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PDFUtil: How to compare 2 pdf file with not same format and highlight the difference

I want to compare 2 file PDF and now I am using PdfUtil library.
But I have a problem,PdfUtil still works like expected if files have a same format.If not,The result image will highlight everything and I can't see the difference of content between 2 file.
So,How can I compare only content like TEXT_Mode but still get result image with highlight the difference like VISUAL_MODE
Thanks .
This is my simple code
public static void main(String[] args) throws IOException {
String result ="/Users/abc/Downloads/Test";
String pdf1 = "/Users/abc/Downloads/pdf1.pdf";
String pdf2 = "/Users/abc/Downloads/pdf2.pdf";
PDFUtil pdfUtil = new PDFUtil();
pdfUtil.setCompareMode(CompareMode.VISUAL_MODE);
pdfUtil.highlightPdfDifference(true);
pdfUtil.setImageDestinationPath(result);
boolean abc =pdfUtil.compare(pdf1,pdf2);
System.out.print(abc);
}

You could try https://github.com/lumpchen/xdiff.ncc, a pdf compare tool based on pdfbox.

ItextSharp - diacritic chars

i reading pdf documents via ItextSharp library.
But these documents is in Czech language which use diacritic (ř ě ž š č etc.)
How I can read this chars? Any idea? Or, is some solution for replacing this chars for normal r e z s c ?
This is code in my method. Thanks
PdfReader reader = new PdfReader("M:/ShareDirs_KSP/RDM_Debtors/DMS_PROD/" + src);
// we can inspect the syntax of the imported page
String text = new String();
for (int page = 1; page <= 1; page++) {
text += PdfTextExtractor.getTextFromPage(reader, page);
}
reader.close();

I have written a small proof of concept that parses the file czech.pdf. This file contains several characters with diacritics. It was created in answer to the following question: Can't get Czech characters while generating a PDF
The text is stored in the file twice: once using a simple font, once using a composite font. In my proof of concept (named ParseCzech), I parse this PDF to a file encoded using UTF-8 (UNICODE):
public void parse(String filename) throws IOException {
PdfReader reader = new PdfReader(filename);
FileOutputStream fos = new FileOutputStream(DEST);
for (int page = 1; page <= 1; page++) {
fos.write(PdfTextExtractor.getTextFromPage(reader, page).getBytes("UTF-8"));
}
fos.flush();
fos.close();
}
The result is the file czech.txt:
As you can see from the screen shot, the text is extracted correctly (but make sure that the viewer you use knows that the file is encoded as UTF-8, otherwise you may see strange characters instead of the actual text).
Note that some PDFs do not allow text to be extracted correctly. This is explained in the following video: http://www.youtube.com/watch?v=wxGEEv7ibHE
Please share your PDF so that people on StackOverflow can check whether you don't succeed to extract text because of an error in your code, or whether you don't succeed because the PDF doesn't allow you to extract the text.

iText mergeFields in PdfCopy creates invalid pdf

I am working on the task of merging some input PDF documents using iText 5.4.5. The input documents may or may not contain AcroForms and I want to merge the forms as well.
I am using the example pdf files found here and this is the code example:
public class TestForms {
#Test
public void testNoForms() throws DocumentException, IOException {
test("pdf/hello.pdf", "pdf/hello_memory.pdf");
}
#Test
public void testForms() throws DocumentException, IOException {
test("pdf/subscribe.pdf", "pdf/filled_form_1.pdf");
}
private void test(String first, String second) throws DocumentException, IOException {
OutputStream out = new FileOutputStream("/tmp/out.pdf");
InputStream stream = getClass().getClassLoader().getResourceAsStream(first);
PdfReader reader = new PdfReader(new RandomAccessFileOrArray(
new RandomAccessSourceFactory().createSource(stream)), null);
InputStream stream2 = getClass().getClassLoader().getResourceAsStream(second);
PdfReader reader2 = new PdfReader(new RandomAccessFileOrArray(
new RandomAccessSourceFactory().createSource(stream2)), null);
Document pdfDocument = new Document(reader.getPageSizeWithRotation(1));
PdfCopy pdfCopy = new PdfCopy(pdfDocument, out);
pdfCopy.setFullCompression();
pdfCopy.setCompressionLevel(PdfStream.BEST_COMPRESSION);
pdfCopy.setMergeFields();
pdfDocument.open();
pdfCopy.addDocument(reader);
pdfCopy.addDocument(reader2);
pdfCopy.close();
reader.close();
reader2.close();
}
}
With input files containing forms I get a NullPointerException with or without compression enabled.
With standard input docs, the output file is created but when I open it with Acrobat it says there was a problem (14) and no content is displayed.
With standard input docs AND compression disabled the output is created and Acrobat displays it.
Questions
I previously did this using PdfCopyFields but it's now deprecated in favor of the boolean flag mergeFields in the PdfCopy, is this correct? There's no javadoc on that flag and I couldn't find documentation about it.
Assuming the answer to the previous question is Yes, is there anything wrong with my code?
Thanks

We are using PdfCopy to merge differents files, some of files may have fields. We use the version 5.5.3.0. The code is simple and it seems to work fine, BUT sometimes the result file is impossible to print!
Our code :
Public Shared Function MergeFiles(ByVal sourceFiles As List(Of Byte())) As Byte()
Dim document As New Document()
Dim output As New MemoryStream()
Dim copy As iTextSharp.text.pdf.PdfCopy = Nothing
Dim readers As New List(Of iTextSharp.text.pdf.PdfReader)
Try
copy = New iTextSharp.text.pdf.PdfCopy(document, output)
copy.SetMergeFields()
document.Open()
For fileCounter As Integer = 0 To sourceFiles.Count - 1
Dim reader As New PdfReader(sourceFiles(fileCounter))
reader.MakeRemoteNamedDestinationsLocal()
readers.Add(reader)
copy.AddDocument(reader)
Next
Catch exception As Exception
Throw exception
Finally
If copy IsNot Nothing Then copy.Close()
document.Close()
For Each reader As PdfReader In readers
reader.Close()
Next
End Try
Return output.GetBuffer()
End Function

Your usage of PdfCopy.setMergeFields() is correct and your merging code is fine.
The issues you described are because of bugs that have crept into 5.4.5. They should be fixed in rev. 6152 and the fixes will be included in the next release.
Thanks for bringing this to our attention.

Its just to say that we have the same probleme : iText mergeFields in PdfCopy creates invalid pdf. So it is still not fixed in the version 5.5.3.0

ghost4j class cast exception during joining two PostScripts

I am trying to join two PostScript files to one with ghost4j 0.5.0 as follows:
final PSDocument[] psDocuments = new PSDocument[2];
psDocuments[0] = new PSDocument();
psDocuments[0].load("1.ps");
psDocuments[1] = new PSDocument();
psDocuments[1].load("2.ps");
psDocuments[0].append(psDocuments[1]);
psDocuments[0].write("3.ps");
During this simplified process I got the following exception message for the above "append" line:
org.ghost4j.document.DocumentException: java.lang.ClassCastException:
org.apache.xmlgraphics.ps.dsc.events.UnparsedDSCComment cannot be cast to
org.apache.xmlgraphics.ps.dsc.events.DSCCommentPage
Until now I have not made to find out whats the problem here - maybe some kind of a problem within one of the PostScript files?
So help would be appreciated.
EDIT:
I tested with ghostScript commandline tool:
gswin32.exe -dQUIET -dBATCH -dNOPAUSE -sDEVICE=pswrite -sOutputFile="test.ps" --filename "1.ps" "2.ps"
which results in a document where 1.ps and 2.ps are merged into one(!) page (i.e. overlay).
When removing the --filename the resulting document will be a PostScript with two pages as expected.

The exception occurs because one of the 2 documents does not follow the Adobe Document Structuring Convention (DSC), which is mandatory if you want to use the Document append method.
Use the SafeAppenderModifier instead. There is an example here: http://www.ghost4j.org/highlevelapisamples.html (Append a PDF document to a PostScript document)

I think something is wrong in the document or in the XMLGraphics library as it seems it cannot parse a part of it.
Here you can see the code in ghost4j that I think it is failing (link):
DSCParser parser = new DSCParser(bais);
Object tP = parser.nextDSCComment(DSCConstants.PAGES);
while (tP instanceof DSCAtend)
tP = parser.nextDSCComment(DSCConstants.PAGES);
DSCCommentPages pages = (DSCCommentPages) tP;
And here you can see why XMLGraphics may bre sesponsable (link):
private DSCComment parseDSCComment(String name, String value) {
DSCComment parsed = DSCCommentFactory.createDSCCommentFor(name);
if (parsed != null) {
try {
parsed.parseValue(value);
return parsed;
} catch (Exception e) {
//ignore and fall back to unparsed DSC comment
}
}
UnparsedDSCComment unparsed = new UnparsedDSCComment(name);
unparsed.parseValue(value);
return unparsed;
}
It seems parsed.parseValue(value) has thrown an exception, it was hidden in the catch and it returned an unparsed version ghost4j didn't expect.

Java Apache FileUtils readFileToString and writeStringToFile problems

I need to parse a java file (actually a .pdf) to an String and go back to a file. Between those process I'll apply some patches to the given string, but this is not important in this case.
I've developed the following JUnit test case:
String f1String=FileUtils.readFileToString(f1);
File temp=File.createTempFile("deleteme", "deleteme");
FileUtils.writeStringToFile(temp, f1String);
assertTrue(FileUtils.contentEquals(f1, temp));
This test converts a file to a string and writtes it back. However the test is failing.
I think it may be because of the encodings, but in FileUtils there is no much detailed info about this.
Anyone can help?
Thanks!
Added for further undestanding:
Why I need this?
I have very large pdfs in one machine, that are replicated in another one. The first one is in charge of creating those pdfs. Due to the low connectivity of the second machine and the big size of pdfs, I don't want to synch the whole pdfs, but only the changes done.
To create patches/apply them, I'm using the google library DiffMatchPatch. This library creates patches between two string. So I need to load a pdf to an string, apply a generated patch, and put it back to a file.

A PDF is not a text file. Decoding (into Java characters) and re-encoding of binary files that are not encoded text is asymmetrical. For example, if the input bytestream is invalid for the current encoding, you can be assured that it won't re-encode correctly. In short - don't do that. Use readFileToByteArray and writeByteArrayToFile instead.

Just a few thoughts:
There might actually some BOM (byte order mark) bytes in one of the files that either gets stripped when reading or added during writing. Is there a difference in the file size (if it is the BOM the difference should be 2 or 3 bytes)?
The line breaks might not match, depending which system the files are created on, i.e. one might have CR LF while the other only has LF or CR. (1 byte difference per line break)
According to the JavaDoc both methods should use the default encoding of the JVM, which should be the same for both operations. However, try and test with an explicitly set encoding (JVM's default encoding would be queried using System.getProperty("file.encoding")).

Ed Staub awnser points why my solution is not working and he suggested using bytes instead of Strings. In my case I need an String, so the final working solution I've found is the following:
#Test
public void testFileRWAsArray() throws IOException{
String f1String="";
byte[] bytes=FileUtils.readFileToByteArray(f1);
for(byte b:bytes){
f1String=f1String+((char)b);
}
File temp=File.createTempFile("deleteme", "deleteme");
byte[] newBytes=new byte[f1String.length()];
for(int i=0; i<f1String.length(); ++i){
char c=f1String.charAt(i);
newBytes[i]= (byte)c;
}
FileUtils.writeByteArrayToFile(temp, newBytes);
assertTrue(FileUtils.contentEquals(f1, temp));
}
By using a cast between byte-char, I have the symmetry on conversion.
Thank you all!

Try this code...
public static String fetchBase64binaryEncodedString(String path) {
File inboundDoc = new File(path);
byte[] pdfData;
try {
pdfData = FileUtils.readFileToByteArray(inboundDoc);
} catch (IOException e) {
throw new RuntimeException(e);
}
byte[] encodedPdfData = Base64.encodeBase64(pdfData);
String attachment = new String(encodedPdfData);
return attachment;
}
//How to decode it
public void testConversionPDFtoBase64() throws IOException
{
String path = "C:/Documents and Settings/kantab/Desktop/GTR_SDR/MSDOC.pdf";
File origFile = new File(path);
String encodedString = CreditOneMLParserUtil.fetchBase64binaryEncodedString(path);
//now decode it
byte[] decodeData = Base64.decodeBase64(encodedString.getBytes());
String decodedString = new String(decodeData);
//or actually give the path to pdf file.
File decodedfile = File.createTempFile("DECODED", ".pdf");
FileUtils.writeByteArrayToFile(decodedfile,decodeData);
Assert.assertTrue(FileUtils.contentEquals(origFile, decodedfile));
// Frame frame = new Frame("PDF Viewer");
// frame.setLayout(new BorderLayout());
}