Class PageExtractor
- java.lang.Object
-
- org.faceless.pdf2.PageExtractor
-
public class PageExtractor extends java.lang.Object
This class enables the extraction of text and images from a
PDFPage
. You can get one by calling thePDFParser.getPageExtractor(int)
method, assuming the PDF has the rights to let you extract text and/or images.Once you've got one, you can extract the text of the page as a
StringBuffer
by callinggetTextAsStringBuffer()
. Note that extracting text from PDF's is not an exact science - the internals of a PDF allow text to be displayed in any order, and features like superscript, subscript, rotated text and so on which are easy to display in PDF can only be approximated in plain text.Features like tables etc. have to be determined using heuristics, and some PDF's are encoded in a way that makes extracting their text almost impossible (storing each letter as an image, for example).
Depending on how the font has been stored, the library may replace unknown characters with a Unicode character in the private range (U+EF00 - U+EFFF). These replacements will be consistent, so if you find that U+EF01 is in fact the letter 'A', you can easily run a
String.replace()
on the string to correct the lettersExtracting BitMap images is a much simpler process. The
PageExtractor.Image
class represents an image on the current page. There is one instance for each time an image is drawn, although as an image is repeated each instance may contain the sameRenderedImage
. You can retrieve the list of images by calling thegetImages()
method.This class requires the Extended Edition plus Viewer license to operate. Although it may be freely used in the trial version of the library, the extracted text will have the letter 'e' replaced with the letter 'a'.
- Since:
- 2.6.2
-
-
Nested Class Summary
Nested Classes Modifier and Type Class Description class
PageExtractor.Image
A class representing a bitmap image which is extracted from thePageExtractor
.class
PageExtractor.Text
A class representing a piece of text which is extracted from thePageExtractor
.
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Field Summary
Fields Modifier and Type Field Description static java.util.Comparator<PageExtractor.Text>
DISPLAYORDER
A Comparator which can be used to sortPageExtractor.Text
objects into their "display" order - the order which they visibly appear on the page, and the order that is returned bygetTextInDisplayOrder()
static java.util.Comparator<PageExtractor.Text>
NATURALORDER
A Comparator which can be used to sortPageExtractor.Text
objects into their "natural" order - the order which they occur in the PDF page stream, and the order that is returned bygetTextUnordered()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description static java.util.Collection<PageExtractor.Text>
cropText(java.util.Collection<PageExtractor.Text> all, java.awt.Shape shape)
Given a Collection ofPageExtractor.Text
items, as returned bygetMatchingText()
,getTextUnordered()
orgetTextInDisplayOrder()
, return a new Collection which contains only Text that falls completely inside the specifiedShape
.java.util.Collection<PageExtractor.Image>
getImages()
Return everyPageExtractor.Image
on the page, in the order they were added to the page.java.util.Collection<PageExtractor.Text>
getMatchingNormalizedText(java.lang.String[] queries, boolean caseinsensitive)
Returns a Collection ofPageExtractor.Text
objects on this page that match any of the specified substrings, based on normalized text.java.util.Collection<PageExtractor.Text>
getMatchingNormalizedText(java.util.regex.Pattern pattern)
Returns a Collection ofPageExtractor.Text
objects on this page that match the specified regular expression, based on normalized text.java.util.Collection<PageExtractor.Text>
getMatchingText(java.lang.String query)
Return a Collection ofPageExtractor.Text
items on this page that are equal to the specified substring.java.util.Collection<PageExtractor.Text>
getMatchingText(java.lang.String[] queries)
Return a Collection ofPageExtractor.Text
items on this page that are equals to one of the specified substrings.java.util.Collection<PageExtractor.Text>
getMatchingText(java.lang.String[] queries, boolean caseinsensitive)
Return a Collection ofPageExtractor.Text
items on this page that are equals to one of the specified substrings.java.util.Collection<PageExtractor.Text>
getMatchingText(java.util.regex.Pattern pattern)
Return a Collection ofPageExtractor.Text
items on this page that match the specified Regular Expression.PDFPage
getPage()
Return thePDFPage
this PageExtractor relates tojava.text.AttributedString
getStyledText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, boolean displayorder)
Deprecated.java.text.AttributedString
getStyledText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, java.util.Comparator<PageExtractor.Text> order)
Return an AttributedString containing a contiguous range of text from this PageExtractor.java.util.Collection<PageExtractor.Text>
getText(java.util.Comparator<PageExtractor.Text> comp)
Return everyPageExtractor.Text
item on the page, in the specified order.java.lang.StringBuffer
getText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, boolean displayorder)
Deprecated.java.lang.StringBuffer
getText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, java.util.Comparator<PageExtractor.Text> order)
Return a StringBuffer containing a contiguous range of text from this PageExtractor.java.lang.StringBuffer
getTextAsStringBuffer()
Parse and return all the text on the page as a StringBuffer.java.lang.StringBuffer
getTextAsStringBuffer(float x1, float y1, float x2, float y2)
Parse and return the text in the specified area on the page as a String.java.util.Collection<PageExtractor.Text>
getTextInDisplayOrder()
Return everyPageExtractor.Text
item on the page, in the order they are displayed on the screen - so the first item in the returned collection will nearest to the top left of the page.java.util.Collection<PageExtractor.Text>
getTextUnordered()
Return everyPageExtractor.Text
item on the page, in the order they were added to the page.boolean
isExtracted()
Return true if the extraction has been run, false otherwise.void
setOption(java.lang.String key, java.lang.Object value)
Set an option to control text extraction.void
setSpaceTolerance(double zero, double one, double many)
Set the "space tolerance" - tunable parameters for the extractor to determine when two adjacent phrases of text are to be separated by zero, one or more than one space.
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Field Detail
-
NATURALORDER
public static final java.util.Comparator<PageExtractor.Text> NATURALORDER
A Comparator which can be used to sortPageExtractor.Text
objects into their "natural" order - the order which they occur in the PDF page stream, and the order that is returned bygetTextUnordered()
- Since:
- 2.11.26
-
DISPLAYORDER
public static final java.util.Comparator<PageExtractor.Text> DISPLAYORDER
A Comparator which can be used to sortPageExtractor.Text
objects into their "display" order - the order which they visibly appear on the page, and the order that is returned bygetTextInDisplayOrder()
- Since:
- 2.11.26
-
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Method Detail
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isExtracted
public boolean isExtracted()
Return true if the extraction has been run, false otherwise.- Since:
- 2.11.7
-
setOption
public void setOption(java.lang.String key, java.lang.Object value)
Set an option to control text extraction. These options are useful for specific cases, such as when working with the Adobe Highlight File Format but probably won't be required for general use. The following options are recognised.IgnoreArtifacts all | regex Set to all to ignore any text flagged as an "artifact" in the PDF stream, or set to a regular expression to match against artifacts to be ignored. RawText true | false Set to true to prevent any post-processing of the extracted text. If this option is set, getTextInDisplayOrder
,getTextAsStringBuffer
and similar methods cannot be used - onlygetTextUnordered()
will work- Since:
- 2.11.12
-
setSpaceTolerance
public void setSpaceTolerance(double zero, double one, double many)
Set the "space tolerance" - tunable parameters for the extractor to determine when two adjacent phrases of text are to be separated by zero, one or more than one space. Typically this won't need to be tuned by the end user, but if you find the spacing between the extracted text is less than ideal, you can tune it to some degree with this method. The perfect value will depend on the font, the language, layout, line justification and kerning.
The values are multipliers of the width of the "space" character - so 1 means "the width of one space". Typically the parameter to tune is "one", within a rough range of 0.25 to 0.7 - reduce it if you find words are being joined together, and increase it if words are being split into two. it.
- Parameters:
zero
- how far apart two characters should be in order for them to be joined by zero spaces. The default value is -0.5one
- at least how far apart two characters must be in order to be joined by one space. The default value is 0.666.many
- at least how far apart two characters must be in order to be considered separate pieces of text. The default value is 1.5- Since:
- 2.11.2
-
getImages
public java.util.Collection<PageExtractor.Image> getImages()
Return everyPageExtractor.Image
on the page, in the order they were added to the page. Some images may be displayed more than once, in which case the value returned byPageExtractor.Image.getImage()
will be identical.- Returns:
- an unmodifiable collection of
PageExtractor.Image
elements.
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getTextUnordered
public java.util.Collection<PageExtractor.Text> getTextUnordered()
Return everyPageExtractor.Text
item on the page, in the order they were added to the page. The ordering may not be consistant with the order items are positioned on screen.- Returns:
- an unmodifiable collection of
PageExtractor.Text
elements.
-
getTextInDisplayOrder
public java.util.Collection<PageExtractor.Text> getTextInDisplayOrder()
Return everyPageExtractor.Text
item on the page, in the order they are displayed on the screen - so the first item in the returned collection will nearest to the top left of the page.- Returns:
- an unmodifiable collection of
PageExtractor.Text
elements.
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getText
public java.util.Collection<PageExtractor.Text> getText(java.util.Comparator<PageExtractor.Text> comp)
Return everyPageExtractor.Text
item on the page, in the specified order.- Parameters:
comp
- one ofNATURALORDER
orDISPLAYORDER
- Returns:
- an unmodifiable collection of
PageExtractor.Text
elements. - Since:
- 2.11.26
-
getMatchingText
public java.util.Collection<PageExtractor.Text> getMatchingText(java.lang.String query)
Return a Collection of
PageExtractor.Text
items on this page that are equal to the specified substring. The Text items returned fromgetTextInDisplayOrder()
are searched and possibly substrings extracted from them to create this collection. In this case the co-ordinates of the returned Text items will reflect the substring not the original Text object.As an example, the following method could be used to search a PDF for a specified word and add a "highlight" annotation over it. The PDF can then be rendered or saved as normal.
void highlightWords(PDF pdf, String word) { PDFParser parser = new PDFParser(pdf); for (int i=0;i<pdf.getNumberOfPages();i++) { PageExtractor extractor = parser.getPageExtractor(i); Collection co = extractor.getMatchingText(word); for (Iterator j = co.iterator();j.hasNext();) { PageExtractor.Text text = (PageExtractor.Text)j.next(); AnnotationMarkup annot = text.createAnnotationMarkup("Highlight"); text.getPage().getAnnotations().add(annot); } } }
- Parameters:
query
- the String to search for- Returns:
- a Collection of
PageExtractor.Text
objects. - Since:
- 2.6.12
-
getMatchingText
public java.util.Collection<PageExtractor.Text> getMatchingText(java.lang.String[] queries)
Return a Collection of
PageExtractor.Text
items on this page that are equals to one of the specified substrings. This method runs exactly likegetMatchingText(String)
but allows more than one substring to be matched.- Parameters:
queries
- a list of zero or more Strings to search for- Returns:
- a Collection of
PageExtractor.Text
objects. - Since:
- 2.8.1
-
getMatchingText
public java.util.Collection<PageExtractor.Text> getMatchingText(java.lang.String[] queries, boolean caseinsensitive)
Return a Collection of
PageExtractor.Text
items on this page that are equals to one of the specified substrings. This method runs exactly likegetMatchingText(String)
but allows more than one substring to be matched.- Parameters:
queries
- a list of zero or more Strings to search forcaseinsensitive
- whether the search should be performed with regard to case- Returns:
- a Collection of
PageExtractor.Text
objects. - Since:
- 2.11.1
-
getMatchingNormalizedText
public java.util.Collection<PageExtractor.Text> getMatchingNormalizedText(java.lang.String[] queries, boolean caseinsensitive)
Returns a Collection ofPageExtractor.Text
objects on this page that match any of the specified substrings, based on normalized text.- Since:
- 2.28.5
- See Also:
getMatchingText(String[], boolean)
,PageExtractor.Text.getNormalizedText()
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getMatchingText
public java.util.Collection<PageExtractor.Text> getMatchingText(java.util.regex.Pattern pattern)
Return a Collection of
PageExtractor.Text
items on this page that match the specified Regular Expression. This is likely to be more efficient than the version of this method that takes multiple-strings.- Parameters:
pattern
- thePattern
to search for- Returns:
- a Collection of
PageExtractor.Text
objects. - Since:
- 2.11
-
getMatchingNormalizedText
public java.util.Collection<PageExtractor.Text> getMatchingNormalizedText(java.util.regex.Pattern pattern)
Returns a Collection ofPageExtractor.Text
objects on this page that match the specified regular expression, based on normalized text.- Since:
- 2.28.5
- See Also:
getMatchingText(java.util.regex.Pattern)
,PageExtractor.Text.getNormalizedText()
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getTextAsStringBuffer
public java.lang.StringBuffer getTextAsStringBuffer()
Parse and return all the text on the page as a StringBuffer. Text will be converted back to it's normalized form, and newlines and spaces will be inserted in an approximation of the original layout.
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getTextAsStringBuffer
public java.lang.StringBuffer getTextAsStringBuffer(float x1, float y1, float x2, float y2)
Parse and return the text in the specified area on the page as a String. Text will be converted back to its normalized form, and newlines and spaces will be inserted in an approximation of the original layout. The co-ordinates define the start position of any phrases that are to be returned.- Parameters:
x1
- the left-most X co-ordinate of the texty1
- the top-most Y co-ordinate of the textx2
- the right-most X co-ordinate of the texty2
- the bottom-most Y co-ordinate of the text- Returns:
- a StringBuffer containing all the text within the specified rectangle
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getText
public java.lang.StringBuffer getText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, java.util.Comparator<PageExtractor.Text> order)
Return a StringBuffer containing a contiguous range of text from this PageExtractor. The range is specified by giving a starting and endingPageExtractor.Text
object, and the offsets into those strings: this method will then iterate over the appropriate order (getTextUnordered()
orgetTextInDisplayOrder()
) and include the appropriate range in the output. Note if you're selecting the entire range in display order this ordering is important, as the first/last must be the first/last items in that Collection.- Parameters:
first
- the first Text from this PageExtractor to be extractedfirstchar
- the index of the first character from "first" to be extractedlast
- the last Text from this PageExtractor to be extractedlastchar
- the index after the index of the last character from "last" to be extractedorder
- one ofNATURALORDER
orDISPLAYORDER
- Since:
- 2.10.3
-
getText
@Deprecated public java.lang.StringBuffer getText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, boolean displayorder)
Deprecated.Return a StringBuffer containing a contiguous range of text from this PageExtractor.- Since:
- 2.10.3
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getStyledText
public java.text.AttributedString getStyledText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, java.util.Comparator<PageExtractor.Text> order)
Return an AttributedString containing a contiguous range of text from this PageExtractor. The range is specified by giving a starting and endingPageExtractor.Text
object, and the offsets into those strings: this method will then iterate over the appropriate order (getTextUnordered()
orgetTextInDisplayOrder()
) and include the appropriate range in the output. Note if you're selecting the entire range in display order this ordering is important, as the first/last must be the first/last items in that Collection.- Parameters:
first
- the first Text from this PageExtractor to be extractedfirstchar
- the first character from "first" to be extractedlast
- the last Text from this PageExtractor to be extractedlastchar
- the index after the index of the last character from "last" to be extractedorder
- one ofNATURALORDER
orDISPLAYORDER
- Since:
- 2.11.26
-
getStyledText
@Deprecated public java.text.AttributedString getStyledText(PageExtractor.Text first, int firstchar, PageExtractor.Text last, int lastchar, boolean displayorder)
Deprecated.Return an AttributedString containing a contiguous range of text from this PageExtractor.- Since:
- 2.11.19
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cropText
public static java.util.Collection<PageExtractor.Text> cropText(java.util.Collection<PageExtractor.Text> all, java.awt.Shape shape)
Given a Collection ofPageExtractor.Text
items, as returned bygetMatchingText()
,getTextUnordered()
orgetTextInDisplayOrder()
, return a new Collection which contains only Text that falls completely inside the specifiedShape
. For example, to get all the text in a specific rectangle:Shape rect = new Rectangle2D.Float(0, 0, 100, 100); Collection all = extractor.trimToShape(extractor.getTextUnordered(), rect);
- Parameters:
all
- a Collection of Text objectsshape
- the Shape to trim the text to- Returns:
- a new Collection of Text items where every item is completely inside the specified shape
- Since:
- 2.11.8
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-