We have a database that has decompiled data versions of PDF files stored as blobs.
The old method to retrieve the information was to grab the blob, compile the file on the local disk, and then use process.start to launch the new .pdf file that was created.
I guess I am looking for a class that can accept the decompile PDF data, turn it into a compiled PDF and show the end results without having to save the file to the local disk.
Anyone have any suggestions?
thanks.
You could just create the stream and send that into a Document Viewer control for PDF. There are tons of PDF Viewer controls, as long as they support a DataStream you should be fine. I'd let the process compile the PDF File into memory as a File Stream and send it to the PDF viewer. I have done the same thing but to a Microsoft format like xps, and doc but as long as the viewer supports a file stream you should have no problem.
This pdf viewer has a cost, but it might help: http://www.gnostice.com/nl_article.asp?id=109 the example they show goes by filename but its possible it might support the data stream method. Most views do.
Run through all the compiled .pdfs with your old method and store them somewhere.
Related
I am working on vb.net application where I wanted to create and read a file. File will have specific extension for ex. .abcb the way I want my application to work is:
can create a file with .abcd extension
should read .abcd files only(and also application created files only so altered extension shouldn't be working)
.abcd files should show some garbage data when open in any other application(ex. word, notepad any image viewer etc.)
Now my application does 1,2(partly) step, i.e. it creates a file and load data also, it reads .abcd files only(not the altered files)
but created file can be read by other software's also.I tried searching a lot but have not found anything and don't know where to start.
Any help is appreciated!
if you don't want other programs to be able to read the content of your file then your going to have to mask it in some way, which is usually done with encryption.
assuming your not too worried about the key being compromised, the easiest way to accomplish this would be to generate a key with something like System.Security.Cryptography and use that key to encyrpt everything you send to the file and everything you read from it.
as for making your own file extension, you can make the extension of a file whatever you want when you make it:
Dim fs As FileStream = File.Create("/path/to/file/filename" & ".abcd")
the only thing that the extension does is tell the OS what progam to use when opening a file by default, which will probably be notepad since your making your own extension
I have a text file. Now I have changed its file type from .txt to .abc. My VB.NET program loads the text into textboxes from that file. After changing the file type, however, other apps like NotePad and Word are able to open and read my .abc file.
Is there any way that only my application will be able to open/read from the file and no other app would be able to do so? What I mean is, suppose I have a PhotoShop document .psd file, no other app, rather that photoshop itself, can open it. How do I make my file unreadable by other apps?
There is no way to prevent an app that you don't develop from opening any file. The extensions are just there for helping us humans, and maybe a bit for the computer to know the default app you select for an extension.
Like you said, a .txt file can be opened by many many apps. You can open a .txt file with Notepad, Firefox, VSCode, and many others.
Same way, a .psd file can be opened by many many apps. You can open that .psd file with Photoshop, but also Notepad, Firefox, and VSCode, and probably the same apps as above.
The difference is which apps can read and understand the file.
In order to make a file not understandable by other apps, you need to make it into a format that cannot recognize, because you planned it "in secret".
Like Visual Vincent said above, you could encrypt the file in a way, or you can have a binary file, that basically only your app knows know to understand.
Since you dont own the app you want the file to be understood by, then you either have to accept that it can be opened by any app that can open files, or you can try to encrypt the file outside the app, or like zipping it with a password, and then decrypting or unzipping when you want to use it.
Firstly, any file can be read unless it is still open by a particular process or service. Even PhotoShop files can be 'read' by NotePad - try it!
So, an attempt at my first answer...
You can try a couple of methods to prevent opening the file, for instance, applying a file lock. As an example, SQL Server .mdf files are locked by the SQL Server service. This happens because the files are maintained in an open state, however; your application would have to remain running to keep these files open. Technically, though, the files can still be copied.
Another way is to set the hidden attribute for the file. This hides the file from the less savvy users, but it will be displayed if the user show's hidden files.
And my second answer: You refer to the format of files by saying only PhotoShop can read or write its own files (not true, but I know what you're saying).
The format of the file must be decided by yourself. You must determine how you are going to store the data that you output from your application. It looks like you have been attempting to write your application data into a text file. Perhaps you should try writing to binary files instead. Binary files, while not encrypted, as suggested by Visual Vincent in the comments to your question, still provide a more tailored approach to storing your data.
Binary files write raw binary data instead of humanised text. For instance, if you write an integer to the file it will appear as a string of four bytes, not your usual 123456789 textual format.
So, you really need to clarify what data you want to write to the file, decide on a set structure to your file (as you also have to be able to read it back in to your application) and then be able to write the information.
I tried to find proper services for generating PDF files in Liferay, however I have found only class PDFProcessorUtil. How to use it to generate PDF file? How to save the generated file then? I think I should use
DLAppLocalServiceUtil.addFileEntry to save file into Liferay storage.
Liferay's PDF-conversion works by converting documents in the document library and offering them for download - this is implemented through Open Office. Install Open Office or Libre Office, run it in server mode and configure Liferay to use it, then you can choose to select downloads as PDF. The HTML format has a few limitations, as it can include so many external resources, so I'm not sure what your result will be.
If you're generating the HTML output yourself, you might want to consider any other (Liferay-independent) means of generating PDF, as you might not need to upload your files to the Document Library (e.g. if you're generating reports on the fly and just want the generator result to be PDF, but not store them). If this is what you need, you can use any pdf converter library you want - Liferay does not limit you in your choice.
You can also generate the PDFs from the serve resource phase of a portlet.
You put a button or a link somewhere, and when you click on it, you download the PDF.
In this simple example, the PDF is generated from a Freemarker template that generates an HTML that is converted to PDF:
https://github.com/roclas/pdfUtil
i'm trying to create a PDF report object that contains some PDF files saved as BLOB records into my DB.
At this point I'm able to embed images only...
How can I "append" other kinds of files into my genexus-report, such as PDF files?
Any suggestion will be appreciated
Client: GXEv2 - U5,
Environment: Java
I know it's possible to append others GX reports in your report by calling them.
However, i think there is no way to append a PDF file.
I'm looking for a way to convert a PDF document into multiple ics files that staff can use to add their fortnight roster to their smart phone calendars or outlook calendar on their desktops. The information required to create the multiple files would be pulled from the PDF by searching for selected initials from each column then referencing data from the same row as the initials. Is their a particular order I need the data to appear in the ics file to allow it to import to a smartphone calendar??
You can search for pdf APIs for more details in handling a pdf using programmatically.
and here are some online converters that could help. They convert a pdf into word
http://www.pdftoword.com/success.aspx
http://www.pdfescape.com/account/?expired
However, reconstructing structured data from PDF is not trivial because a program has to deduct the semantics in the layout. So most programs can only restore scattered data from a pdf.
I've done this with PERL and windows Adobe PDF viewer to highlight all the text in the PDF and cut and paste to a text file. As the previous answer said, you have to write PERL (or any other text processing language) to pick out the format of the PDF you have. Then you can print it with PERL to csv or to ical or whatever format you want. I've shared my code on github.com. I'm not sure if you know GIT, but send me a private message if you want me to send the PERL code outside of GIT.
The PDF's I've converted are here:
http://recplexonline.com/sports/hockey/old-geezers-hockey-35
The Git hub of my PERL code and the input files I used are here:
https://github.com/jdeltoft/PdfParse
It's pretty ugly perl, sorry for that. But it works. I'll try to clean it up soon.