Editing existing pdf in Java

Question

I'm testing Java lib to edit existing pdf but the issue is that a can't load my existing pdf. I have the same result with iText and pdfbox, I can load the file the data seems here(pdf weigh ko) but the pdf created is empty (nothing display).

I'm doing it on a app engine server, with the two lib I can create pdf and display it in my browser with servlet or webservice.

I'm totaly lost, try tons of code but always the same result!

iText with importedPage :

    Document document = new Document();
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    PdfWriter docWriter = PdfWriter.getInstance(document, baos);
    document.open();

    // Load existing PDF
    PdfReader reader = new PdfReader("WEB-INF/pdf.pdf");
    document.newPage();
    PdfImportedPage page = docWriter.getImportedPage(reader, 1);
    PdfPTable table = new PdfPTable(2);
    table.addCell(Image.getInstance(page));
    document.add(table);

    document.close();
    docWriter.close();

pdfbox :

     PDDocument document = new PDDocument();
     PDDocument sourceDocument = PDDocument.load("WEB-INF/pdf.pdf");
     PDPage templatePdfPage = (PDPage)sourceDocument.getDocumentCatalog().getAllPages().get(0);
     document.addPage(templatePdfPage);
     document.save(output);

Answer 1

First of all Get the path Using ServletContext Servlet and using PDFBOx read the pdf file and save the pdf file in /WEB-INF/savedpdffiles/ folder.

Note: Create the folder savedpdffiles under WEB-INF folder.

See The JRE Class White List - A Java App Engine application's access to the classes in the Java standard library (the Java Runtime Environment, or JRE) is limited to the following classes: .

Read and save PDF file in Google AppEngine.

Code:

    PrintWriter printWriter = response.getWriter();
    try {
        ServletContext context = request.getSession().getServletContext();
        String pdffiles = context.getRealPath("/WEB-INF/");

        File readPath = new File(pdffiles);
        if (readPath.exists()) {
            String pdfFile = "04-Request-Headers.pdf"; // read this file to save in savedpdffiles folder
            File savedPath = new File(readPath.getAbsolutePath() +"/savedpdffiles/"); // create savedpdffiles folder under WEB-INF folder

            File readFullPath = new File(readPath.getAbsolutePath() + File.separatorChar + pdfFile);
            if (readFullPath.isFile()) {
                if(!savedPath.exists()) {
                    savedPath.createNewFile();// create new pdf file if not exits
                    printWriter.println( savedPath.getName() +" File created in -> "+ savedPath.getAbsolutePath());
                }

                PDDocument document = new PDDocument();
                PDDocument sourceDocument = PDDocument.load(readFullPath.getAbsolutePath()); // read the pdf file by PDDocument
                PDPage templatePdfPage = (PDPage) sourceDocument.getDocumentCatalog().getAllPages().get(0); // only first page is read out of 13 pages and save the first page.
                document.addPage(templatePdfPage);
                document.save(savedPath + "/" + pdfFile);
                document.close();
                sourceDocument.close();
                printWriter.print(pdfFile + " File saved to this location-> "+ savedPath.getAbsolutePath() + File.separatorChar + pdfFile);
            } else {
                printWriter.println(readFullPath.getName() + " File not exits in -> "+ readFullPath.getAbsolutePath());
            }
        } else {
            printWriter.println("Path not exists -> "+ readPath.getAbsolutePath());
        }
    } catch (Exception e) {
        printWriter.print("Type of Error occured while saving the PDF file -> "+ e.getMessage());
        e.printStackTrace();
    }

You will get below error

Caused by:
          java.lang.NoClassDefFoundError: java.awt.Color is a restricted class. Please see the Google  App Engine developer's guide for more details.
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Answer 2

I find the problem, I'm using maven to build my app. Maven corrumpt my pdf by encoding file (in UTF-8 I think). I found this because I got .p12 file and when I what to read my lib say it was corrumpt file.

The problem now is a try to avoid this but dosn't work. (For the moment I replace file after build)

I try to add this in my pom.xml :

<resources>
        <resource>
            <directory>src/main/webapp/WEB-INF</directory>
            <filtering>false</filtering>
            <excludes>
                <exclude>**/*.pdf</exclude>
            </excludes>
        </resource>
    </resources>

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-resources-plugin</artifactId>
            <configuration>
                <nonFilteredFileExtensions>
                    <nonFilteredFileExtension>pdf</nonFilteredFileExtension>
                </nonFilteredFileExtensions>
            </configuration>
        </plugin>

and something was ambigious in my pom.xml, I doesn't not what it do :

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.3</version>
            <configuration>
                <archiveClasses>true</archiveClasses>
                <webResources>
                    in order to interpolate version from pom into appengine-web.xml
                    <resource>
                        <directory>${basedir}/src/main/webapp/WEB-INF</directory>
                        <filtering>true</filtering>
                        <targetPath>WEB-INF</targetPath>
                    </resource>
                </webResources>
            </configuration>
        </plugin>