org.apache.pdfbox.util.PDFTextStripper Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of pdfbox Show documentation
Show all versions of pdfbox Show documentation
The Apache PDFBox library is an open source Java tool for working with PDF documents.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.pdfbox.util;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.Vector;
import java.util.regex.Pattern;
import org.apache.pdfbox.cos.COSDocument;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.COSObjectable;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.common.PDStream;
import org.apache.pdfbox.pdmodel.interactive.documentnavigation.outline.PDOutlineItem;
import org.apache.pdfbox.pdmodel.interactive.pagenavigation.PDThreadBead;
/**
* This class will take a pdf document and strip out all of the text and ignore the
* formatting and such. Please note; it is up to clients of this class to verify that
* a specific user has the correct permissions to extract text from the
* PDF document.
*
* The basic flow of this process is that we get a document and use a series of
* processXXX() functions that work on smaller and smaller chunks of the page.
* Eventually, we fully process each page and then print it.
*
* @author Ben Litchfield
*
*/
public class PDFTextStripper extends PDFStreamEngine
{
private static final String thisClassName = PDFTextStripper.class.getSimpleName().toLowerCase();
private static float DEFAULT_INDENT_THRESHOLD = 2.0f;
private static float DEFAULT_DROP_THRESHOLD = 2.5f;
private static final boolean useCustomQuicksort;
//enable the ability to set the default indent/drop thresholds
//with -D system properties:
// pdftextstripper.indent
// pdftextstripper.drop
static
{
String sdrop = null, sindent = null;
try
{
String prop = thisClassName + ".indent";
sindent = System.getProperty(prop);
prop = thisClassName + ".drop";
sdrop = System.getProperty(prop);
}
catch (SecurityException e)
{
// PDFBOX-1946 when run in an applet
// ignore and use default
}
if (sindent != null && sindent.length() > 0)
{
try
{
float f = Float.parseFloat(sindent);
DEFAULT_INDENT_THRESHOLD = f;
}
catch (NumberFormatException nfe)
{
//ignore and use default
}
}
if (sdrop != null && sdrop.length() > 0)
{
try
{
float f = Float.parseFloat(sdrop);
DEFAULT_DROP_THRESHOLD = f;
}
catch (NumberFormatException nfe)
{
//ignore and use default
}
}
// check if we need to use the custom quicksort algorithm as a
// workaround to the transitivity issue of TextPositionComparator:
// https://issues.apache.org/jira/browse/PDFBOX-1512
boolean is16orLess = false;
try
{
String version = System.getProperty("java.specification.version");
StringTokenizer st = new StringTokenizer(version, ".");
int majorVersion = Integer.parseInt(st.nextToken());
int minorVersion = 0;
if (st.hasMoreTokens())
{
minorVersion = Integer.parseInt(st.nextToken());
}
is16orLess = majorVersion == 1 && minorVersion <= 6;
}
catch (SecurityException e)
{
// when run in an applet ignore and use default
// assume 1.7 or higher so that quicksort is used
}
catch (NumberFormatException nfe)
{
// should never happen, but if it does,
// assume 1.7 or higher so that quicksort is used
}
useCustomQuicksort = !is16orLess;
}
/**
* The platforms line separator.
*/
protected final String systemLineSeparator = System.getProperty("line.separator");
private String lineSeparator = systemLineSeparator;
private String pageSeparator = systemLineSeparator;
private String wordSeparator = " ";
private String paragraphStart = "";
private String paragraphEnd = "";
private String pageStart = "";
private String pageEnd = pageSeparator;
private String articleStart = "";
private String articleEnd = "";
private int currentPageNo = 0;
private int startPage = 1;
private int endPage = Integer.MAX_VALUE;
private PDOutlineItem startBookmark = null;
private int startBookmarkPageNumber = -1;
private PDOutlineItem endBookmark = null;
private int endBookmarkPageNumber = -1;
private boolean suppressDuplicateOverlappingText = true;
private boolean shouldSeparateByBeads = true;
private boolean sortByPosition = false;
private boolean addMoreFormatting = false;
private float indentThreshold = DEFAULT_INDENT_THRESHOLD;
private float dropThreshold = DEFAULT_DROP_THRESHOLD;
// We will need to estimate where to add spaces.
// These are used to help guess.
private float spacingTolerance = .5f;
private float averageCharTolerance = .3f;
private List beadRectangles = null;
/**
* The charactersByArticle is used to extract text by article divisions. For example
* a PDF that has two columns like a newspaper, we want to extract the first column and
* then the second column. In this example the PDF would have 2 beads(or articles), one for
* each column. The size of the charactersByArticle would be 5, because not all text on the
* screen will fall into one of the articles. The five divisions are shown below
*
* Text before first article
* first article text
* text between first article and second article
* second article text
* text after second article
*
* Most PDFs won't have any beads, so charactersByArticle will contain a single entry.
*/
protected Vector> charactersByArticle = new Vector>();
private Map>> characterListMapping =
new HashMap>>();
/**
* encoding that text will be written in (or null).
*/
protected String outputEncoding;
/**
* The document to read.
*/
protected PDDocument document;
/**
* The stream to write the output to.
*/
protected Writer output;
/**
* The normalizer is used to remove text ligatures/presentation forms
* and to correct the direction of right to left text, such as Arabic and Hebrew.
*/
private TextNormalize normalize = null;
/**
* True if we started a paragraph but haven't ended it
* yet.
*/
private boolean inParagraph;
/**
* Instantiate a new PDFTextStripper object. This object will load
* properties from PDFTextStripper.properties and will not do
* anything special to convert the text to a more encoding-specific
* output.
*
* @throws IOException If there is an error loading the properties.
*/
public PDFTextStripper() throws IOException
{
super( ResourceLoader.loadProperties(
"org/apache/pdfbox/resources/PDFTextStripper.properties", true ) );
this.outputEncoding = null;
normalize = new TextNormalize(this.outputEncoding);
}
/**
* Instantiate a new PDFTextStripper object. Loading all of the operator mappings
* from the properties object that is passed in. Does not convert the text
* to more encoding-specific output.
*
* @param props The properties containing the mapping of operators to PDFOperator
* classes.
*
* @throws IOException If there is an error reading the properties.
*/
public PDFTextStripper( Properties props ) throws IOException
{
super( props );
this.outputEncoding = null;
normalize = new TextNormalize(this.outputEncoding);
}
/**
* Instantiate a new PDFTextStripper object. This object will load
* properties from PDFTextStripper.properties and will apply
* encoding-specific conversions to the output text.
*
* @param encoding The encoding that the output will be written in.
* @throws IOException If there is an error reading the properties.
*/
public PDFTextStripper( String encoding ) throws IOException
{
super( ResourceLoader.loadProperties(
"org/apache/pdfbox/resources/PDFTextStripper.properties", true ));
this.outputEncoding = encoding;
normalize = new TextNormalize(this.outputEncoding);
}
/**
* This will return the text of a document. See writeText.
* NOTE: The document must not be encrypted when coming into this method.
*
* @param doc The document to get the text from.
* @return The text of the PDF document.
* @throws IOException if the doc state is invalid or it is encrypted.
*/
public String getText( PDDocument doc ) throws IOException
{
StringWriter outputStream = new StringWriter();
writeText( doc, outputStream );
return outputStream.toString();
}
/**
* @deprecated
* @see PDFTextStripper#getText( PDDocument )
* @param doc The document to extract the text from.
* @return The document text.
* @throws IOException If there is an error extracting the text.
*/
public String getText( COSDocument doc ) throws IOException
{
return getText( new PDDocument( doc ) );
}
/**
* @deprecated
* @see PDFTextStripper#writeText( PDDocument, Writer )
* @param doc The document to extract the text.
* @param outputStream The stream to write the text to.
* @throws IOException If there is an error extracting the text.
*/
public void writeText( COSDocument doc, Writer outputStream ) throws IOException
{
writeText( new PDDocument( doc ), outputStream );
}
/**
* {@inheritDoc}
*/
public void resetEngine()
{
super.resetEngine();
currentPageNo = 0;
document = null;
if (charactersByArticle != null)
{
charactersByArticle.clear();
}
if (characterListMapping != null)
{
characterListMapping.clear();
}
}
/**
* This will take a PDDocument and write the text of that document to the print writer.
*
* @param doc The document to get the data from.
* @param outputStream The location to put the text.
*
* @throws IOException If the doc is in an invalid state.
*/
public void writeText( PDDocument doc, Writer outputStream ) throws IOException
{
resetEngine();
document = doc;
output = outputStream;
if (getAddMoreFormatting())
{
paragraphEnd = lineSeparator;
pageStart = lineSeparator;
articleStart = lineSeparator;
articleEnd = lineSeparator;
}
startDocument(document);
processPages( document.getDocumentCatalog().getAllPages() );
endDocument(document);
}
/**
* This will process all of the pages and the text that is in them.
*
* @param pages The pages object in the document.
*
* @throws IOException If there is an error parsing the text.
*/
protected void processPages( List pages ) throws IOException
{
if( startBookmark != null )
{
startBookmarkPageNumber = getPageNumber( startBookmark, pages );
}
if( endBookmark != null )
{
endBookmarkPageNumber = getPageNumber( endBookmark, pages );
}
if( startBookmarkPageNumber == -1 && startBookmark != null &&
endBookmarkPageNumber == -1 && endBookmark != null &&
startBookmark.getCOSObject() == endBookmark.getCOSObject() )
{
//this is a special case where both the start and end bookmark
//are the same but point to nothing. In this case
//we will not extract any text.
startBookmarkPageNumber = 0;
endBookmarkPageNumber = 0;
}
Iterator pageIter = pages.iterator();
while( pageIter.hasNext() )
{
PDPage nextPage = (PDPage)pageIter.next();
PDStream contentStream = nextPage.getContents();
currentPageNo++;
if( contentStream != null )
{
COSStream contents = contentStream.getStream();
processPage( nextPage, contents );
}
}
}
private int getPageNumber( PDOutlineItem bookmark, List allPages ) throws IOException
{
int pageNumber = -1;
PDPage page = bookmark.findDestinationPage( document );
if( page != null )
{
pageNumber = allPages.indexOf( page )+1;//use one based indexing
}
return pageNumber;
}
/**
* This method is available for subclasses of this class. It will be called before processing
* of the document start.
*
* @param pdf The PDF document that is being processed.
* @throws IOException If an IO error occurs.
*/
protected void startDocument(PDDocument pdf) throws IOException
{
// no default implementation, but available for subclasses
}
/**
* This method is available for subclasses of this class. It will be called after processing
* of the document finishes.
*
* @param pdf The PDF document that is being processed.
* @throws IOException If an IO error occurs.
*/
protected void endDocument(PDDocument pdf ) throws IOException
{
// no default implementation, but available for subclasses
}
/**
* This will process the contents of a page.
*
* @param page The page to process.
* @param content The contents of the page.
*
* @throws IOException If there is an error processing the page.
*/
protected void processPage( PDPage page, COSStream content ) throws IOException
{
if( currentPageNo >= startPage && currentPageNo <= endPage &&
(startBookmarkPageNumber == -1 || currentPageNo >= startBookmarkPageNumber ) &&
(endBookmarkPageNumber == -1 || currentPageNo <= endBookmarkPageNumber ))
{
startPage( page );
int numberOfArticleSections = 1;
if (shouldSeparateByBeads)
{
fillBeadRectangles(page);
numberOfArticleSections += beadRectangles.size() * 2;
}
int originalSize = charactersByArticle.size();
charactersByArticle.setSize( numberOfArticleSections );
for( int i=0; i)charactersByArticle.get( i )).clear();
}
else
{
charactersByArticle.set( i, new ArrayList() );
}
}
characterListMapping.clear();
processStream( page, page.findResources(), content );
writePage();
endPage( page );
}
}
private void fillBeadRectangles(PDPage page)
{
beadRectangles = new ArrayList();
for (PDThreadBead bead : page.getThreadBeads())
{
if (bead == null)
{
// can't skip, because of null entry handling in processTextPosition()
beadRectangles.add(null);
continue;
}
PDRectangle rect = bead.getRectangle();
// bead rectangle is in PDF coordinates (y=0 is bottom),
// glyphs are in image coordinates (y=0 is top),
// so we must flip
PDRectangle mediaBox = page.findMediaBox();
float upperRightY = mediaBox.getUpperRightY() - rect.getLowerLeftY();
float lowerLeftY = mediaBox.getUpperRightY() - rect.getUpperRightY();
rect.setLowerLeftY(lowerLeftY);
rect.setUpperRightY(upperRightY);
// adjust for cropbox
PDRectangle cropBox = page.findCropBox();
if (cropBox.getLowerLeftX() != 0 || cropBox.getLowerLeftY() != 0)
{
rect.setLowerLeftX(rect.getLowerLeftX() - cropBox.getLowerLeftX());
rect.setLowerLeftY(rect.getLowerLeftY() - cropBox.getLowerLeftY());
rect.setUpperRightX(rect.getUpperRightX() - cropBox.getLowerLeftX());
rect.setUpperRightY(rect.getUpperRightY() - cropBox.getLowerLeftY());
}
beadRectangles.add(rect);
}
}
/**
* Start a new article, which is typically defined as a column
* on a single page (also referred to as a bead). This assumes
* that the primary direction of text is left to right.
* Default implementation is to do nothing. Subclasses
* may provide additional information.
*
* @throws IOException If there is any error writing to the stream.
*/
protected void startArticle() throws IOException
{
startArticle(true);
}
/**
* Start a new article, which is typically defined as a column
* on a single page (also referred to as a bead).
* Default implementation is to do nothing. Subclasses
* may provide additional information.
*
* @param isltr true if primary direction of text is left to right.
* @throws IOException If there is any error writing to the stream.
*/
protected void startArticle(boolean isltr) throws IOException
{
output.write(getArticleStart());
}
/**
* End an article. Default implementation is to do nothing. Subclasses
* may provide additional information.
*
* @throws IOException If there is any error writing to the stream.
*/
protected void endArticle() throws IOException
{
output.write(getArticleEnd());
}
/**
* Start a new page. Default implementation is to do nothing. Subclasses
* may provide additional information.
*
* @param page The page we are about to process.
*
* @throws IOException If there is any error writing to the stream.
*/
protected void startPage( PDPage page ) throws IOException
{
//default is to do nothing.
}
/**
* End a page. Default implementation is to do nothing. Subclasses
* may provide additional information.
*
* @param page The page we are about to process.
*
* @throws IOException If there is any error writing to the stream.
*/
protected void endPage( PDPage page ) throws IOException
{
//default is to do nothing
}
private static final float ENDOFLASTTEXTX_RESET_VALUE = -1;
private static final float MAXYFORLINE_RESET_VALUE = -Float.MAX_VALUE;
private static final float EXPECTEDSTARTOFNEXTWORDX_RESET_VALUE = -Float.MAX_VALUE;
private static final float MAXHEIGHTFORLINE_RESET_VALUE = -1;
private static final float MINYTOPFORLINE_RESET_VALUE = Float.MAX_VALUE;
private static final float LASTWORDSPACING_RESET_VALUE = -1;
/**
* This will print the text of the processed page to "output".
* It will estimate, based on the coordinates of the text, where
* newlines and word spacings should be placed. The text will be
* sorted only if that feature was enabled.
*
* @throws IOException If there is an error writing the text.
*/
protected void writePage() throws IOException
{
float maxYForLine = MAXYFORLINE_RESET_VALUE;
float minYTopForLine = MINYTOPFORLINE_RESET_VALUE;
float endOfLastTextX = ENDOFLASTTEXTX_RESET_VALUE;
float lastWordSpacing = LASTWORDSPACING_RESET_VALUE;
float maxHeightForLine = MAXHEIGHTFORLINE_RESET_VALUE;
PositionWrapper lastPosition = null;
PositionWrapper lastLineStartPosition = null;
boolean startOfPage = true;//flag to indicate start of page
boolean startOfArticle = true;
if(charactersByArticle.size() > 0)
{
writePageStart();
}
for( int i = 0; i < charactersByArticle.size(); i++)
{
List textList = charactersByArticle.get( i );
if( getSortByPosition() )
{
TextPositionComparator comparator = new TextPositionComparator();
// because the TextPositionComparator is not transitive, but
// JDK7+ enforces transitivity on comparators, we need to use
// a custom quicksort implementation (which is slower, unfortunately).
if(useCustomQuicksort)
{
QuickSort.sort( textList, comparator );
}
else
{
Collections.sort( textList, comparator );
}
}
Iterator textIter = textList.iterator();
/* Before we can display the text, we need to do some normalizing.
* Arabic and Hebrew text is right to left and is typically stored
* in its logical format, which means that the rightmost character is
* stored first, followed by the second character from the right etc.
* However, PDF stores the text in presentation form, which is left to
* right. We need to do some normalization to convert the PDF data to
* the proper logical output format.
*
* Note that if we did not sort the text, then the output of reversing the
* text is undefined and can sometimes produce worse output then not trying
* to reverse the order. Sorting should be done for these languages.
* */
/* First step is to determine if we have any right to left text, and
* if so, is it dominant. */
int ltrCnt = 0;
int rtlCnt = 0;
while( textIter.hasNext() )
{
TextPosition position = (TextPosition)textIter.next();
String stringValue = position.getCharacter();
for (int a = 0; a < stringValue.length(); a++)
{
byte dir = Character.getDirectionality(stringValue.charAt(a));
if ((dir == Character.DIRECTIONALITY_LEFT_TO_RIGHT ) ||
(dir == Character.DIRECTIONALITY_LEFT_TO_RIGHT_EMBEDDING) ||
(dir == Character.DIRECTIONALITY_LEFT_TO_RIGHT_OVERRIDE ))
{
ltrCnt++;
}
else if ((dir == Character.DIRECTIONALITY_RIGHT_TO_LEFT ) ||
(dir == Character.DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC) ||
(dir == Character.DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING) ||
(dir == Character.DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE ))
{
rtlCnt++;
}
}
}
// choose the dominant direction
boolean isRtlDominant = rtlCnt > ltrCnt;
startArticle(!isRtlDominant);
startOfArticle = true;
// we will later use this to skip reordering
boolean hasRtl = rtlCnt > 0;
/* Now cycle through to print the text.
* We queue up a line at a time before we print so that we can convert
* the line from presentation form to logical form (if needed).
*/
List line = new ArrayList();
textIter = textList.iterator(); // start from the beginning again
/* PDF files don't always store spaces. We will need to guess where we should add
* spaces based on the distances between TextPositions. Historically, this was done
* based on the size of the space character provided by the font. In general, this worked
* but there were cases where it did not work. Calculating the average character width
* and using that as a metric works better in some cases but fails in some cases where the
* spacing worked. So we use both. NOTE: Adobe reader also fails on some of these examples.
*/
//Keeps track of the previous average character width
float previousAveCharWidth = -1;
while( textIter.hasNext() )
{
TextPosition position = (TextPosition)textIter.next();
PositionWrapper current = new PositionWrapper(position);
String characterValue = position.getCharacter();
//Resets the average character width when we see a change in font
// or a change in the font size
if(lastPosition != null && ((position.getFont() != lastPosition.getTextPosition().getFont())
|| (position.getFontSize() != lastPosition.getTextPosition().getFontSize())))
{
previousAveCharWidth = -1;
}
float positionX;
float positionY;
float positionWidth;
float positionHeight;
/* If we are sorting, then we need to use the text direction
* adjusted coordinates, because they were used in the sorting. */
if (getSortByPosition())
{
positionX = position.getXDirAdj();
positionY = position.getYDirAdj();
positionWidth = position.getWidthDirAdj();
positionHeight = position.getHeightDir();
}
else
{
positionX = position.getX();
positionY = position.getY();
positionWidth = position.getWidth();
positionHeight = position.getHeight();
}
//The current amount of characters in a word
int wordCharCount = position.getIndividualWidths().length;
/* Estimate the expected width of the space based on the
* space character with some margin. */
float wordSpacing = position.getWidthOfSpace();
float deltaSpace = 0;
if (wordSpacing == 0 || Float.isNaN(wordSpacing))
{
deltaSpace = Float.MAX_VALUE;
}
else
{
if( lastWordSpacing < 0 )
{
deltaSpace = (wordSpacing * getSpacingTolerance());
}
else
{
deltaSpace = (((wordSpacing+lastWordSpacing)/2f)* getSpacingTolerance());
}
}
/* Estimate the expected width of the space based on the
* average character width with some margin. This calculation does not
* make a true average (average of averages) but we found that it gave the
* best results after numerous experiments. Based on experiments we also found that
* .3 worked well. */
float averageCharWidth = -1;
if(previousAveCharWidth < 0)
{
averageCharWidth = (positionWidth/wordCharCount);
}
else
{
averageCharWidth = (previousAveCharWidth + (positionWidth/wordCharCount))/2f;
}
float deltaCharWidth = (averageCharWidth * getAverageCharTolerance());
//Compares the values obtained by the average method and the wordSpacing method and picks
//the smaller number.
float expectedStartOfNextWordX = EXPECTEDSTARTOFNEXTWORDX_RESET_VALUE;
if(endOfLastTextX != ENDOFLASTTEXTX_RESET_VALUE)
{
if(deltaCharWidth > deltaSpace)
{
expectedStartOfNextWordX = endOfLastTextX + deltaSpace;
}
else
{
expectedStartOfNextWordX = endOfLastTextX + deltaCharWidth;
}
}
if( lastPosition != null )
{
if(startOfArticle)
{
lastPosition.setArticleStart();
startOfArticle = false;
}
// RDD - Here we determine whether this text object is on the current
// line. We use the lastBaselineFontSize to handle the superscript
// case, and the size of the current font to handle the subscript case.
// Text must overlap with the last rendered baseline text by at least
// a small amount in order to be considered as being on the same line.
/* XXX BC: In theory, this check should really check if the next char is in full range
* seen in this line. This is what I tried to do with minYTopForLine, but this caused a lot
* of regression test failures. So, I'm leaving it be for now. */
if(!overlap(positionY, positionHeight, maxYForLine, maxHeightForLine))
{
writeLine(normalize(line,isRtlDominant,hasRtl),isRtlDominant);
line.clear();
lastLineStartPosition =
handleLineSeparation(current, lastPosition, lastLineStartPosition, maxHeightForLine);
endOfLastTextX = ENDOFLASTTEXTX_RESET_VALUE;
expectedStartOfNextWordX = EXPECTEDSTARTOFNEXTWORDX_RESET_VALUE;
maxYForLine = MAXYFORLINE_RESET_VALUE;
maxHeightForLine = MAXHEIGHTFORLINE_RESET_VALUE;
minYTopForLine = MINYTOPFORLINE_RESET_VALUE;
}
//Test if our TextPosition starts after a new word would be expected to start.
if (expectedStartOfNextWordX != EXPECTEDSTARTOFNEXTWORDX_RESET_VALUE
&& expectedStartOfNextWordX < positionX &&
//only bother adding a space if the last character was not a space
lastPosition.getTextPosition().getCharacter() != null &&
!lastPosition.getTextPosition().getCharacter().endsWith( " " ) )
{
line.add(WordSeparator.getSeparator());
}
}
if (positionY >= maxYForLine)
{
maxYForLine = positionY;
}
// RDD - endX is what PDF considers to be the x coordinate of the
// end position of the text. We use it in computing our metrics below.
endOfLastTextX = positionX + positionWidth;
// add it to the list
if (characterValue != null)
{
if(startOfPage && lastPosition==null)
{
writeParagraphStart();//not sure this is correct for RTL?
}
line.add(position);
}
maxHeightForLine = Math.max( maxHeightForLine, positionHeight );
minYTopForLine = Math.min(minYTopForLine,positionY - positionHeight);
lastPosition = current;
if(startOfPage)
{
lastPosition.setParagraphStart();
lastPosition.setLineStart();
lastLineStartPosition = lastPosition;
startOfPage=false;
}
lastWordSpacing = wordSpacing;
previousAveCharWidth = averageCharWidth;
}
// print the final line
if (line.size() > 0)
{
writeLine(normalize(line,isRtlDominant,hasRtl),isRtlDominant);
writeParagraphEnd();
}
endArticle();
}
writePageEnd();
}
private boolean overlap( float y1, float height1, float y2, float height2 )
{
return within( y1, y2, .1f) || (y2 <= y1 && y2 >= y1-height1) ||
(y1 <= y2 && y1 >= y2-height2);
}
/**
* Write the page separator value to the output stream.
* @throws IOException
* If there is a problem writing out the pageseparator to the document.
*/
protected void writePageSeperator() throws IOException
{
// RDD - newline at end of flush - required for end of page (so that the top
// of the next page starts on its own line.
output.write(getPageSeparator());
output.flush();
}
/**
* Write the line separator value to the output stream.
* @throws IOException
* If there is a problem writing out the lineseparator to the document.
*/
protected void writeLineSeparator( ) throws IOException
{
output.write(getLineSeparator());
}
/**
* Write the word separator value to the output stream.
* @throws IOException
* If there is a problem writing out the wordseparator to the document.
*/
protected void writeWordSeparator() throws IOException
{
output.write(getWordSeparator());
}
/**
* Write the string in TextPosition to the output stream.
*
* @param text The text to write to the stream.
* @throws IOException If there is an error when writing the text.
*/
protected void writeCharacters( TextPosition text ) throws IOException
{
output.write( text.getCharacter() );
}
/**
* Write a Java string to the output stream. The default implementation will ignore the textPositions
* and just calls {@link #writeString(String)}.
*
* @param text The text to write to the stream.
* @param textPositions The TextPositions belonging to the text.
* @throws IOException If there is an error when writing the text.
*/
protected void writeString(String text, List textPositions) throws IOException
{
writeString(text);
}
/**
* Write a Java string to the output stream.
*
* @param text The text to write to the stream.
* @throws IOException If there is an error when writing the text.
*/
protected void writeString( String text ) throws IOException
{
output.write( text );
}
/**
* This will determine of two floating point numbers are within a specified variance.
*
* @param first The first number to compare to.
* @param second The second number to compare to.
* @param variance The allowed variance.
*/
private boolean within( float first, float second, float variance )
{
return second < first + variance && second > first - variance;
}
/**
* This will process a TextPosition object and add the
* text to the list of characters on a page. It takes care of
* overlapping text.
*
* @param text The text to process.
*/
protected void processTextPosition( TextPosition text )
{
boolean showCharacter = true;
if( suppressDuplicateOverlappingText )
{
showCharacter = false;
String textCharacter = text.getCharacter();
float textX = text.getX();
float textY = text.getY();
TreeMap> sameTextCharacters = characterListMapping.get( textCharacter );
if( sameTextCharacters == null )
{
sameTextCharacters = new TreeMap>();
characterListMapping.put( textCharacter, sameTextCharacters );
}
// RDD - Here we compute the value that represents the end of the rendered
// text. This value is used to determine whether subsequent text rendered
// on the same line overwrites the current text.
//
// We subtract any positive padding to handle cases where extreme amounts
// of padding are applied, then backed off (not sure why this is done, but there
// are cases where the padding is on the order of 10x the character width, and
// the TJ just backs up to compensate after each character). Also, we subtract
// an amount to allow for kerning (a percentage of the width of the last
// character).
//
boolean suppressCharacter = false;
float tolerance = (text.getWidth()/textCharacter.length())/3.0f;
SortedMap> xMatches =
sameTextCharacters.subMap(textX - tolerance, textX + tolerance );
for (TreeSet xMatch : xMatches.values())
{
SortedSet yMatches =
xMatch.subSet(textY - tolerance , textY + tolerance );
if (!yMatches.isEmpty())
{
suppressCharacter = true;
break;
}
}
if( !suppressCharacter )
{
TreeSet ySet = sameTextCharacters.get(textX);
if (ySet == null)
{
ySet = new TreeSet();
sameTextCharacters.put( textX, ySet );
}
ySet.add( textY );
showCharacter = true;
}
}
if( showCharacter )
{
//if we are showing the character then we need to determine which
//article it belongs to.
int foundArticleDivisionIndex = -1;
int notFoundButFirstLeftAndAboveArticleDivisionIndex = -1;
int notFoundButFirstLeftArticleDivisionIndex = -1;
int notFoundButFirstAboveArticleDivisionIndex = -1;
float x = text.getX();
float y = text.getY();
if (shouldSeparateByBeads)
{
for (int i = 0; i < beadRectangles.size() && foundArticleDivisionIndex == -1; i++)
{
PDRectangle rect = beadRectangles.get(i);
if( rect != null )
{
if( rect.contains( x, y ) )
{
foundArticleDivisionIndex = i*2+1;
}
else if( (x < rect.getLowerLeftX() ||
y < rect.getUpperRightY()) &&
notFoundButFirstLeftAndAboveArticleDivisionIndex == -1)
{
notFoundButFirstLeftAndAboveArticleDivisionIndex = i*2;
}
else if( x < rect.getLowerLeftX() &&
notFoundButFirstLeftArticleDivisionIndex == -1)
{
notFoundButFirstLeftArticleDivisionIndex = i*2;
}
else if( y < rect.getUpperRightY() &&
notFoundButFirstAboveArticleDivisionIndex == -1)
{
notFoundButFirstAboveArticleDivisionIndex = i*2;
}
}
else
{
foundArticleDivisionIndex = 0;
}
}
}
else
{
foundArticleDivisionIndex = 0;
}
int articleDivisionIndex = -1;
if( foundArticleDivisionIndex != -1 )
{
articleDivisionIndex = foundArticleDivisionIndex;
}
else if( notFoundButFirstLeftAndAboveArticleDivisionIndex != -1 )
{
articleDivisionIndex = notFoundButFirstLeftAndAboveArticleDivisionIndex;
}
else if( notFoundButFirstLeftArticleDivisionIndex != -1 )
{
articleDivisionIndex = notFoundButFirstLeftArticleDivisionIndex;
}
else if( notFoundButFirstAboveArticleDivisionIndex != -1 )
{
articleDivisionIndex = notFoundButFirstAboveArticleDivisionIndex;
}
else
{
articleDivisionIndex = charactersByArticle.size()-1;
}
List textList = (List) charactersByArticle.get( articleDivisionIndex );
/* In the wild, some PDF encoded documents put diacritics (accents on
* top of characters) into a separate Tj element. When displaying them
* graphically, the two chunks get overlayed. With text output though,
* we need to do the overlay. This code recombines the diacritic with
* its associated character if the two are consecutive.
*/
if(textList.isEmpty())
{
textList.add(text);
}
else
{
/* test if we overlap the previous entry.
* Note that we are making an assumption that we need to only look back
* one TextPosition to find what we are overlapping.
* This may not always be true. */
TextPosition previousTextPosition = (TextPosition)textList.get(textList.size()-1);
if(text.isDiacritic() && previousTextPosition.contains(text))
{
previousTextPosition.mergeDiacritic(text, normalize);
}
/* If the previous TextPosition was the diacritic, merge it into this
* one and remove it from the list. */
else if(previousTextPosition.isDiacritic() && text.contains(previousTextPosition))
{
text.mergeDiacritic(previousTextPosition, normalize);
textList.remove(textList.size()-1);
textList.add(text);
}
else
{
textList.add(text);
}
}
}
}
/**
* This is the page that the text extraction will start on. The pages start
* at page 1. For example in a 5 page PDF document, if the start page is 1
* then all pages will be extracted. If the start page is 4 then pages 4 and 5
* will be extracted. The default value is 1.
*
* @return Value of property startPage.
*/
public int getStartPage()
{
return startPage;
}
/**
* This will set the first page to be extracted by this class.
*
* @param startPageValue New value of 1-based startPage property.
*/
public void setStartPage(int startPageValue)
{
startPage = startPageValue;
}
/**
* This will get the last page that will be extracted. This is inclusive,
* for example if a 5 page PDF an endPage value of 5 would extract the
* entire document, an end page of 2 would extract pages 1 and 2. This defaults
* to Integer.MAX_VALUE such that all pages of the pdf will be extracted.
*
* @return Value of property endPage.
*/
public int getEndPage()
{
return endPage;
}
/**
* This will set the last page to be extracted by this class.
*
* @param endPageValue New value of 1-based endPage property.
*/
public void setEndPage(int endPageValue)
{
endPage = endPageValue;
}
/**
* Set the desired line separator for output text. The line.separator
* system property is used if the line separator preference is not set
* explicitly using this method.
*
* @param separator The desired line separator string.
*/
public void setLineSeparator(String separator)
{
lineSeparator = separator;
}
/**
* This will get the line separator.
*
* @return The desired line separator string.
*/
public String getLineSeparator()
{
return lineSeparator;
}
/**
* Set the desired page separator for output text. The line.separator
* system property is used if the page separator preference is not set
* explicitly using this method.
*
* @param separator The desired page separator string.
*
* @deprecated use {@link #setPageStart(String) and {@link #setPageEnd(String)} instead
*/
public void setPageSeparator(String separator)
{
pageSeparator = separator;
}
/**
* This will get the word separator.
*
* @return The desired word separator string.
*/
public String getWordSeparator()
{
return wordSeparator;
}
/**
* Set the desired word separator for output text. The PDFBox text extraction
* algorithm will output a space character if there is enough space between
* two words. By default a space character is used. If you need and accurate
* count of characters that are found in a PDF document then you might want to
* set the word separator to the empty string.
*
* @param separator The desired page separator string.
*/
public void setWordSeparator(String separator)
{
wordSeparator = separator;
}
/**
* This will get the page separator.
*
* @return The page separator string.
*
* @deprecated use {@link #getPageStart()} and {@link #getPageEnd()} instead
*/
public String getPageSeparator()
{
return pageSeparator;
}
/**
* @return Returns the suppressDuplicateOverlappingText.
*/
public boolean getSuppressDuplicateOverlappingText()
{
return suppressDuplicateOverlappingText;
}
/**
* Get the current page number that is being processed.
*
* @return A 1 based number representing the current page.
*/
protected int getCurrentPageNo()
{
return currentPageNo;
}
/**
* The output stream that is being written to.
*
* @return The stream that output is being written to.
*/
protected Writer getOutput()
{
return output;
}
/**
* Character strings are grouped by articles. It is quite common that there
* will only be a single article. This returns a List that contains List objects,
* the inner lists will contain TextPosition objects.
*
* @return A double List of TextPositions for all text strings on the page.
*/
protected Vector> getCharactersByArticle()
{
return charactersByArticle;
}
/**
* By default the text stripper will attempt to remove text that overlapps each other.
* Word paints the same character several times in order to make it look bold. By setting
* this to false all text will be extracted, which means that certain sections will be
* duplicated, but better performance will be noticed.
*
* @param suppressDuplicateOverlappingTextValue The suppressDuplicateOverlappingText to set.
*/
public void setSuppressDuplicateOverlappingText(
boolean suppressDuplicateOverlappingTextValue)
{
suppressDuplicateOverlappingText = suppressDuplicateOverlappingTextValue;
}
/**
* This will tell if the text stripper should separate by beads.
*
* @return If the text will be grouped by beads.
*/
public boolean getSeparateByBeads()
{
return shouldSeparateByBeads;
}
/**
* Set if the text stripper should group the text output by a list of beads. The default value is true!
*
* @param aShouldSeparateByBeads The new grouping of beads.
*/
public void setShouldSeparateByBeads(boolean aShouldSeparateByBeads)
{
shouldSeparateByBeads = aShouldSeparateByBeads;
}
/**
* Get the bookmark where text extraction should end, inclusive. Default is null.
*
* @return The ending bookmark.
*/
public PDOutlineItem getEndBookmark()
{
return endBookmark;
}
/**
* Set the bookmark where the text extraction should stop.
*
* @param aEndBookmark The ending bookmark.
*/
public void setEndBookmark(PDOutlineItem aEndBookmark)
{
endBookmark = aEndBookmark;
}
/**
* Get the bookmark where text extraction should start, inclusive. Default is null.
*
* @return The starting bookmark.
*/
public PDOutlineItem getStartBookmark()
{
return startBookmark;
}
/**
* Set the bookmark where text extraction should start, inclusive.
*
* @param aStartBookmark The starting bookmark.
*/
public void setStartBookmark(PDOutlineItem aStartBookmark)
{
startBookmark = aStartBookmark;
}
/**
* This will tell if the text stripper should add some more text formatting.
* @return true if some more text formatting will be added
*/
public boolean getAddMoreFormatting()
{
return addMoreFormatting;
}
/**
* There will some additional text formatting be added if addMoreFormatting
* is set to true. Default is false.
* @param newAddMoreFormatting Tell PDFBox to add some more text formatting
*/
public void setAddMoreFormatting(boolean newAddMoreFormatting)
{
addMoreFormatting = newAddMoreFormatting;
}
/**
* This will tell if the text stripper should sort the text tokens
* before writing to the stream.
*
* @return true If the text tokens will be sorted before being written.
*/
public boolean getSortByPosition()
{
return sortByPosition;
}
/**
* The order of the text tokens in a PDF file may not be in the same
* as they appear visually on the screen. For example, a PDF writer may
* write out all text by font, so all bold or larger text, then make a second
* pass and write out the normal text.
* The default is to not sort by position.
*
* A PDF writer could choose to write each character in a different order. By
* default PDFBox does not sort the text tokens before processing them due to
* performance reasons.
*
* @param newSortByPosition Tell PDFBox to sort the text positions.
*/
public void setSortByPosition(boolean newSortByPosition)
{
sortByPosition = newSortByPosition;
}
/**
* Get the current space width-based tolerance value that is being used
* to estimate where spaces in text should be added. Note that the
* default value for this has been determined from trial and error.
*
* @return The current tolerance / scaling factor
*/
public float getSpacingTolerance()
{
return spacingTolerance;
}
/**
* Set the space width-based tolerance value that is used
* to estimate where spaces in text should be added. Note that the
* default value for this has been determined from trial and error.
* Setting this value larger will reduce the number of spaces added.
*
* @param spacingToleranceValue tolerance / scaling factor to use
*/
public void setSpacingTolerance(float spacingToleranceValue)
{
spacingTolerance = spacingToleranceValue;
}
/**
* Get the current character width-based tolerance value that is being used
* to estimate where spaces in text should be added. Note that the
* default value for this has been determined from trial and error.
*
* @return The current tolerance / scaling factor
*/
public float getAverageCharTolerance()
{
return averageCharTolerance;
}
/**
* Set the character width-based tolerance value that is used
* to estimate where spaces in text should be added. Note that the
* default value for this has been determined from trial and error.
* Setting this value larger will reduce the number of spaces added.
*
* @param averageCharToleranceValue average tolerance / scaling factor to use
*/
public void setAverageCharTolerance(float averageCharToleranceValue)
{
averageCharTolerance = averageCharToleranceValue;
}
/**
* returns the multiple of whitespace character widths
* for the current text which the current
* line start can be indented from the previous line start
* beyond which the current line start is considered
* to be a paragraph start.
* @return the number of whitespace character widths to use
* when detecting paragraph indents.
*/
public float getIndentThreshold()
{
return indentThreshold;
}
/**
* sets the multiple of whitespace character widths
* for the current text which the current
* line start can be indented from the previous line start
* beyond which the current line start is considered
* to be a paragraph start. The default value is 2.0.
*
* @param indentThresholdValue the number of whitespace character widths to use
* when detecting paragraph indents.
*/
public void setIndentThreshold(float indentThresholdValue)
{
indentThreshold = indentThresholdValue;
}
/**
* the minimum whitespace, as a multiple
* of the max height of the current characters
* beyond which the current line start is considered
* to be a paragraph start.
* @return the character height multiple for
* max allowed whitespace between lines in
* the same paragraph.
*/
public float getDropThreshold()
{
return dropThreshold;
}
/**
* sets the minimum whitespace, as a multiple
* of the max height of the current characters
* beyond which the current line start is considered
* to be a paragraph start. The default value is 2.5.
*
* @param dropThresholdValue the character height multiple for
* max allowed whitespace between lines in
* the same paragraph.
*/
public void setDropThreshold(float dropThresholdValue)
{
dropThreshold = dropThresholdValue;
}
/**
* Returns the string which will be used at the beginning of a paragraph.
* @return the paragraph start string
*/
public String getParagraphStart()
{
return paragraphStart;
}
/**
* Sets the string which will be used at the beginning of a paragraph.
* @param s the paragraph start string
*/
public void setParagraphStart(String s)
{
paragraphStart = s;
}
/**
* Returns the string which will be used at the end of a paragraph.
* @return the paragraph end string
*/
public String getParagraphEnd()
{
return paragraphEnd;
}
/**
* Sets the string which will be used at the end of a paragraph.
* @param s the paragraph end string
*/
public void setParagraphEnd(String s)
{
paragraphEnd = s;
}
/**
* Returns the string which will be used at the beginning of a page.
* @return the page start string
*/
public String getPageStart()
{
return pageStart;
}
/**
* Sets the string which will be used at the beginning of a page.
* @param pageStartValue the page start string
*/
public void setPageStart(String pageStartValue)
{
pageStart = pageStartValue;
}
/**
* Returns the string which will be used at the end of a page.
* @return the page end string
*/
public String getPageEnd()
{
return pageEnd;
}
/**
* Sets the string which will be used at the end of a page.
* @param pageEndValue the page end string
*/
public void setPageEnd(String pageEndValue)
{
pageEnd = pageEndValue;
}
/**
* Returns the string which will be used at the beginning of an article.
* @return the article start string
*/
public String getArticleStart()
{
return articleStart;
}
/**
* Sets the string which will be used at the beginning of an article.
* @param articleStartValue the article start string
*/
public void setArticleStart(String articleStartValue)
{
articleStart = articleStartValue;
}
/**
* Returns the string which will be used at the end of an article.
* @return the article end string
*/
public String getArticleEnd()
{
return articleEnd;
}
/**
* Sets the string which will be used at the end of an article.
* @param articleEndValue the article end string
*/
public void setArticleEnd(String articleEndValue)
{
articleEnd = articleEndValue;
}
/**
* Reverse characters of a compound Arabic glyph.
* When getSortByPosition() is true, inspect the sequence encoded
* by one glyph. If the glyph encodes two or more Arabic characters,
* reverse these characters from a logical order to a visual order.
* This ensures that the bidirectional algorithm that runs later will
* convert them back to a logical order.
*
* @param str a string obtained from font.encoding()
*
* @return the reversed string
*/
public String inspectFontEncoding(String str)
{
if (!sortByPosition || str == null || str.length() < 2)
{
return str;
}
for (int i = 0; i < str.length(); ++i)
{
if (Character.getDirectionality(str.charAt(i))
!= Character.DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC)
{
return str;
}
}
StringBuilder reversed = new StringBuilder(str.length());
for (int i = str.length() - 1; i >= 0; --i)
{
reversed.append(str.charAt(i));
}
return reversed.toString();
}
/**
* handles the line separator for a new line given
* the specified current and previous TextPositions.
* @param current the current text position
* @param lastPosition the previous text position
* @param lastLineStartPosition the last text position that followed a line
* separator.
* @param maxHeightForLine max height for positions since lastLineStartPosition
* @return start position of the last line
* @throws IOException if something went wrong
*/
protected PositionWrapper handleLineSeparation(PositionWrapper current,
PositionWrapper lastPosition, PositionWrapper lastLineStartPosition, float maxHeightForLine)
throws IOException
{
current.setLineStart();
isParagraphSeparation(current, lastPosition, lastLineStartPosition, maxHeightForLine);
lastLineStartPosition = current;
if (current.isParagraphStart())
{
if(lastPosition.isArticleStart())
{
writeParagraphStart();
}
else
{
writeLineSeparator();
writeParagraphSeparator();
}
}
else
{
writeLineSeparator();
}
return lastLineStartPosition;
}
/**
* tests the relationship between the last text position, the current text
* position and the last text position that followed a line separator to
* decide if the gap represents a paragraph separation. This should
* only be called for consecutive text positions that first pass the
* line separation test.
*
* This base implementation tests to see if the lastLineStartPosition is
* null OR if the current vertical position has dropped below the last text
* vertical position by at least 2.5 times the current text height OR if the
* current horizontal position is indented by at least 2 times the current
* width of a space character.
*
* This also attempts to identify text that is indented under a hanging indent.
*
* This method sets the isParagraphStart and isHangingIndent flags on the current
* position object.
*
* @param position the current text position. This may have its isParagraphStart
* or isHangingIndent flags set upon return.
* @param lastPosition the previous text position (should not be null).
* @param lastLineStartPosition the last text position that followed a line
* separator. May be null.
* @param maxHeightForLine max height for text positions since lasLineStartPosition.
*/
protected void isParagraphSeparation(PositionWrapper position,
PositionWrapper lastPosition, PositionWrapper lastLineStartPosition, float maxHeightForLine)
{
boolean result = false;
if(lastLineStartPosition == null)
{
result = true;
}
else
{
float yGap = Math.abs(position.getTextPosition().getYDirAdj()-
lastPosition.getTextPosition().getYDirAdj());
float newYVal = multiplyFloat(getDropThreshold(), maxHeightForLine);
// do we need to flip this for rtl?
float xGap = position.getTextPosition().getXDirAdj() -
lastLineStartPosition.getTextPosition().getXDirAdj();
float newXVal = multiplyFloat(getIndentThreshold(), position.getTextPosition().getWidthOfSpace());
float positionWidth = multiplyFloat(0.25f, position.getTextPosition().getWidth());
if (yGap > newYVal)
{
result = true;
}
else if (xGap > newXVal)
{
//text is indented, but try to screen for hanging indent
if(!lastLineStartPosition.isParagraphStart())
{
result = true;
}
else
{
position.setHangingIndent();
}
}
else if(xGap < -position.getTextPosition().getWidthOfSpace())
{
//text is left of previous line. Was it a hanging indent?
if(!lastLineStartPosition.isParagraphStart())
{
result = true;
}
}
else if (Math.abs(xGap) < positionWidth)
{
//current horizontal position is within 1/4 a char of the last
//linestart. We'll treat them as lined up.
if(lastLineStartPosition.isHangingIndent())
{
position.setHangingIndent();
}
else if(lastLineStartPosition.isParagraphStart())
{
//check to see if the previous line looks like
//any of a number of standard list item formats
Pattern liPattern = matchListItemPattern(lastLineStartPosition);
if(liPattern!=null)
{
Pattern currentPattern = matchListItemPattern(position);
if(liPattern == currentPattern)
{
result = true;
}
}
}
}
}
if(result)
{
position.setParagraphStart();
}
}
private float multiplyFloat(float value1, float value2)
{
// multiply 2 floats and truncate the resulting value to 3 decimal places
// to avoid wrong results when comparing with another float
return Math.round(value1 * value2 * 1000) / 1000f;
}
/**
* writes the paragraph separator string to the output.
* @throws IOException if something went wrong
*/
protected void writeParagraphSeparator()throws IOException
{
writeParagraphEnd();
writeParagraphStart();
}
/**
* Write something (if defined) at the start of a paragraph.
* @throws IOException if something went wrong
*/
protected void writeParagraphStart() throws IOException
{
if (inParagraph)
{
writeParagraphEnd();
inParagraph = false;
}
output.write(getParagraphStart());
inParagraph = true;
}
/**
* Write something (if defined) at the end of a paragraph.
* @throws IOException if something went wrong
*/
protected void writeParagraphEnd() throws IOException
{
if (!inParagraph)
{
writeParagraphStart();
}
output.write(getParagraphEnd());
inParagraph = false;
}
/**
* Write something (if defined) at the start of a page.
* @throws IOException if something went wrong
*/
protected void writePageStart()throws IOException
{
output.write(getPageStart());
}
/**
* Write something (if defined) at the end of a page.
* @throws IOException if something went wrong
*/
protected void writePageEnd()throws IOException
{
output.write(getPageEnd());
}
/**
* returns the list item Pattern object that matches
* the text at the specified PositionWrapper or null
* if the text does not match such a pattern. The list
* of Patterns tested against is given by the
* {@link #getListItemPatterns()} method. To add to
* the list, simply override that method (if sub-classing)
* or explicitly supply your own list using
* {@link #setListItemPatterns(List)}.
* @param pw position
* @return the matching pattern
*/
protected Pattern matchListItemPattern(PositionWrapper pw)
{
TextPosition tp = pw.getTextPosition();
String txt = tp.getCharacter();
return matchPattern(txt,getListItemPatterns());
}
/**
* a list of regular expressions that match commonly used
* list item formats, i.e. bullets, numbers, letters,
* Roman numerals, etc. Not meant to be
* comprehensive.
*/
private static final String[] LIST_ITEM_EXPRESSIONS = {
"\\.",
"\\d+\\.",
"\\[\\d+\\]",
"\\d+\\)",
"[A-Z]\\.",
"[a-z]\\.",
"[A-Z]\\)",
"[a-z]\\)",
"[IVXL]+\\.",
"[ivxl]+\\.",
};
private List listOfPatterns = null;
/**
* use to supply a different set of regular expression
* patterns for matching list item starts.
*
* @param patterns list of patterns
*/
protected void setListItemPatterns(List patterns)
{
listOfPatterns = patterns;
}
/**
* returns a list of regular expression Patterns representing
* different common list item formats. For example
* numbered items of form:
*
* - some text
* - more text
*
* or
*
* - some text
* - more text
*
* etc., all begin with some character pattern. The pattern "\\d+\." (matches "1.", "2.", ...)
* or "\[\\d+\]" (matches "[1]", "[2]", ...).
*
* This method returns a list of such regular expression Patterns.
* @return a list of Pattern objects.
*/
protected List getListItemPatterns()
{
if(listOfPatterns == null)
{
listOfPatterns = new ArrayList();
for(String expression : LIST_ITEM_EXPRESSIONS)
{
Pattern p = Pattern.compile(expression);
listOfPatterns.add(p);
}
}
return listOfPatterns;
}
/**
* iterates over the specified list of Patterns until
* it finds one that matches the specified string. Then
* returns the Pattern.
*
* Order of the supplied list of patterns is important as
* most common patterns should come first. Patterns
* should be strict in general, and all will be
* used with case sensitivity on.
*
* @param string the string to be searched
* @param patterns list of patterns
* @return matching pattern
*/
protected static final Pattern matchPattern(String string, List patterns)
{
Pattern matchedPattern = null;
for(Pattern p : patterns)
{
if(p.matcher(string).matches())
{
return p;
}
}
return matchedPattern;
}
/**
* Write a list of string containing a whole line of a document.
* @param line a list with the words of the given line
* @param isRtlDominant determines if rtl or ltl is dominant
* @throws IOException if something went wrong
*/
private void writeLine(List line, boolean isRtlDominant) throws IOException
{
int numberOfStrings = line.size();
for(int i=0; i normalize(List line, boolean isRtlDominant, boolean hasRtl)
{
LinkedList normalized = new LinkedList();
StringBuilder lineBuilder = new StringBuilder();
List wordPositions = new ArrayList();
// concatenate the pieces of text in opposite order if RTL is dominant
if (isRtlDominant)
{
int numberOfPositions = line.size();
for(int i = numberOfPositions-1;i>=0;i--)
{
lineBuilder = normalizeAdd(normalized, lineBuilder, wordPositions, line.get(i));
}
}
else
{
for(TextPosition text : line)
{
lineBuilder = normalizeAdd(normalized, lineBuilder, wordPositions, text);
}
}
if (lineBuilder.length() > 0)
{
normalized.add(createWord(lineBuilder.toString(), wordPositions));
}
return normalized;
}
/**
* Used within {@link #normalize(List, boolean, boolean)} to create a single {@link WordWithTextPositions}
* entry.
*/
private WordWithTextPositions createWord(String word, List wordPositions)
{
return new WordWithTextPositions(normalize.normalizePres(word), wordPositions);
}
/**
* 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 normalized,
StringBuilder lineBuilder, List wordPositions, TextPosition text)
{
if (text instanceof WordSeparator)
{
normalized.add(createWord(lineBuilder.toString(), new ArrayList(wordPositions)));
lineBuilder = new StringBuilder();
wordPositions.clear();
}
else
{
lineBuilder.append(text.getCharacter());
wordPositions.add(text);
}
return lineBuilder;
}
/**
* internal marker class. Used as a place holder in
* a line of TextPositions.
* @author ME21969
*
*/
private static final class WordSeparator extends TextPosition
{
private static final WordSeparator separator = new WordSeparator();
private WordSeparator()
{
}
public static final WordSeparator getSeparator()
{
return separator;
}
}
/**
* Internal class that maps strings to lists of {@link TextPosition} arrays.
* Note that the number of entries in that list may differ from the number of characters in the
* string due to normalization.
*
* @author Axel D?rfler
*/
private static final class WordWithTextPositions
{
protected String text;
protected List textPositions;
public WordWithTextPositions(String word, List positions)
{
text = word;
textPositions = positions;
}
public String getText()
{
return text;
}
public List getTextPositions()
{
return textPositions;
}
}
}