pdf-as-lib maven project files moved to pdf-as-lib

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/pdf-as/trunk@926 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c

1 files changed, 0 insertions, 956 deletions

diff --git a/src/main/java/at/knowcenter/wag/egov/egiz/pdf/AbsoluteTextSignature.java b/src/main/java/at/knowcenter/wag/egov/egiz/pdf/AbsoluteTextSignature.java
deleted file mode 100644
index fd59d34..0000000
--- a/src/main/java/at/knowcenter/wag/egov/egiz/pdf/AbsoluteTextSignature.java
+++ /dev/null
@@ -1,956 +0,0 @@
-/**

- * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>

- * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a

- * joint initiative of the Federal Chancellery Austria and Graz University of

- * Technology.

- *

- * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by

- * the European Commission - subsequent versions of the EUPL (the "Licence");

- * You may not use this work except in compliance with the Licence.

- * You may obtain a copy of the Licence at:

- * http://www.osor.eu/eupl/

- *

- * Unless required by applicable law or agreed to in writing, software

- * distributed under the Licence is distributed on an "AS IS" basis,

- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

- * See the Licence for the specific language governing permissions and

- * limitations under the Licence.

- *

- * This product combines work with different licenses. See the "NOTICE" text

- * file for details on the various modules and licenses.

- * The "NOTICE" text file is part of the distribution. Any derivative works

- * that you distribute must include a readable copy of the "NOTICE" text file.

- *

- * $Id: AbsoluteTextSignature.java,v 1.1 2006/10/31 08:08:33 wprinz Exp $

- */

-package at.knowcenter.wag.egov.egiz.pdf;

-

-import java.util.ArrayList;

-import java.util.Collections;

-import java.util.Comparator;

-import java.util.Iterator;

-import java.util.List;

-import java.util.Vector;

-

-import org.apache.log4j.Logger;

-

-import at.knowcenter.wag.egov.egiz.PdfAS;

-import at.knowcenter.wag.egov.egiz.cfg.ConfigLogger;

-import at.knowcenter.wag.egov.egiz.exceptions.SignatureException;

-import at.knowcenter.wag.egov.egiz.exceptions.SignatureTypesException;

-import at.knowcenter.wag.egov.egiz.framework.FoundBlock;

-import at.knowcenter.wag.egov.egiz.framework.FoundKey;

-import at.knowcenter.wag.egov.egiz.sig.SignatureObject;

-import at.knowcenter.wag.egov.egiz.sig.SignatureTypeDefinition;

-import at.knowcenter.wag.egov.egiz.sig.SignatureTypes;

-

-/**

- * Contains methods and helpers that implement the absolute text signature.

- * 

- * @author wprinz

- */

-public class AbsoluteTextSignature

-{

-

-  /**

-   * The logger definition.

-   */

-  private static final Logger logger = ConfigLogger.getLogger(AbsoluteTextSignature.class);

-

-  /**

-   * Returns a List of SignatureTypeDefinitions that can be extracted from text.

-   * 

-   * <p>

-   * These SignatureTypeDefinitions are all text extractable, which means that they define all required fields as visible.

-   * </p>

-   * <p>

-   * This method filters out all SignatureTypeDefinitions that are not text extractable.

-   * </p>

-   * 

-   * @return Returns a List of SignatureTypeDefinitions that can be extracted from text.

-   * @throws SignatureTypesException F.e.

-   */

-  public static List getSignatureTypesForTextAnalysis() throws SignatureTypesException

-  {

-    SignatureTypes sig_types = SignatureTypes.getInstance();

-    List allSignatureTypes = sig_types.getSignatureTypeDefinitions();

-    

-    List textSignatureTypes = new ArrayList(allSignatureTypes.size());

-    Iterator it = allSignatureTypes.iterator();

-    while (it.hasNext())

-    {

-      SignatureTypeDefinition std = (SignatureTypeDefinition) it.next();

-      if (!std.isTextExtractable())

-      {

-        logger.debug("The profile " + std.getType() + " is not text extractable and is thereby not used for text analysis.");

-        continue;

-      }

-      textSignatureTypes.add(std);

-    }

-

-    return textSignatureTypes;

-  }

-  

-  /**

-   * Extracts all signature holders from a given text.

-   * 

-   * <p>

-   * First the latest signature holder is extracted. Then the latest signature

-   * holder in the rest text, which is the second latest one, is extracted. Then

-   * the third latest signature holder is extracted and so forth until no more

-   * signature holders are found.

-   * </p>

-   * 

-   * @param text

-   *          The text.

-   * @return Returns the List of extracted signature holders ordered by their

-   *         date ascendingly (the lowest, earliest date first, the latest,

-   *         newest date last). An empty list is returned if no signature

-   *         holders were found.

-   * @throws SignatureException

-   *           F.e.

-   * @throws SignatureTypesException

-   *           F.e.

-   */

-  public static List extractSignatureHoldersFromText(String text) throws SignatureException, SignatureTypesException

-  {

-    List holders = new ArrayList();

-    String current_text = text;

-    for (;;)

-    {

-      TextualSignatureHolder signature_holder = extractLatestBlock(current_text);

-      if (signature_holder == null)

-      {

-        break;

-      }

-      holders.add(0, signature_holder);

-      current_text = signature_holder.getSignedText();

-    }

-    return holders;

-  }

-

-  /**

-   * Extracts the latest signature block from the given text and creates a

-   * SignatureHolder object that can be verified.

-   * 

-   * @param text

-   *          The text.

-   * @return Returns the SignatureObject extracted from the text, or null, if no

-   *         latest block was found.

-   * @throws SignatureException

-   *           F.e.

-   * @throws SignatureTypesException

-   *           F.e.

-   */

-  public static TextualSignatureHolder extractLatestBlock(String text) throws SignatureException, SignatureTypesException

-  {

-    FoundBlock latest_block = findLatestBlock(text);

-    if (latest_block == null)

-    {

-      return null;

-    }

-    String reconstructed_text = cutOutBlock(text, latest_block);

-    SignatureObject so = createSignatureObjectFromFoundBlock(text, latest_block);

-    TextualSignatureHolder tsh = new TextualSignatureHolder(reconstructed_text, so);

-    return tsh;

-  }

-

-  /**

-   * Finds the latest signature block for a given text.

-   * 

-   * <p>

-   * The latest block is the one with the highest, most recent date. Usually

-   * this block will be extracted (cut out) of the text which will result in the

-   * originally signed text of this signature to be verified using the cut out

-   * data.

-   * </p>

-   * 

-   * @param text

-   *          The text to be analyzed.

-   * @return Returns the latest found block or null, if there was none.

-   * @throws SignatureException

-   *           F.e.

-   * @throws SignatureTypesException

-   *           F.e.

-   */

-  public static FoundBlock findLatestBlock(String text) throws SignatureException, SignatureTypesException

-  {

-    List signatureTypes_ = getSignatureTypesForTextAnalysis();

-    

-    List found_potential_candidates = new ArrayList();

- 

-    for (int i = 0; i < signatureTypes_.size(); i++)

-    {

-      SignatureTypeDefinition block_type = (SignatureTypeDefinition) signatureTypes_.get(i);

-      List found_candidates_for_type = findPotentialSignaturesForProfile(text, block_type);

-

-      found_potential_candidates.addAll(found_candidates_for_type);

-    }

-

-    if (found_potential_candidates.isEmpty())

-    {

-      logger.debug("no candidates found at all");

-      return null;

-    }

-

-    List found_candidates = new ArrayList();

-    logger.debug("checking block integrity");

-    for (int i = 0; i < found_potential_candidates.size(); i++)

-    {

-      FoundBlock found_block = (FoundBlock) found_potential_candidates.get(i);

-      String date_value = getDateValue(text, found_block);

-      try

-      {

-        EGIZDate date = EGIZDate.parseFromString(date_value);

-

-        logger.debug("found_block = " + date + " - " + found_block);

-

-        checkBlockIntegrity(text, found_block);

-        found_candidates.add(found_block);

-      }

-      catch (Exception e)

-      {

-        logger.debug("Exception while checking the integrity of the found block " + found_block + ". Ignoring this block.", e);

-      }

-    }

-

-    sortFoundBlocksByDate(text, found_candidates);

-    if (logger.isDebugEnabled())

-    {

-      logger.debug("sorted blocks:");

-      for (int i = 0; i < found_candidates.size(); i++)

-      {

-        FoundBlock found_block = (FoundBlock) found_candidates.get(i);

-

-        String date_value = getDateValue(text, found_block);

-        EGIZDate date = EGIZDate.parseFromString(date_value);

-

-        logger.debug("  #" + i + ": " + date + " - " + found_block);

-      }

-    }

-

-    List latest_blocks = filterLastDateEqualBlocks(text, found_candidates);

-    if (logger.isDebugEnabled())

-    {

-      logger.debug("latest blocks:");

-      for (int i = 0; i < latest_blocks.size(); i++)

-      {

-        FoundBlock found_block = (FoundBlock) latest_blocks.get(i);

-

-        String date_value = getDateValue(text, found_block);

-        EGIZDate date = EGIZDate.parseFromString(date_value);

-

-        logger.debug("  #" + i + ": " + date + " - " + found_block);

-      }

-    }

-

-    // The semantic equality check has been outdated by the

-    // advanced choosing algorithm.

-    // boolean semantic_equality =

-    // PdfAS.checkForSemanticEquality(latest_blocks);

-    // logger.debug("semantic_equality = " + semantic_equality);

-    // if (!semantic_equality)

-    // {

-    // throw new SignatureException(314, "The latest blocks weren't semantically

-    // equal.");

-    // }

-

-    FoundBlock latest_block = chooseMostPossibleBlock(latest_blocks);

-

-    logger.debug("latest block = " + latest_block);

-    return latest_block;

-  }

-

-  /**

-   * Finds the List of potential blocks within the given text for the given

-   * profile.

-   * 

-   * @param text

-   *          The text, in which potential block are to be sought.

-   * @param block_type

-   *          The profile for which the text is to be sought.

-   * @return Returns the List of potential FoundBlocks or an empty List if none

-   *         could be found.

-   */

-  public static List findPotentialSignaturesForProfile(String text,

-      SignatureTypeDefinition block_type)

-  {

-    logger.debug("find potential signatures for " + block_type.getType());

-    List found_blocks = new ArrayList();

-

-    final boolean old_style = false;

-

-    Vector keys = block_type.getRevertSortedKeys();

-    Vector captions = block_type.getRevertSortedCaptions();

-

-    String last_key = (String) keys.get(0);

-    logger.debug("last_key = " + last_key);

-    String last_caption = (String) captions.get(0);

-    logger.debug("last_caption = " + last_caption);

-    String current_last_caption= last_caption;

-    List found_last_captions = findIndicesWithStartingNL(text, last_caption);

-    if (last_key.equals(SignatureTypes.SIG_ID))

-    {

-      logger.debug("Last key is SIG_ID, so it may not be present. Searching for the previous to last key.");

-      String prevlast_key = (String) keys.get(1);

-      String prevlast_caption = (String) captions.get(1);

-      current_last_caption = prevlast_caption; 

-      List found_prevlast_captions = findIndicesWithStartingNL(text, prevlast_caption);

-      if (!found_prevlast_captions.isEmpty())

-      {

-        found_last_captions.addAll(found_prevlast_captions);

-      }

-    }

-    if (logger.isDebugEnabled())

-    {

-      logger.debug("found " + found_last_captions.size() + " last captions.");

-      for (int i = 0; i < found_last_captions.size(); i++)

-      {

-        logger.debug("  found last caption at index " + found_last_captions.get(i));

-      }

-    }

-

-    for (int lci = 0; lci < found_last_captions.size(); lci++)

-    {

-      int last_caption_index = ((Integer) found_last_captions.get(lci)).intValue();

-      logger.debug("resolving signature block from last caption index " + last_caption_index);

-      int potential_block_end = findEndOfValue(text, last_caption_index);

-      if (potential_block_end == (last_caption_index + current_last_caption.length()+1))

-      {

-    	  potential_block_end = findEndOfValue(text, potential_block_end);

-      }

-      

-      // FIXME: complete HOTFIX

-      /*

-      int extendedValueEnd = potential_block_end;

-      String cv;

-      do {

-         extendedValueEnd = findEndOfValue(text, extendedValueEnd);

-         cv = text.substring(last_caption_index + current_last_caption.length()+1, extendedValueEnd);

-      } while (extendedValueEnd < text.length());

-      */

-      

-      logger.debug("potential_block_end = " + potential_block_end);

-      List found_keys = PdfAS.findBlockInText(text.substring(0, potential_block_end), block_type, old_style); // findRestKeys(text,

-      // keys,

-      // captions,

-      // last_caption_index);

-

-      if (found_keys == null)

-      {

-        logger.debug("Not all other captions could be found for the last_caption_index " + last_caption_index + " ==> discarding this index.");

-

-        continue;

-      }

-

-      // sort found keys ascendingly

-      PdfAS.sortFoundKeysAscendingly(found_keys);

-

-      boolean reverse_check_ok = reverseCheckFoundKeys(text, found_keys);

-      if (!reverse_check_ok)

-      {

-        logger.debug("The reverse check ruled this list of found keys out ==> they are discarded.");

-

-        continue;

-      }

-

-      logger.debug("The reverse check proved this list of found keys out ==> adding them as potential candidates.");

-

-      FoundBlock found_block = new FoundBlock();

-      found_block.std = block_type;

-      found_block.found_keys = found_keys;

-      found_block.end_index = potential_block_end;//findEndOfValue(text, last_caption_index);

-      found_blocks.add(found_block);

-    }

-

-    logger.debug("found " + found_blocks.size() + " potential signatures for " + block_type.getType());

-    return found_blocks;

-  }

-

-  /**

-   * Finds all indices of the given subtext (starting at a new line) within a

-   * given text.

-   * 

-   * <p>

-   * This is usually used to find the indices of the last captions.

-   * </p>

-   * 

-   * @param text

-   *          The text to be searched.

-   * @param subtext

-   *          The subtext to be sought.

-   * @return Returns the List of found indices.

-   */

-  public static List findIndicesWithStartingNL(String text, String subtext)

-  {

-    List found_indices = new ArrayList();

-

-    // // for some reason "^" + subtext doesn't work as a pattern

-    // String pattern = "\n" + subtext;

-    // Pattern p = Pattern.compile(pattern);

-    // Matcher m = p.matcher(text);

-    //    

-    // while (m.find())

-    // {

-    // int found_index = m.start() + 1; // +1 removes the newline

-    // found_indices.add(new Integer(found_index));

-    // }

-

-    int search_from_index = 0;

-    for (;;)

-    {

-      int found_index = text.indexOf("\n" + subtext, search_from_index);

-      if (found_index < 0)

-      {

-        break;

-      }

-      found_index += 1; // The +1 compensates the "\n"

-      found_indices.add(new Integer(found_index));

-      search_from_index = found_index + subtext.length();

-    }

-    return found_indices;

-  }

-

-  /**

-   * Finds the other keys/captions according to their order starting from the

-   * last_caption index upwards.

-   * 

-   * @param text

-   *          The text.

-   * @param keys

-   *          The list of keys.

-   * @param captions

-   *          The list of captions.

-   * @param last_caption_index

-   *          The index of the last caption.

-   * @return Returns the List of found keys, if all keys could be found, or null

-   *         if not all keys could be found.

-   */

-  public static List findRestKeys(String text, List keys, List captions,

-      int last_caption_index)

-  {

-    List found_keys = new ArrayList();

-

-    FoundKey last_caption_found_key = new FoundKey((String) keys.get(0), (String) captions.get(0), last_caption_index);

-    found_keys.add(last_caption_found_key);

-

-    String rest_text = text.substring(0, last_caption_index);

-

-    for (int i = 1; i < captions.size(); i++)

-    {

-      String sought_caption = (String) captions.get(i);

-      int index = rest_text.lastIndexOf(sought_caption);

-

-      if (index < 0)

-      {

-        return null;

-      }

-      FoundKey found_key = new FoundKey((String) keys.get(i), (String) captions.get(i), index);

-      found_keys.add(0, found_key);

-

-      rest_text = rest_text.substring(0, index);

-    }

-

-    return found_keys;

-  }

-

-  /**

-   * Performs a reverse (top to bottom) search for the found keys and checks

-   * that these indices are the same as those that were found during the regular

-   * (bottom up) search.

-   * <p>

-   * If a reverse check proves that the found keys are not at the same positions

-   * as during regular search, this list of found keys should be discarded.

-   * </p>

-   * 

-   * @param text

-   *          The text.

-   * @param found_keys

-   *          The found keys to be reversely checked.

-   * @return Returns true, if all (also the non required) captions could be

-   *         found at the same indices as during regular search, false

-   *         otherwise.

-   */

-  public static boolean reverseCheckFoundKeys(String text, List found_keys)

-  {

-    int search_from_index = ((FoundKey) found_keys.get(0)).start_index;

-    for (int i = 0; i < found_keys.size(); i++)

-    {

-      FoundKey found_key = (FoundKey) found_keys.get(i);

-

-      int reverse_found_index = text.indexOf(found_key.caption, search_from_index);

-      

-      // dferbas fix #331 ??

-      

-      if (reverse_found_index < 0)

-      {

-        throw new RuntimeException("The caption " + found_key.caption + " wasn't found in the text during reverse checking - there is something wrong.");

-      }

-      

-      if (reverse_found_index != found_key.start_index)

-      {

-        logger.debug("The index for caption " + found_key.caption + " wasn't proved during reverse checking.");

-        return false;

-      }

-      search_from_index = found_key.start_index + found_key.caption.length();

-    }

-    return true;

-  }

-

-  /**

-   * Finds the end of the value in the text.

-   * 

-   * <p>

-   * This simply scans for a '\n' from a given start index. The line up to and

-   * inclusive the '\n' is considered to be the value.

-   * </p>

-   * <p>

-   * Note that this method does NOT find the accurate value, if the value goes

-   * over multiple lines! This may bear a serious problem. Usually this method

-   * is only used to finding the end of the last value in a found block, because

-   * mid- values are exactly determined by their start index and the start of

-   * the next caption. Nevertheless, if the last value spans over multiple

-   * lines, this method will not retrieve it completely.

-   * </p>

-   * 

-   * @param text

-   *          The text.

-   * @param start_index

-   *          The start index from where the end of the value is sought.

-   * @return Returns the end index of the value, which is the index of the first

-   *         character not belonging to the value anymore (the character after

-   *         the '\n').

-   */

-  public static int findEndOfValue(String text, int start_index)

-  {

-    int newline_index = text.indexOf('\n', start_index);

-    if (newline_index < 0)

-    {

-      return text.length();

-    }   

-    return newline_index + 1;

-  }

- 

-  /**

-   * Checks the integrity of a found block.

-   * 

-   * <p>

-   * This is an assertive function.

-   * </p>

-   * 

-   * @param text

-   *          The text.

-   * @param found_block

-   *          The found block.

-   */

-  public static void checkBlockIntegrity(String text, FoundBlock found_block)

-  {

-    for (int i = 0; i < found_block.found_keys.size() - 1; i++)

-    {

-      FoundKey this_key = (FoundKey) found_block.found_keys.get(i);

-      FoundKey next_key = (FoundKey) found_block.found_keys.get(i + 1);

-

-      int this_end_index = findEndOfValue(text, this_key.start_index);

-      if (this_end_index != next_key.start_index)

-      {

-        logger.debug("multi line value: " + this_key);

-        // throw new RuntimeException("The end index of found key " + this_key +

-        // " doesn't match the start index of found key " + next_key);

-      }

-    }

-

-    FoundKey last_key = (FoundKey) found_block.found_keys.get(found_block.found_keys.size() - 1);

-    int end_of_block =  findEndOfValue(text, last_key.start_index);

-    if (end_of_block == (last_key.start_index+last_key.caption.length()+1))

-    {

-    	end_of_block = findEndOfValue(text,end_of_block);

-    }

-    if (end_of_block != found_block.end_index)

-    {

-        throw new RuntimeException("The end index of last key " + last_key + " doesn't match the end index of the block " + found_block);

-    }

-  }

-

-  /**

-   * Cuts out the given found block from the text.

-   * 

-   * @param text

-   *          The text.

-   * @param block

-   *          The found block.

-   * @return Returns the rest text without the block.

-   */

-  public static String cutOutBlock(String text, FoundBlock block)

-  {

-    int block_start_index = ((FoundKey) block.found_keys.get(0)).getStartIndex();

-    int block_end_index = block.end_index;

-    

-    if (block_start_index == 0 && block_end_index == text.length())

-    {

-      // the block is the whole text - the rest text is empty.

-      // This may happen if a (no-text) empty document contains a binary signature.

-      // Then the "signed text" of the binary signature is empty.

-      return "";

-    }

-

-    if (block_end_index == text.length())

-    {

-      // if the block is at the end of the text, remove the "\n" before the

-      // block as well.

-      String pre = text.substring(0, block_start_index - 1);

-      return pre;

-    }

-

-    String pre = text.substring(0, block_start_index);

-    String post = text.substring(block_end_index);

-

-    String rest_text = pre + post;

-    return rest_text;

-  }

-

-  /**

-   * Returns the value of the date field as String.

-   * 

-   * @param text

-   *          The text.

-   * @param block

-   *          The found block.

-   * @return Returns the date value.

-   */

-  public static String getDateValue(String text, FoundBlock block)

-  {

-    FoundKey date_key = block.getDateFoundKey();

-    int date_value_start_index = date_key.start_index + date_key.caption.length();

-    int date_value_end_index = findEndOfValue(text, date_value_start_index);

-    if (date_value_end_index == (date_value_start_index+1))

-    {

-    	date_value_end_index = findEndOfValue(text, date_value_end_index);	

-    }

-    String date_value = text.substring(date_value_start_index, date_value_end_index).trim();

-    logger.debug("DateString="+date_value);

-    return date_value;

-  }

-

-  /**

-   * Creates a SignatureObject from a found block by extracting the

-   * corresponding values.

-   * 

-   * @param text

-   *          The text.

-   * @param found_block

-   *          The found block.

-   * @return Returns the created SignatureObject.

-   * @throws SignatureTypesException

-   *           F.e.

-   * @throws SignatureException

-   *           F.e.

-   */

-  public static SignatureObject createSignatureObjectFromFoundBlock(

-      String text, FoundBlock found_block) throws SignatureTypesException, SignatureException

-  {

-    SignatureObject signatureObject = new SignatureObject();

-

-    signatureObject.setSigType(found_block.std.getType());

-    signatureObject.initByType();

-

-    int end_index = found_block.end_index;

-    for (int i = found_block.found_keys.size() - 1; i >= 0; i--)

-    {

-      FoundKey cur_key = (FoundKey) found_block.found_keys.get(i);

-      int start_index = cur_key.getStartIndex() + cur_key.caption.length();

-

-      String value = text.substring(start_index, end_index);

-

-      signatureObject.setSigValueCaption(cur_key.getKey(), value, cur_key.caption);

-

-      end_index = cur_key.getStartIndex();

-    }

-

-    return signatureObject;

-

-  }

-

-  /**

-   * Parses the EGIZDate from a found block and the given text.

-   * 

-   * @param text

-   *          The text.

-   * @param found_block

-   *          The found block.

-   * @return Returns the parsed EGIZDate.

-   */

-  public static EGIZDate getDateFromFoundBlock(String text,

-      FoundBlock found_block)

-  {

-    String date_value = getDateValue(text, found_block);

-    EGIZDate date = EGIZDate.parseFromString(date_value);

-    return date;

-  }

-

-  /**

-   * Sorts the List of found blocks by date.

-   * 

-   * @param text

-   *          The text.

-   * @param found_blocks

-   *          The List of found blocks.

-   */

-  public static void sortFoundBlocksByDate(final String text, List found_blocks)

-  {

-    Collections.sort(found_blocks, new Comparator()

-    {

-      public int compare(Object arg0, Object arg1)

-      {

-        FoundBlock fb0 = (FoundBlock) arg0;

-        FoundBlock fb1 = (FoundBlock) arg1;

-

-        EGIZDate date0 = getDateFromFoundBlock(text, fb0);

-        EGIZDate date1 = getDateFromFoundBlock(text, fb1);

-        return date0.compareTo(date1);

-      }

-    });

-  }

-

-  /**

-   * Given a List of FoundBlock objects, this method returns the last blocks of

-   * this list that have the same date.

-   * 

-   * <p>

-   * Usually a date sorted list (earliest first, latest last) will be provided

-   * to this method. Then the last date equal blocks are returned, which are the

-   * last blocks.

-   * </p>

-   * 

-   * @param text

-   *          The text to retrieve the values of the fields from.

-   * @param found_blocks

-   *          The List of FoundBlock objects.

-   * @return Returns the List of the last date equal blocks.

-   */

-  public static List filterLastDateEqualBlocks(String text, List found_blocks)

-  {

-    List latest_blocks = new ArrayList();

-    latest_blocks.add(found_blocks.get(found_blocks.size() - 1));

-    for (int i = found_blocks.size() - 2; i >= 0; i--)

-    {

-      FoundBlock this_block = (FoundBlock) found_blocks.get(i);

-      FoundBlock succ_block = (FoundBlock) found_blocks.get(i + 1);

-

-      EGIZDate this_date = getDateFromFoundBlock(text, this_block);

-      EGIZDate succ_date = getDateFromFoundBlock(text, succ_block);

-

-      if (!this_date.equals(succ_date))

-      {

-        break;

-      }

-      latest_blocks.add(0, this_block);

-    }

-

-    return latest_blocks;

-  }

-  /**

-   * Chooses the most possible (best choice) block of the list of blocks.

-   * 

-   * <p>

-   * The strategy to find the most possible block is to choose the very one

-   * block with the maximum number of captions. This block has extracted most

-   * information from the text.

-   * </p>

-   * <p>

-   * If there are still multiple blocks with the same number of cations, the

-   * blocks are compared caption-wise. The block with all captions being longer

-   * or equal to all other blocks' captions wins.

-   * </p>

-   * 

-   * @param found_blocks

-   *          The List of semantically equal blocks.

-   * @return Returns the best choice FoundBlock.

-   * @throws SignatureException

-   */

-  public static FoundBlock chooseMostPossibleBlock(List found_blocks) throws SignatureException

-  {

-    // int largest_block_index = 0;

-    // FoundBlock largest_block = (FoundBlock) found_blocks.get(0);

-    //

-    // for (int i = 1; i < found_blocks.size(); i++)

-    // {

-    // FoundBlock current_block = (FoundBlock) found_blocks.get(i);

-    //

-    // if (current_block.found_keys.size() > largest_block.found_keys.size())

-    // {

-    // largest_block = current_block;

-    // largest_block_index = i;

-    // }

-    // }

-

-    List vertically_largest = filterVerticallyLargestBlocks(found_blocks);

-    if (logger.isDebugEnabled())

-    {

-      logger.debug("vertically largest blocks:");

-      for (int i = 0; i < vertically_largest.size(); i++)

-      {

-        FoundBlock found_block = (FoundBlock) vertically_largest.get(i);

-        logger.debug("  #" + i + ": " + found_block);

-      }

-    }

-

-    List horizontally_largest = filterHorizontallyLargestBlocks(vertically_largest);

-    if (logger.isDebugEnabled())

-    {

-      logger.debug("horizontally largest blocks:");

-      for (int i = 0; i < horizontally_largest.size(); i++)

-      {

-        FoundBlock found_block = (FoundBlock) horizontally_largest.get(i);

-        logger.debug("  #" + i + ": " + found_block);

-      }

-    }

-    FoundBlock largest_block = (FoundBlock) horizontally_largest.get(0);

-    logger.debug("Chose largest block: " + largest_block);

-    return largest_block;

-  }

-

-  /**

-   * Filters out all blocks but the vertically largest ones.

-   * 

-   * <p>

-   * A vertically largest block has the most found keys.

-   * </p>

-   * 

-   * @param found_blocks

-   *          The List of FoundBlock objects to be filtered.

-   * @return Returns the List of the vertically largest FoundBlock objects.

-   */

-  public static List filterVerticallyLargestBlocks(List found_blocks)

-  {

-    // determine the size of the largest block(s)

-    int largest_size = Integer.MIN_VALUE;

-    for (int i = 0; i < found_blocks.size(); i++)

-    {

-      FoundBlock fb = (FoundBlock) found_blocks.get(i);

-      final int current_size = fb.found_keys.size();

-      if (current_size > largest_size)

-      {

-        largest_size = current_size;

-      }

-    }

-

-    // keep all blocks that have the largest_size

-    List largest_blocks = new ArrayList();

-    for (int i = 0; i < found_blocks.size(); i++)

-    {

-      FoundBlock fb = (FoundBlock) found_blocks.get(i);

-      if (fb.found_keys.size() < largest_size)

-      {

-        continue;

-      }

-      largest_blocks.add(fb);

-    }

-    return largest_blocks;

-  }

-

-  /**

-   * Filters out all blocks but the horizonally largest ones.

-   * 

-   * <p>

-   * A vertically largest block has the most found keys.

-   * </p>

-   * 

-   * @param found_blocks

-   *          The List of FoundBlock objects to be filtered. All of these

-   *          FoundBlock objects must have the same number of found keys.

-   * @return Returns the List of the horizontally largest FoundBlock objects.

-   * @throws SignatureException

-   */

-  public static List filterHorizontallyLargestBlocks(List found_blocks) throws SignatureException

-  {

-    List horizontally_largest = new ArrayList();

-    FoundBlock largest_block = (FoundBlock) found_blocks.get(0);

-    horizontally_largest.add(largest_block);

-

-    for (int i = 1; i < found_blocks.size(); i++)

-    {

-      FoundBlock fb = (FoundBlock) found_blocks.get(i);

-

-      if (isHorizontallyEqual(fb, largest_block))

-      {

-        horizontally_largest.add(fb);

-        continue;

-      }

-

-      if (isHorizontallyLarger(fb, largest_block))

-      {

-        horizontally_largest = new ArrayList();

-        largest_block = fb;

-        horizontally_largest.add(largest_block);

-      }

-      else

-      {

-        if (!isHorizontallyLarger(largest_block, fb))

-        {

-          // The block is neither equal nor larger nor lower.

-          // We cannot exactly determine which one to use.

-          throw new SignatureException(315, "The blocks are neither larger nor lower nor equal. Cannot decide which one to pick. fb = " + fb + ", largest_block = " + largest_block);

-        }

-      }

-

-    }

-

-    return horizontally_largest;

-  }

-

-  protected static boolean isHorizontallyEqual(FoundBlock fb0, FoundBlock fb1)

-  {

-    final int num_keys = fb0.found_keys.size();

-    if (num_keys != fb1.found_keys.size())

-    {

-      throw new IllegalArgumentException("Cannot compare FoundBlock keys: fb0 doesn't have the same number of keys as fb1. " + fb0.found_keys.size() + " vs. " + fb1.found_keys.size());

-    }

-

-    for (int i = 0; i < num_keys; i++)

-    {

-      FoundKey fk0 = (FoundKey) fb0.found_keys.get(i);

-      FoundKey fk1 = (FoundKey) fb1.found_keys.get(i);

-

-      if (fk0.caption.length() != fk1.caption.length())

-      {

-        return false;

-      }

-    }

-

-    return true;

-  }

-

-  protected static boolean isHorizontallyLarger(FoundBlock fb0, FoundBlock fb1)

-  {

-    final int num_keys = fb0.found_keys.size();

-    if (num_keys != fb1.found_keys.size())

-    {

-      throw new IllegalArgumentException("Cannot compare FoundBlock keys: fb0 doesn't have the same number of keys as fb1. " + fb0.found_keys.size() + " vs. " + fb1.found_keys.size());

-    }

-

-    boolean larger = false;

-

-    for (int i = 0; i < num_keys; i++)

-    {

-      FoundKey fk0 = (FoundKey) fb0.found_keys.get(i);

-      FoundKey fk1 = (FoundKey) fb1.found_keys.get(i);

-

-      if (fk0.caption.length() == fk1.caption.length())

-      {

-        continue;

-      }

-

-      if (fk0.caption.length() > fk1.caption.length())

-      {

-        larger = true;

-        continue;

-      }

-

-      // if (fk0.caption.length() < fk1.caption.length())

-      return false;

-    }

-

-    return larger;

-  }

-

-}