How to replace text in pdf using java - java

What I am trying to achieve is to replace a text in pdf file. I have the following code:
PdfReader reader = new PdfReader("test.pdf");
PdfDictionary dict = reader.getPageN(1);
PdfObject object = dict.getDirectObject(PdfName.CONTENTS);
if (object instanceof PRStream)
{
PRStream stream = (PRStream) object;
byte[] data = PdfReader.getStreamBytes(stream);
System.out.println(new String(data));
stream.setData(new String(data).replace("application", "HELLO WORLD").getBytes());
}
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream("test-output.pdf"));
stamper.close();
reader.close();
When I trying to print out to see the data (System.out.println(new String(data))), "application" is showing as "ap)-4(plica)-3(tion", that's the reason why I failed to replace the text, any idea or other method that can achieve what I trying to achieve?

You will not be able to do this with iText.
Believe me, this is one of the most frustrating discoveries about PDFs: you can build them with iText, but you cannot go back later and replace text with something else, as you have in your example.
There really is not much you can do about it. Once text is there, you can't modify it.
All that notwithstanding, you can usually ADD new content (text, images, etc.) to an existing PDF. So... if you can alter the universe slightly and create a PDF with empty space in the correct size, you can go back later and use the PdfStamper class to "stamp" on another layer of graphical content.
More on this can be found in the iText documentation, and in this fine question:
How to add Content to a PDF using iText PdfStamper

Related

Itext error IllegalArgumentException: Tagging must be set before opening the document

I am using itext to fill a template pdf, but I want to add tag to the template pdf and to the elements that I am trying to fill into it.
The first step that I made is trying to insert tag for the element that I am trying to insert into, here my code:
PdfReader reader = new PdfReader("myTemplatepath");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfStamper stamper = new PdfStamper(reader, baos);
PdfWriter writer = stamper.getWriter();
writer.setTagged(); //Make document tagged
But when I am using writer.setTagged() I have the following error:
java.lang.IllegalArgumentException: Tagging must be set before opening
the document
I saw, in this Topic that the problem is that PdfStamper doesn't support tagging,and the best solution is to create a new PDF and tagged it so my question is :
Since the topic is from 2007, there is any new implementation about this?
If not, what is the best way to doing so? The template that I have is not so simple and It has editable elements ( that i fill automaticatily).

Add watermark to pdf java iText

I want to add a image or text watermark to pdf file. I found some examples online, but my case is a little bit different.
I have an existing pdf template which is already populated with dynamic data and converted to byte[]. This generated bytes are later exported to pdf.
I would like to add the watermark to that generated bytes.
Something like:
byte[] addWatermark(byte[] generatedBytes){
byte[] bytesWithWatermark;
//add watermark to bytes
return bytesWithWatermark;
}
I just can't seem to figure out how to do this with iText.
You say you already have examples for applying watermarks using iText. As you already have a PDF, you should use code from an example that adds watermarks to existing PDFs. This should be an example that works with a PdfReader / PdfStamper pair, e.g. those here, which all have the structure
PdfReader reader = new PdfReader(SOME_SOURCE);
PdfStamper stamper = new PdfStamper(reader, SOME_TARGET_STREAM);
[... add watermark to all pages in stamper ...]
stamper.close();
reader.close();
To make these example fit into your addWatermark method, simply use your byte[] instead of SOME_SOURCE and a ByteArrayOutputStream instead of SOME_TARGET_STREAM:
byte[] addWatermark(byte[] generatedBytes) {
try (ByteArrayOutputStream target = new ByteArrayOutputStream()) {
PdfReader reader = new PdfReader(generatedBytes);
PdfStamper stamper = new PdfStamper(reader, target);
[... add watermark to all pages in stamper ...]
stamper.close();
reader.close();
return target.toByteArray();
}
}
PS As you used only the tag itext and not the tag itext7, I assumed you were looking for a solution for iText 5.5.x. But the same principle as applied here, i.e. using your byte[] as source argument and a ByteArrayOutputStream as target argument, will also allow you to make iText 7.x examples fit into your method frame.

How can I insert a word in a sentence of a PDF content in Java?

I want to add a word in a sentence of a PDF content.
For example:
This is a sample content.
I want to insert a word in that content like this output.
This is a nice sample content.
This is a sample code for itextPdf that I found in the internet. Assumed that the content already exists and we want to modify it by adding a text in a sentence.
try {
//Create PdfReader instance.
PdfReader pdfReader =
new PdfReader(SRC);
//Create PdfStamper instance.
PdfStamper pdfStamper = new PdfStamper(pdfReader,
new FileOutputStream(DEST));
//Create BaseFont instance.
BaseFont baseFont = BaseFont.createFont(
BaseFont.TIMES_ROMAN,
BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
//Get the number of pages in pdf.
int pages = pdfReader.getNumberOfPages();
System.out.println(pdfStamper.getOverContent(1));
//Iterate the pdf through pages.
for(int i=1; i<=pages; i++) {
//Contain the pdf data.
PdfContentByte pageContentByte =
pdfStamper.getOverContent(i);
pageContentByte.setFlatness(89);
pageContentByte.beginText();
//Set text font and size.
pageContentByte.setFontAndSize(baseFont, 14);
pageContentByte.setTextMatrix(50, 720);
//Write text
pageContentByte.setWordSpacing(12);
pageContentByte.showText("hello world");
pageContentByte.endText();
}
//Close the pdfStamper.
pdfStamper.close();
System.out.println("PDF modified successfully.");
} catch (Exception e) {
e.printStackTrace();
}
I tried itextPdf and PdfBox but neither of them would work.
I can get the objects in the pdf document using PDFStreamParser of pdfbox.
PDFOperator{Td}, COSArray{[COSString{Name }, COSFloat{163.994}, COSString{____________________________________________________}, COSFloat{-8.03223}, COSString{________________________________________________________}]}, PDFOperator{TJ}, COSInt{19}, PDFOperator{TL}, PDFOperator{T*}, COSArray{[COSString{T}, COSInt{36}, COSString{itle}, COSFloat{0.997925}, COSString{ }, COSFloat{-94.9982}, COSString{_____________________________________________________________________________________________________________}]}, PDFOperator{TJ}, PDFOperator{T*}, COSArray{[
How can I implement a code that inserts a text?
Not.
Pdf is not a wysiwyg format. Internally, it's more like a file containing code. It has instructions for moving around a cursor, and drawing text and graphics at the tip of the cursor.
Then there's the fact that most instructions get packaged into "objects". All objects get placed in a dictionary that uses byte-offsets to reference them.
So inserting anything in a pdf-document will cause problems on 2 levels.
You would mess up the byte-offset of everything in the document
You would need to unscramble all the existing rendering operations to make sense of the document (to derive structure like lines of text, paragraph, etc) so that you can properly re-flow the content after you've inserted something.
Hence my short answer. You can't. And that immediately explains why none of the pdf toolkits you've tried can do it. It's simply an insanely hard task.

Merge PDF with FDF output only PDF

I have a PDF and FDF file and want to merge them into a single PDF. The .pdf has no fields, these are all included in the .fdf file, the contents of the fields also.
I have several solutions found, but these only works when the fields are stored in the pdf.
I would like to use iText with Java.
Does anyone have some demo code how I can solve my problem? Thank you!
Here's some code which only works when the fields are already present in the PDF
PdfReader pdfreader = new PdfReader(pdfInPath);
PdfStamper stamp = new PdfStamper(pdfreader, new FileOutputStream(pdfOutPath));
FdfReader fdfreader = new FdfReader(fdfInPath);
AcroFields form = stamp.getAcroFields();
form.setFields(fdfreader);
stamp.close();

Add named destinations to an existing PDF document with iText

I have a PDF previously created with FOP, and I need to add some named destinations to it so later another program can open and navigate the document with the Adobe PDF open parameters, namely the #namedest=destination_name parameter.
I don't need to add bookmarks or other dynamic content but just some destinations with a name and thus injecting a /Dests collection with names defined in the resulting PDF.
I use iText 5.3.0 and I read the chapter 7 of iText in Action (2nd edition), but still I cannot figure it out how to add the destinations and so use them with #nameddest in a browser.
I'm reading and manipulating the document with PdfReader and PdfStamper. I already know in advance where to put every destination after having parsed the document with a customized Listener and a PdfContentStreamProcessor, searching for a specific text marker on each page.
This is a shortened version of my code:
PdfReader reader = new PdfReader(src);
PdfStamper stamper = new PdfStamper(reader, new BufferedOutputStream(dest));
// search text markers for destinations, page by page
for (int i=1; i<reader.getNumberOfPages(); i++) {
// get a list of markers for this page, as obtained with a custom Listener and a PdfContentStreamProcessor
List<MyDestMarker> markers = ((MyListener)listener).getMarkersForThisPage();
// add a destination for every text marker in the current page
Iterator<MyDestMarker> it = markers.iterator();
while(it.hasNext()) {
MyDestMarker marker = it.next();
String name = marker.getName();
String x = marker.getX();
String y = marker.getY();
// create a new destination
PdfDestination dest = new PdfDestination(PdfDestination.FITH, y); // or XYZ
// add as a named destination -> does not work, only for new documents?
stamper.getWriter().addNamedDestination(name, i /* current page */, dest);
// alternatives
PdfContentByte content = stamper.getOverContent(i);
content.localDestination(name, dest); // doesn't work either -> no named dest found
// add dest name to a list for later use with Pdf Open Parameters
destinations.add(name);
}
}
stamper.close();
reader.close();
I also tried creating a PdfAnnotation with PdfFormField.createLink() but still, I just manage to get the annotation but with no named destination defined it does not work.
Any solution for this? Do I need to add some "ghost" content over the existing one with Chunks or something else?
Thanks in advance.
edit 01-27-2016:
I recently found an answer to my question in the examples section of iText website, here.
Unfortunately the example provided does not work for me if I test it with a pdf without destinations previously defined in it, as it is the case with the source primes.pdf which already contains a /Dests array. This behaviour appears to be consistent with the iText code, since the writer loads the destinations in a map attribute of PdfDocument which is not "inherited" by the stamper on closing.
That said, I got it working using the method addNamedDestination() of PdfStamper added with version 5.5.7; this method loads a named destination in a local map attribute of the class which is later processed and consolidated in the document when closing the stamper.
This approach reaised a new issue though: the navigation with Pdf Open Parameters (#, #nameddest=) works fine with IE but not with Chrome v47 (and probably Firefox, too). I tracked the problem down to the order in which the dests names are defined and referenced inside the document; the stamper uses a HashMap as the container for the destinations, which of course does not guarantee the order of its objects and for whatever reason Chrome refuse to recognise destinations not listed in "natural" order. So, the only way I got it to work is replacing the namedDestinations HashMap with a natural-ordered TreeMap.
Hope this help others with the same issue.
I 've been in the same need for my project previously. Had to display and navigate pdf document with acrobat.jar viewer. To navigate i needed the named destinations in the pdf. I have looked around the web for a possible solution, but no fortunate for me. Then I this idea strikes my mind.
I tried to recreate the existing pdf with itext, navigating through each page and adding localdestinations to each page and i got what I wanted. below is the snip of my code
OutputStream outputStream = new FileOutputStream(new File(filename));
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
PdfContentByte cb = writer.getDirectContent();
PdfOutline pol = cb.getRootOutline();
PdfOutline oline1 = null;
InputStream in1 = new FileInputStream(new File(inf1));
PdfReader reader = new PdfReader(in1);
for (int i = 1; i <= reader.getNumberOfPages(); i++)
{
document.newPage();
document.setMargins(0.0F, 18.0F, 18.0F, 18.0F);
PdfImportedPage page = writer.getImportedPage(reader, i);
document.add(new Chunk(new Integer(i).toString()).setLocalDestination(new Integer(i).toString()));
System.out.println(i);
cb.addTemplate(page, 0.0F, 0.0F);
}
outputStream.flush();
document.close();
outputStream.close();
Thought it would help you.

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