[PDFBOX-1804] PDFTextStripper Issue related to word positions not correctly being parsed

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.3
• Fix Version/s: 1.8.4, 2.0.0
• Component/s: Text extraction
• Assignee: Andreas Lehmkühler
• Reporter: Andy Phillips
• Created: 09/Dec/13 14:44
• Updated: 31/Jan/14 06:46
• Resolved: 02/Jan/14 09:24

Description

I found in a PDF I was pulling text from by using a custom PDFTextStripper subclass that overrides writeString(String text, List<TextPosition> textPositions) that i was getting the wrong textPositions that were not lined up with the text. I found that the test position of all “words” in a line always come over as the “last” text positions of the last word in the line. I found the issue in the PDFTextStripper class

So here is the Code Issue:

/**

• Used within {@link #normalize(List, boolean, boolean)} to handle a {@link TextPosition}.
  * @return The StringBuilder that must be used when calling this method.
  */
  private StringBuilder normalizeAdd(LinkedList<WordWithTextPositions> normalized,
  StringBuilder lineBuilder, List<TextPosition> wordPositions, TextPosition text)
  {
  if (text instanceof WordSeparator)
  { normalized.add(createWord(lineBuilder.toString(), wordPositions)); lineBuilder = new StringBuilder(); wordPositions.clear(); }
  else
  { lineBuilder.append(text.getCharacter()); wordPositions.add(text); }
  return lineBuilder;
  }
  
  
  When the normalizeAdd method, you create a new word passing the wordPositions. A reference to the wordPositions is stored in the new WordWithTextPositions in the normalized linked list, but in the next line, you clear(). Since the last wordPositions was passed as a reference, the wordPositions is cleared in the WordWithTextPositions you just created.
  
  Soo, i would suggest you do the following:
  /**
  * Used within {@link #normalize(List, boolean, boolean)}

  to handle a

  {@link TextPosition}

  .

• @return The StringBuilder that must be used when calling this method.
  */
  private StringBuilder normalizeAdd(LinkedList<WordWithTextPositions> normalized,
  StringBuilder lineBuilder, List<TextPosition> wordPositions, TextPosition text)
  Unknown macro: { if (text instanceof WordSeparator) { normalized.add(createWord(lineBuilder.toString(), new ArrayList<TextPosition>(wordPositions))); lineBuilder = new StringBuilder(); wordPositions.clear(); } else { lineBuilder.append(text.getCharacter()); wordPositions.add(text); } return lineBuilder; }