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This article mainly explains "Java how to achieve PDF file segmentation and encryption function", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Next let the editor to take you to learn "Java how to achieve the segmentation and encryption of PDF files" bar!

Encrypted file

/ * * encrypted file test * @ from fhadmin.cn * / @ Test public void encryptTest () {try {String filePath = "D:\\ test\\ think about life .pdf like Kaifu Lee"; String password = "1234"; PDDocument document = PDDocument.load (new File (filePath)); StandardProtectionPolicy spp = new StandardProtectionPolicy (password, password,new AccessPermission ()) Document.protect (spp); String newFilePath = "D:\\ test\\ think about life 2.pdf like Kaifu Lee"; document.save (newFilePath); document.close ();} catch (IOException e) {e.printStackTrace ();}}

Cutting file

/ * cut file test * @ from fhadmin.cn * / @ Test public void extractTest () {try {String newFilePath = "D:\\ test\\ think about life 2.pdf like Kaifu Lee"; String password = "1234"; PDDocument document = PDDocument.load (newFile (newFilePath), password) / / read with password / / intercept from the first page to the second page PageExtractor pageExtractor = new PageExtractor (document, 1,2); PDDocument extract = pageExtractor.extract (); extract.save ("D:\\ test\\ think about life free.pdf like Kaifu Lee"); extract.close (); document.close () } catch (IOException e) {e.printStackTrace ();}}

Generate a cover map

/ * cut file test * @ from fhadmin.cn * / @ Test public void createCoverPicTest () {try {String pdfPath = "D:\\ test\\ think about life .pdf like Kaifu Lee"; File file = new File (pdfPath); / / order directory String orderPath = file.getParent () / / converted img directory String bookName = file.getName (). Substring (0Powerfile.getName (). LastIndexOf (".")); String imgPath = orderPath + File.separator + bookName+ ".png"; log.debug ("pdf cover image generated successfully: {}", imgPath); PDDocument pdDocument = PDDocument.load (new File (pdfPath)); PDFRenderer renderer = new PDFRenderer (pdDocument) / * the larger the second bit parameter, the clearer the conversion, and the slower the relative conversion speed * / BufferedImage image = renderer.renderImageWithDPI (0150); ImageIO.write (image, "png", new File (imgPath));} catch (IOException e) {e.printStackTrace ();}}

To sum up, there are plenty of tools now, so you don't have to build your own wheels.

Step-1 goes to the maven warehouse to retrieve the same type of package and compare the heat and the number of users.

Step-2 download the source source code of the corresponding package and take a look at the overall structure of the framework. What are the package and classes in it? I don't know what the class is for. You can take a look at the comments above the class, which are generally relatively simple in English.

Step-3 hands-on unit test for verification.

At this point, I believe that everyone on the "Java how to achieve PDF file segmentation and encryption function" have a deeper understanding, might as well to the actual operation of it! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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