Question

I tried this code to encrypt my PDF so users cannot copy content from the PDF (just for testing, I know there’s something as OCR’ing :p)

import java.io.FileOutputStream;

import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;
import com.itextpdf.text.pdf.PdfWriter;

public class EncryptPDF {

private static final String INPUT_FILENAME = "/tmp/test.pdf";
private static final String OUTPUT_FILENAME = "/tmp/test_encrypted.pdf";
private static final String USER_PASSWORD = "";
private static final String OWNER_PASSWORD = "foobar";

public static void main(String[] args) {
    PdfReader reader = null;
    FileOutputStream out = null;
    PdfStamper stamper = null;

    try {
        // Define input
        reader = new PdfReader(INPUT_FILENAME);

        // Define output
        out = new FileOutputStream(OUTPUT_FILENAME);

        // Encrypt document
        stamper = new PdfStamper(reader, out);
        stamper.setEncryption(USER_PASSWORD.getBytes(), OWNER_PASSWORD.getBytes(), ~(PdfWriter.ALLOW_COPY | PdfWriter.ALLOW_PRINTING), PdfWriter.STANDARD_ENCRYPTION_128);
    } catch (Exception ex) {
        ex.printStackTrace();
    } finally {
        if (reader != null) {
            try {
                reader.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
        if (stamper != null) {
            try {
                stamper.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
        if (out != null) {
            try {
                out.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    }

}
}

… But when I open the PDF, I can still select content from it. I’m using iText 5.0.2.

Any idea’s on what I’m doing wrong?

Answer 1

As mentioned in my comment to the question, running the example code as is results in a NullPointerException during stamper.close() — which is quite natural as you first close the PdfReader and afterwards the PdfStamper, but the latter close() method accesses the PdfReader (already closed now) for its work.

When I run your code with the order of closing the PdfReader and the PdfWriter reversed, though, I get a proper result file with the access rights as required:

PS: I’m using iText version 5.3.5; if reversing the order of the close() calls does not help in your case, you may want to update from your version 5.0.2.