 0; int level2 = 0; int level3 = 0; int level4 = 0; int level5 = 0; int level6 = 0; int doubles = 0; String anchorext = EMPTY; if ((s = this.tableOfContents.size()) > 2) { directory.append("
      \n"); for (int i = 0; i < s; i++) { if (i >= this.tableOfContents.size()) { break; } element = this.tableOfContents.get(i); if (element == null) { continue; } //counting double headlines doubles = 0; for (int j = 0; j < i; j++) { if (j >= this.tableOfContents.size()) { break; } final String d = this.tableOfContents.get(j); if (d == null || d.isEmpty()) { continue; } final String a = REGEX_NOT_CHAR_NUM_OR_UNDERSCORE_PATTERN.matcher(SPACE_PATTERN.matcher(d.substring(1)).replaceAll("_")).replaceAll(EMPTY); final String b = REGEX_NOT_CHAR_NUM_OR_UNDERSCORE_PATTERN.matcher(SPACE_PATTERN.matcher(element.substring(1)).replaceAll("_")).replaceAll(EMPTY); if (a.equals(b)) { doubles++; } } //if there are doubles, create anchor extension if (doubles > 0) { anchorext = "_" + (doubles + 1); } final char l = element.charAt(0); String temp = ""; if (Arrays.binarySearch(HEADLINE_LEVEL, l) >= 0 && !element.isEmpty()) { switch (l) { case SIX: { if (level < 6) { level = 6; level6 = 0; } level6++; temp = element.substring(1); element = level1 + "." + level2 + "." + level3 + "." + level4 + "." + level5 + "." + level6 + " " + temp; directory.append("             1) { level = 1; level2 = 0; level3 = 0; level4 = 0; level5 = 0; level6 = 0; } level1++; temp = element.substring(1); element = level1 + ". " + temp; directory.append(""); directory.append(element); directory.append("
      \n"); } anchorext = EMPTY; } directory.append("
      \n"); } return directory; } /** * Replaces the wiki representation of tags with the HTML representation. * @param input String which potentially contains tags to be replaced. * @param tags tags to be replaced. * @return String with replaced tags. */ private String tagReplace(final String input, final Tags tags) { final String direlem = null; //string to keep headlines until they get added to List dirElements final StringBuilder stringBuilder = new StringBuilder(input); int firstPosition = 0; int secondPosition = 0; //replace pattern if a pair of the pattern can be found in the line while (((firstPosition = stringBuilder.indexOf(tags.openWiki, secondPosition)) >= 0) && ((secondPosition = stringBuilder.indexOf(tags.closeWiki, firstPosition + tags.openWikiLength)) >= 0)) { //extra treatment for headlines if (Arrays.binarySearch(HEADLINE_TAGS, tags.openWiki) >= 0) { // require line starts with headline markup (hdr e.g. " == Title == " but not "Seven = six plus one" ) int i = 0; boolean beginsWith = true; while (i < firstPosition) { if (stringBuilder.charAt(i) > ' ') { beginsWith = false; break; } i++; } if (beginsWith) processHeadline(stringBuilder, firstPosition, tags, secondPosition, direlem); } else { final int oldLength = stringBuilder.length(); stringBuilder.replace(firstPosition, firstPosition + tags.openWikiLength, tags.openHTML); secondPosition += stringBuilder.length() - oldLength; stringBuilder.replace(secondPosition, secondPosition + tags.closeWikiLength, tags.closeHTML); } } return stringBuilder.toString(); } /** Replaces wiki tags with HTML tags in one line of text. * @param hostport * @param line line of text to be transformed from wiki code to HTML * @return HTML fragment */ private String processLineOfWikiCode(final String hostport, String line) { //If HTML has not been replaced yet (can happen if method gets called in recursion), replace now! line = processMetadata(line); if ((!this.replacedHtmlAlready || this.preformattedSpanning) && line.indexOf(WIKI_CLOSE_PRE_ESCAPED) < 0) { line = CharacterCoding.unicode2html(line, true); this.replacedHtmlAlready = true; } //check if line contains preformatted symbols or if we are in a preformatted sequence already. if ((line.indexOf(WIKI_OPEN_PRE_ESCAPED) >= 0) || (line.indexOf(WIKI_CLOSE_PRE_ESCAPED) >= 0) || this.preformattedSpanning) { line = processPreformattedText(hostport, line); } else { //tables first -> wiki-tags in cells can be treated after that line = processTable(line); // format lines if (!line.isEmpty() && line.charAt(0) == WIKI_FORMATTED) { line = "" + line.substring(1) + ""; } if (line.startsWith(WIKI_HR_LINE)) { line = "
      " + line.substring(LEN_WIKI_HR_LINE); } if (!line.isEmpty() && line.charAt(0) == WIKI_INDENTION) { final StringBuilder head = new StringBuilder(); final StringBuilder tail = new StringBuilder(); while (!line.isEmpty() && line.charAt(0) == WIKI_INDENTION) { head.append(HTML_OPEN_BLOCKQUOTE); tail.append(HTML_CLOSE_BLOCKQUOTE); line = line.substring(1); } line = head + line + tail; } // format headers line = tagReplace(line, Tags.HEADLINE_6); line = tagReplace(line, Tags.HEADLINE_5); line = tagReplace(line, Tags.HEADLINE_4); line = tagReplace(line, Tags.HEADLINE_3); line = tagReplace(line, Tags.HEADLINE_2); line = tagReplace(line, Tags.HEADLINE_1); line = tagReplace(line, Tags.EMPHASIZE_3); line = tagReplace(line, Tags.EMPHASIZE_2); line = tagReplace(line, Tags.EMPHASIZE_1); line = tagReplace(line, Tags.STRIKE); line = tagReplace(line, Tags.UNDERLINE); line = processUnorderedList(line); line = processOrderedList(line); line = processDefinitionList(line); line = processLinksAndImages(hostport, line); } if (!this.processingPreformattedText) { this.replacedHtmlAlready = false; } if (!(line.endsWith(HTML_CLOSE_LIST_ELEMENT) || this.processingDefList || this.escape || this.processingPreformattedText || this.processingTable || this.processingCell)) { line += "
      "; } return line; } /** * Process template inclusions in line, eventually with geo coordinate metadata * @param line line of wiki text * @return cleaned text with eventual geo coordinates formatted to be recognizable by parser * @see Wikipedia:Transclusion */ protected static String processMetadata(final String line) { StringBuilder processedLine = new StringBuilder(line); int openIndex, closeIndex, fromIndex = 0; while ((openIndex = processedLine.indexOf(WIKI_OPEN_METADATA, fromIndex)) >= 0) { closeIndex = processedLine.indexOf(WIKI_CLOSE_METADATA, openIndex + LEN_WIKI_OPEN_METADATA); /* Closing tag position : handle eventually nested tags */ int nextOpenIndex = processedLine.indexOf(WIKI_OPEN_METADATA, openIndex + LEN_WIKI_OPEN_METADATA); while(nextOpenIndex >= 0 && nextOpenIndex < closeIndex) { closeIndex = processedLine.indexOf(WIKI_CLOSE_METADATA, closeIndex + LEN_WIKI_CLOSE_METADATA); if(closeIndex < 0) { /* Parent closing mark is missing: likely a multi-line template inclusion */ break; } nextOpenIndex = processedLine.indexOf(WIKI_OPEN_METADATA, nextOpenIndex + LEN_WIKI_OPEN_METADATA); } if(closeIndex > 0) { final String content = processedLine.substring(openIndex + LEN_WIKI_OPEN_METADATA, closeIndex); if (content.toLowerCase(Locale.ROOT).startsWith("coordinate")) { // parse Geographical Coordinates as described in // http://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style_%28dates_and_numbers%29#Geographical_coordinates // looks like: // {{Coord|57|18|22.5|N|4|27|32.7|W|display=title}} // however, such information does not appear as defined above but as: // {{coordinate|NS=52.205944|EW=0.117593|region=GB-CAM|type=landmark}} // {{coordinate|NS=43/50/29/N|EW=73/23/17/W|type=landmark|region=US-NY}} // and if passed through this parser: // {{Coordinate |NS 45/37/43.0/N |EW. 07/58/41.0/E |type=landmark |region=IT-BI}} ## means: degree/minute/second // {{Coordinate |NS 51.48994 |EW. 7.33249 |type=landmark |region=DE-NW}} final String b[] = content.split("\\|"); float lon = Float.NaN, lat = Float.NaN; // degree float lonm = 0.0f, latm = 0.0f; // minutes (including sec as fraction) String lono = "E", lato = "N"; String name = ""; try { for (final String c : b) { if (c.toLowerCase(Locale.ROOT).startsWith("name=")) { name = c.substring(5); } if (c.toUpperCase().startsWith("NS=")) { final String d[] = c.substring(3).split("/"); if (d.length == 1) {float l = Float.parseFloat(d[0]); if (l < 0) {lato = "S"; l = -l;} lat = (float) Math.floor(l); latm = 60.0f * (l - lat);} else if (d.length > 1) { //format: NS deg/min/sec/N lat = Float.parseFloat(d[0]); // degree if (!d[1].isEmpty()) latm = Float.parseFloat(d[1]); // minutes if (d.length >= 3 && !d[2].isEmpty()) {latm += (Float.parseFloat(d[2]) / 60.0f);} // sec (check empty because format found "45/10//N" ) if (d[d.length - 1].toUpperCase().equals("S")) lato = "S"; } } if (c.toUpperCase().startsWith("EW=")) { final String d[] = c.substring(3).split("/"); if (d.length == 1) {float l = Float.parseFloat(d[0]); if (l < 0) {lono = "W"; l = -l;} lon = (float) Math.floor(l); lonm = 60.0f * (l - lon);} else if (d.length > 1) { lon = Float.parseFloat(d[0]); if (!d[1].isEmpty()) lonm = Float.parseFloat(d[1]); if (d.length >= 3 && !d[2].isEmpty()) {lonm += (Float.parseFloat(d[2]) / 60.0f);} if (d[d.length-1].toUpperCase().equals("W")) {lono = "W";} } } } } catch (NumberFormatException nsExcept) { // catch parseFloat exception (may still happen if wiki code contains expressions) processedLine.delete(closeIndex, closeIndex + LEN_WIKI_CLOSE_METADATA); processedLine.delete(openIndex, openIndex + LEN_WIKI_OPEN_METADATA); fromIndex = openIndex; continue; } if (!Float.isNaN(lon) && !Float.isNaN(lat)) { // replace this with a format that the html parser can understand final String htmlCoord = (name.length() > 0 ? (" " + name) : "") + WIKI_FORMATTED +" " + lato + " " + lat + "\u00B0 " + latm + "'" + lono + " " + lon + "\u00B0 " + lonm + "'" + WIKI_FORMATTED; processedLine.replace(openIndex, closeIndex + LEN_WIKI_CLOSE_METADATA, htmlCoord); /* Set next position to openIndex as some parameters can still contain nested template inclusion tags */ fromIndex = openIndex; continue; } fromIndex = closeIndex; // continue with next position } else { String processedContent; /* Any other template inclusion : only remove opening and closing tag and parameter separators */ int nestedOpenTagIndex = content.indexOf(WIKI_OPEN_METADATA); int lastNestedCloseTagIndex = content.lastIndexOf(WIKI_CLOSE_METADATA); if(nestedOpenTagIndex >= 0 && lastNestedCloseTagIndex > 0) { processedContent = WIKI_FORMATTED + content.substring(0, nestedOpenTagIndex).replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' ') + content.substring(nestedOpenTagIndex, lastNestedCloseTagIndex) + content.substring(lastNestedCloseTagIndex).replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' ') + WIKI_FORMATTED; fromIndex = openIndex; // continue with next nested position } else { /* No nested tag : we can now replace parameter separators with spaces in all remaining content */ processedContent = WIKI_FORMATTED + content.replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' ') + WIKI_FORMATTED; fromIndex = openIndex + processedContent.length(); // continue with next position } processedLine.replace(openIndex, closeIndex + LEN_WIKI_CLOSE_METADATA, processedContent); } } else { /* Multi-line template inclusion : only remove opening tag and parameter separators until eventually first nested tag */ int nestedOpenTagIndex = processedLine.indexOf(WIKI_OPEN_METADATA, openIndex + LEN_WIKI_OPEN_METADATA); if(nestedOpenTagIndex >= 0) { processedLine.replace(openIndex, nestedOpenTagIndex, WIKI_FORMATTED + processedLine.substring(openIndex + LEN_WIKI_OPEN_METADATA, nestedOpenTagIndex) .replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' ')); fromIndex = openIndex; } else { processedLine.replace(openIndex, processedLine.length(), WIKI_FORMATTED + processedLine.substring(openIndex + LEN_WIKI_OPEN_METADATA).replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' ')); break; } } } /* Handle any eventual multi-line template remaining closing tags */ fromIndex = 0; while ((closeIndex = processedLine.indexOf(WIKI_CLOSE_METADATA, fromIndex)) >= 0) { processedLine.replace(fromIndex, closeIndex, processedLine.substring(fromIndex, closeIndex).replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' ')); processedLine.delete(closeIndex, closeIndex + LEN_WIKI_CLOSE_METADATA); fromIndex = closeIndex; } /* Handle any eventual multi-line template remaining parameter lines */ String result = processedLine.toString(); if(result.matches("^\\s*\\" + WIKI_METADATA_PARAMETER_SEPARATOR + "\\s*[^\\-\\}\\|].*")) { result = result.replace(WIKI_METADATA_PARAMETER_SEPARATOR, ' ').replace('=', ' '); } return result; } private class TableOfContent { private final List toc = new ArrayList(); // needs to be list which ensures order int size() { return this.toc.size(); } String get(final int index) { return this.toc.get(index); } synchronized boolean add(final String element) { return this.toc.add(element); } Iterator iterator() { return this.toc.iterator(); } void clear() { this.toc.clear(); } } }