PDFCrypt.java

/**
 * This class allows users to encrypt or decrypt multiple PDF files through an
 * intuitive graphical interface (without using the PDFBox's command line).
 *
 * @author Eric Normandin
 */

import java.io.File;
import java.io.IOException;

import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.NoSuchFileException;

/*******************
 *     PDFbox      *
 *******************/
import org.apache.pdfbox.Loader;
//import org.apache.pdfbox.util.Version;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.encryption.InvalidPasswordException;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.pdmodel.encryption.StandardProtectionPolicy;


public class PDFCrypt {
	public int encryptPDF(
			String inputFilePath,
			String outputFilePath,
			char[] userPassword,
			char[] ownerPassword) throws IOException {
		try (PDDocument document = Loader.loadPDF(new File(inputFilePath))) {
			// Load the PDF file
			//PDDocument document = Loader.loadPDF(new File(inputFilePath));
			// Create a protection policy with AES 128-bit
			AccessPermission accessPermission = new AccessPermission();
			//StandardProtectionPolicy protectionPolicy = new StandardProtectionPolicy(
			//		String.copyValueOf(ownerPassword),
			//		String.copyValueOf(userPassword),
			//		accessPermission
			//);
			StandardProtectionPolicy protectionPolicy = new StandardProtectionPolicy(
					String.valueOf(ownerPassword),
					String.valueOf(userPassword),
					accessPermission
			);
			protectionPolicy.setEncryptionKeyLength(128); // AES 128-bit
			protectionPolicy.setPermissions(accessPermission);
			// Apply encryption to the document
			document.protect(protectionPolicy);
			// Delete the destination file if it already exists
			Files.deleteIfExists(Paths.get(outputFilePath));
			// Save the encrypted document
			document.save(outputFilePath);
			document.close(); // not necessary, the "try-with-resources" do it also.
			return 0;
		}
		catch (NoSuchFileException e) {
			//e.printStackTrace();
			return 1;
		}
		catch (IOException e) {
			//e.printStackTrace();
			return 1;
		}
		catch (Exception e) {
			//e.printStackTrace();
			return 1;
		}
	}
	
	public int decryptPDF(
			String inputFilePath,
			String outputFilePath,
			char[] password) throws IOException {
		//try (PDDocument document = Loader.loadPDF(new File(inputFilePath), String.copyValueOf(password))) {
		try (PDDocument document = Loader.loadPDF(new File(inputFilePath), String.valueOf(password))) {
			// Load the encrypted PDF document using  Loader.loadPDF
			//PDDocument document = Loader.loadPDF(new File(inputFilePath), password);
			// Remove document protection
			document.setAllSecurityToBeRemoved(true);
			// Delete the destination file if it already exists
			Files.deleteIfExists(Paths.get(outputFilePath));
			// Save the decrypted document
			document.save(outputFilePath);
			document.close(); // not necessary, the "try-with-resources" do it also.
			//Success
			return 0;
		}
		catch (InvalidPasswordException e) {
			//e.printStackTrace();
			return 1;
		}
		catch (NoSuchFileException e) {
			//e.printStackTrace();
			return 1;
		}
		catch (IOException e) {
			//e.printStackTrace();
			return 1;
		}
		catch (Exception e) {
			//e.printStackTrace();
			return 1;
		}
	}
}