I am working on a Spring REST service based web application (UI is based on HTML5, backbone.js). The actual requirement is, an uploaded document (could be any document like excel, word, ppt, pdf etc) requires an preview option using which an user can view the document in the browser (user may or may not have office installed).
My idea is to convert the documents into images and display them to the user. On searching, i found multiple ways to convert a PDF to image but not much ODT to image (Note: I am looking for an open source). JODConverter, docx4j can be used to convert the documents to pdf. Then I can convert these PDFs to images. But is this the right way. Is there any other efficient way to achieve the same. Please suggest and point me to the right direction.
Thanks in advance.
Gopi
Yes, you won't do any better than .docx to .pdf to image. You really need a stable workflow, and this is as good as you'll find for this purpose, unless you're running on a Microsoft server and you have access to the official Microsoft Office stuff.
For previews, docx4j or similar will do just fine. Not everything converts perfectly, but it should be fine for a preview.
Related
I am new to java, I have to read a PDF, Open Office or MS Word file and make changes in the file and render as PDF document on my web page. Please someone tell me which of these file's API or SDK is easy to use and also tell me best SDK for this. So I can read, Update and render easily. file also contains Table but there is no image.
We use Apache POI to read Microsoft Office files. There are many libraries for PDF in Java. iText is something I have used. Once you pick the tools, do a selective search on Stack Overflow. There are plenty of discussions around these tools.
Depending on the types of updates you are doing, modifying PDF is going to be a problem - it's not intended for editing. You might have to find some way of converting the PDF to something first, then edit. Depending on the types of changes you want to make and the documents you are working from even editing DOC and Writer files is going to be tricky. They are all different formats.
As Jayan mentioned, iText and POI may help you a little. OpenOffice Writer documents can be edited by unzipping then modifying the XML or using the UNO API. Word documents can be editied by using MS Office automation (bad idea), converting to OpenOffice first then editing, or if DOCX, unzipping and processing the XML.
Good luck.
i've been searching on the internet on how to convert a HTML page into a PDF file using Java. i found a lot of pointers, and in short, they don't work or are too difficult to implement. i also downloaded a commercial product, pdf4ml; the API is something i'd be happy to work with, except that when i crawled a simple page on wikipedia, i get a out of memory error (setting Xmx to 1024 M). in some approaches, they suggest converting HTML -> XHTML -> FO -> PDF. however, i am getting a lot of exceptions for the XHTML-to-FO XLS file; and reading the documentations, it's not something that i have enough time to understand right now.
here are my questions/concerns.
1. is there another cohesive API out there that will easily convert HTML to PDF (commercial or not)?
2. is there a way i can simply capture a HTML page and store it as a single file. this approach would be similar to using internet explorer's way of saving a web page as a web archive (single file, MHT format)?
any help is appreciated. (btw, i know this question has been asked repeatedly, but in addition to the original spirit of the question, i'm opened to other ways). thanks.
Try wkhtmltopdf, which is using WebKit. Another option (I'm using that currently) is using OpenOffice (remote controlled via macros).
you may use iText open source Java lib for that, and read this
or use YaHPConverter open source Java lib.
or do this whith help of icepdf popular open source lib
or use pd4ml, but it not free, only trial.
or use this, and this is man for it.
My 2 cents using opensource tools:
You can use either Capture screenshots with Selenium or WebDriver to save html page's screenshot in an image file from your Java code. And once you have image file you can convert it to pdf again from your Java code.
EDIT:
It seems you can do all that in 1 step using itext Html to Pdf
I am not sure but you could Try
1) cobra html rendering engine http://lobobrowser.org/cobra.jsp
2) htmleditorkit -- part of jdk
3) JWebPane
Use the rendering kit to parse and render html. The rendered out put is a swing component. Swing component can be used by itext to generate pdf file out put
You can try out Pdfcrowd. It is an easy to use commercial online API with many options and with support for Java.
It can create PDF either from web pages or raw HTML code.
How can i read content of scanned pdf file in java/jsp or in javascript, can you tell how to achieve this with developing code?
advance thanks for reply
You can convert the scanned PDF to a image using GhostScript and then feed it to an OCR engine, such as Tesseract. Take a look at VietOCR for an example implementation.
What you are trying to do (I think) is use OCR to extract text from a image PDF produced by a scanner. Java is probably the best for doing this. There are a number of options for doing this, depending on whether you are prepared to pay for software to do this. Google for Java (or Javascript), PDF and OCR.
IMO, this task is not something that should be done in a JSP. JSPs are best for rendering results ... not for generating them in the first place.
Actually, I am working on the same project at the moment, I am doing this in the following steps and the result works well.
User upload a scanned pdf to PDFUploader servlet, returns a server side file name to front end, which indicates upload is successful.
Front end uses this file name and default page 0 to ask PDFReader servlet to retrieve the first page of pdf file and display is at the front end, you can convert this pdf to a image for use an iframe to have the embedded pdf reader.
Front end uses this file name and default page 0 to ask OCRServlet to perform OCR. I am using WeOCR and tesseract as my OCR engine in an Apache http server. I have modified some parts of the submit.cgi in WeOCR server since I know what types of the format that the WeOCR server will receive. I still have some problems while I convert the scanned pdf to an image (I am using pdfbox )
Google for anything OCR related,
best bet will be to use existing libraries like http://asprise.com/product/ocr/index.php?lang=java
I'm using a JTree to browse the content of a folder and I want that when a user click on a file, the software shows a preview of it (a screenshot of its first page).
The files are mostly Office documents and PDF.
I manage to do it for PDF file using a module downloaded from Sun, but I'd like to know if there is a way to do it using any software (JARs preferably) or even the built-in Windows API.
I was thinking of converting the file to PDF then do a preview of this PDF but this isn't optimal.
Any ideas ?
I've got the similar problem and the best I found after couple of days of googling is following.
Alfresco has the same problem and resolved it with :
An open office which runs in server mode (socket) and all the office documents are sent by alfresco to open office in order to convert them in PDF
Those PDF are converted to .swf viewer thanks to SWFTOOLS
This .swf is integrated in the HTML
For images, it uses ImageMagick to create small version of the file I suppose
Personnaly, I will try to implement it this way :
Converting office documents to PDF thanks to open office in socket mode
Transform the first page of the PDF into a PNG thanks to JPedal library (the LGPL version)
Diplay that PNG to the end user
For images I would perhaps use ImageMagick too ... but for now, I'm using Seam Image.scaleToFit API
I had the same problem too and stumbled over this thread. Starting with the solution from Anthony I am using Libre Office in socket mode to convert office documents directly to a PNG. Unfortunately this isn't posible from PDF's. Here is a good overview which ways are possible.
unoconv --connection 'socket,host=127.0.0.1,port=2220,tcpNoDelay=1;urp;StarOffice.ComponentContext' -f png -e PageRange=1 your_file_name.extension
Little reference to start Libre Office in socket mode: click me
I asked this a long time ago: solution
Is there any free Java library for extracting text from PDF, that is compatible with Google Application Engine?
I've read about PDFJet, but it can't read PDF, can it?
Is there perhaps other way how to extract text from PDF? I tried http://www.pdfdownload.org/, unfortunately they don't handle non-English characters correctly.
iText now has a text parsing module (I'm one of the parser authors). See the com.itextpdf.text.pdf.parser.PdfContentReaderTool class for an example of how to use it.
PdfBox does not run on GAE. It uses not-allowed java classes.
(GAE only permits these http://code.google.com/appengine/docs/java/jrewhitelist.html)
I have partially modified a very old version of PdfBox (0.7.3) to be GAE complaiant. Now I'm able to extract text from PDF (whole page or rectangular area). I only modified a minumum part of the pdf text extraction and not the whole PdfBox. :)
The idea was to remove refences to java.awt.retangle & C. using my own "rectangle" class.
More info: http://fhtino.blogspot.com/2010/04/pdfbox-text-extration-gae.html
I modified the latest (1.8.0-Snapshot) version to run on Google AppEngine. Had to disable one Unit-Test, but it runs fine for simple text extraction.
Following the simple try-fail-fix approach i had to modify 5 files in total. Pretty doable.
You'll also have to explicitly use a RandomAccessBuffer, like Fabrizio explained.
For the extra lazy, heres the compiled jar, dependencies for text extraction, and the patch. Note that it might not work for every usecase (i.e. rectangle based extraction). Used it to extract text of a whole page.
https://docs.google.com/folder/d/0B53n_gP2oU6iVjhOOVBNZHk0a0E/edit
I know there is http://pdfbox.apache.org/index.html
Apache PDFBox is an open source Java
PDF library for working with PDF
documents. This project allows
creation of new PDF documents,
manipulation of existing documents and
the ability to extract content from
documents.
but I've never tested it.
Last month, I'd just finished extracting text from pdf file in my project. I used XPDF tool for getting text, and text coordinates, but I used it in Xcode (Objective-C). This tool was open source, written by C++, and able to be encoded in many language. However, I didn't know whether XPdf would be work on your java, or not. Anyway, You can try this tool.