PDFUtils

PDFUtils is a Spring bean providing methods for working with PDF documents: merging, encrypting, decrypting, splitting, extracting pages, rotating, filling forms, and rendering pages as images. Static overloads operate on local streams and files; instance methods operate directly on OpenKM repository documents.

Note

PDFUtils is a Spring bean — access it via ContextWrapper.getContext().getBean(PDFUtils.class) or inject it with @Autowired.

Merging

merge (streams)

Description:

Method	Return values	Description
merge(List inputs, OutputStream output)	void	Merges multiple PDF input streams into a single PDF written to the output stream.

Example:

package com.openkm;

import com.openkm.api.OKMDocument;
import com.openkm.util.ContextWrapper;
import com.openkm.util.FileUtils;
import com.openkm.util.PDFUtils;
import com.openkm.util.PathUtils;
import org.apache.commons.io.IOUtils;

import java.io.*;
import java.util.Arrays;

public class Test {

    public static void main(String[] args) {
        File tmp = null;
        try {
            OKMDocument okmDocument = ContextWrapper.getContext().getBean(OKMDocument.class);
            PDFUtils pdfUtils = ContextWrapper.getContext().getBean(PDFUtils.class);

            tmp = FileUtils.createTempFile("pdf");

            try (OutputStream fos = new FileOutputStream(tmp)) {
                pdfUtils.merge(Arrays.asList(
                    okmDocument.getContent(null, "c0984ecf-8d9e-40f8-b5fb-2c83d202bd9d", false),
                    okmDocument.getContent(null, "b3d0af95-076c-4cc4-9b85-bd3e7eb2baa3", false)
                ), fos);
            }

            try (InputStream fis = new FileInputStream(tmp)) {
                okmDocument.createSimple(null, "/okm:root/docMerge.pdf", fis);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            FileUtils.deleteQuietly(tmp);
        }
    }
}

merge (repository documents)

Description:

Method	Return values	Description
merge(String token, List docIds, String dstPath)	String	Merges a list of OpenKM documents (by path or UUID) into a single PDF and stores the result at dstPath in the repository. Non-PDF documents are automatically converted to PDF before merging. Returns the path of the resulting document.

• token: Authentication token.
• docIds: List of repository paths or UUIDs to merge.
• dstPath: Repository path where the merged PDF will be created.

Example:

PDFUtils pdfUtils = ContextWrapper.getContext().getBean(PDFUtils.class);
String result = pdfUtils.merge(null,
    Arrays.asList("/okm:root/doc1.pdf", "/okm:root/doc2.pdf"),
    "/okm:root/merged.pdf");
System.out.println("Merged to: " + result);

Form operations

fillForm

Description:

Method	Return values	Description
fillForm(InputStream input, Map<String, Object> values, OutputStream output)	void	Fills AcroForm fields in a PDF. Fields whose current value contains template expressions (e.g. ${variable}) are processed through the template engine. Fields are also matched by name from the values map. Supports text, checkbox, and date fields. The form is flattened (made non-editable) for any field that is filled.

• input: The PDF input stream.
• values: A map of field name → value for substitution.
• output: The output stream for the filled PDF.

Example:

package com.openkm;

import com.openkm.util.PDFUtils;

import java.io.*;
import java.util.HashMap;
import java.util.Map;

public class Test {

    public static void main(String[] args) {
        try (InputStream is = new FileInputStream("/home/openkm/template.pdf");
             OutputStream os = new FileOutputStream("/home/openkm/filled.pdf")) {

            Map<String, Object> values = new HashMap<>();
            values.put("customerName", "John Smith");
            values.put("invoiceDate", new java.util.Date());
            values.put("approved", "true"); // checkbox

            PDFUtils.fillForm(is, values, os);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

listFormFields

Description:

Method	Return values	Description
listFormFields(String input)	List	Returns the names of all AcroForm fields in the given PDF file path. Returns an empty list if the PDF has no form.

• input: The local file system path to the PDF file.

Example:

List<String> fields = PDFUtils.listFormFields("/home/openkm/template.pdf");
System.out.println("Form fields: " + fields);

Encryption

encrypt (streams)

Description:

Method	Return values	Description
encrypt(InputStream input, String userPassword, String ownerPassword, int permissions, OutputStream output)	void	Encrypts a PDF stream with the given passwords and permissions. Pass null for userPassword to allow opening without a password (restricted by permissions). Pass a non-null userPassword to require a password to open the document.

• permissions: ORed iText permissions constants, e.g. PdfWriter.ALLOW_PRINTING | PdfWriter.ALLOW_COPY.

encrypt (file)

Description:

Method	Return values	Description
encrypt(File input, String userPassword, String ownerPassword, int permissions)	File	Encrypts a PDF file and returns a new temporary file with the encrypted content.

encrypt (repository document)

Description:

Method	Return values	Description
encrypt(String token, String docId, String userPassword, String ownerPassword, int permissions, String dstPath)	void	Encrypts an OpenKM document and stores the result at dstPath. If dstPath already exists the document is checked out and checked in with the new content.

decrypt (streams)

Description:

Method	Return values	Description
decrypt(InputStream input, String ownerPassword, OutputStream output)	void	Decrypts a PDF stream using the owner password and writes the result to the output stream.

decrypt (file)

Description:

Method	Return values	Description
decrypt(File input, String ownerPassword)	File	Decrypts a PDF file and returns a new temporary file with the decrypted content.

isEncrypted (InputStream)

Description:

Method	Return values	Description
isEncrypted(InputStream input)	boolean	Returns true if the PDF stream is encrypted.

isEncrypted (File)

Description:

Method	Return values	Description
isEncrypted(File input)	boolean	Returns true if the PDF file is encrypted.

disableEncryption (streams)

Description:

Method	Return values	Description
disableEncryption(InputStream input, OutputStream output)	void	Removes the encryption flag from a PDF without requiring the owner password, allowing subsequent modification.

disableEncryption (file)

Description:

Method	Return values	Description
disableEncryption(File input)	File	Removes the encryption flag from a PDF file and returns a new temporary file with the result.

Page count

getNumberOfPages (File)

Description:

Method	Return values	Description
getNumberOfPages(File pdf)	int	Returns the number of pages in a local PDF file.

getNumberOfPages (InputStream)

Description:

Method	Return values	Description
getNumberOfPages(InputStream stream)	int	Returns the number of pages in a PDF stream.

getNumberOfPages (repository document)

Description:

Method	Return values	Description
getNumberOfPages(String token, String docId)	int	Returns the number of pages in an OpenKM document. Non-PDF documents are automatically converted to PDF.

Example:

PDFUtils pdfUtils = ContextWrapper.getContext().getBean(PDFUtils.class);
int pages = pdfUtils.getNumberOfPages(null, "e6b61e8d-4bf1-4c37-828f-09ecc34261cc");
System.out.println("Pages: " + pages);

Document rendering

getDocumentInPdf

Description:

Method	Return values	Description
getDocumentInPdf(String token, String docId)	InputStream	Returns the document content as a PDF stream. If the document is not a PDF it is converted to PDF first (using the conversion cache if available). The caller is responsible for closing the stream.

getPageAsImage

Description:

Method	Return values	Description
getPageAsImage(String token, String docId, int page, String size)	File	Renders a single page of a PDF (or convertible) document as a PNG image and returns a temporary file.

• page: The 1-based page number.
• size: The desired image size/resolution descriptor.

Page operations

split (file)

Description:

Method	Return values	Description
split(File file, String baseName, List pages)	File	Splits a PDF file at the given page boundaries and returns a ZIP file containing the resulting parts, each named using baseName.

split (repository document)

Description:

Method	Return values	Description
split(String token, String docId, String dstId, List pages, String baseName)	List	Splits an OpenKM PDF document at the given page boundaries and stores the resulting parts in the dstId folder. Returns the list of created documents.

extract (file)

Description:

Method	Return values	Description
extract(File src, File dst, List pages)	void	Extracts the specified pages from a PDF file and writes the result to dst.

extract (repository document)

Description:

Method	Return values	Description
extract(String token, String docId, String dstId, List pages, String docName)	Document	Extracts the specified pages from an OpenKM PDF document and stores the result as a new document named docName in the dstId folder. Returns the created document.

rotate (file)

Description:

Method	Return values	Description
rotate(File src, File dst, List pages, Integer angle)	void	Rotates the specified pages of a PDF file by the given angle (90, 180, or 270 degrees) and writes the result to dst.

rotate (repository document)

Description:

Method	Return values	Description
rotate(String token, String docId, String dstId, List pages, String docName, Integer angle)	Document	Rotates the specified pages of an OpenKM PDF document and stores the result as a new document in the dstId folder. Returns the created document.

Optimization and conversion

optimize (file)

Description:

Method	Return values	Description
optimize(File pdfIn, File pdfOut)	void	Optimizes a PDF file by linearizing it for fast web viewing and writes the result to pdfOut.

optimize (repository document)

Description:

Method	Return values	Description
optimize(String token, String docId)	void	Optimizes an OpenKM PDF document in place by checking it out, optimizing, and checking it back in.

convertToPdfA

Description:

Method	Return values	Description
convertToPdfA(File input)	File	Converts a PDF file to PDF/A format for long-term archiving and returns a new temporary file with the result.

Utility

generateSample

Description:

Method	Return values	Description
generateSample(int paragraphs, OutputStream os)	void	Generates a sample Lorem Ipsum PDF with the specified number of paragraphs.

createPdfWithText

Description:

Method	Return values	Description
createPdfWithText(String text, File out)	void	Creates a simple single-page PDF containing the given text and writes it to the specified output file.

Example:

File out = FileUtils.createTempFile("pdf");
PDFUtils.createPdfWithText("Hello, OpenKM!", out);