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Unable to create password protected existing PDF file

I am trying to make password protected PDF file which is already created in my directory .
Below is my sample code:
try {
PdfReader pdfReader = new PdfReader("D:/test/SI1491232250299.pdf");
PdfStamper pdfStamper = new PdfStamper(pdfReader, new FileOutputStream("D:/test/SI1491232250299.pdf"));
pdfStamper.setEncryption("abc".getBytes(), "abc".getBytes(), PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128);
pdfStamper.close();
} catch (Exception e) {
e.printStackTrace();
}
After execution got java.io.EOFException exception

My deflater class works incorecctly

My compression class works incorrectly. When i am trying to compress simple file that contains sentence "something", compressed and uncompressed returns something other. Here is my deflating code:
public static void inflate(String arg) throws Exception {
try {
FileInputStream fin = new FileInputStream(arg);
InflaterInputStream in = new InflaterInputStream(fin);
FileOutputStream fout = new FileOutputStream("def.txt");
int i;
while ((i = in.read()) != -1) {
fout.write((byte) i);
fout.flush();
}
fin.close();
fout.close();
in.close();
} catch (Exception e) {
System.out.println(e);
}
new File(arg).delete();
new File("def.txt").renameTo(new File(arg));
}
public static void deflate(String arg) throws Exception {
try {
FileInputStream fin = new FileInputStream(arg);
FileOutputStream fout = new FileOutputStream("def.txt");
DeflaterOutputStream out = new DeflaterOutputStream(fout);
int i;
while ((i = fin.read()) != -1) {
out.write((byte) i);
out.flush();
}
fin.close();
out.close();
} catch (Exception e) {
System.out.println(e);
}
new File(arg).delete();
new File("def.txt").renameTo(new File(arg));
}
I call it using
public static void main(String[] args) {
try {
Main.deflate(args[0]);
Main.inflate(args[0]);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
So how to fix my code? I think that problem is not in deflating code.

Your code does seem to work as expected.
Running it on a text file containing the word 'something' returns an identical file.
To confirm that the output is the same, try editing the following lines:
Test.inflate("def.txt");
which is in your main function and
FileOutputStream fout = new FileOutputStream("output.txt");
from your inflate function.
Then comment out the following lines in both your deflate() and inflate() functions
//new File(arg).delete();
//new File("def.txt").renameTo(new File(arg));
The program will now take an input file, I used input.txt with the word 'something' as per your example, and create a deflated file def.txt and an output.txt file that is created by inflating def.txt.
The output file should match the input file exactly, while the deflated file should be different. If not, there must be some further information about the program that is missing.

OutofMemory error while writing a large file Android

I'm trying to encrypt a large file which is 500MB but my code throws an out of memory error, for small files below 50MB the code works fine. Im using a third party library called JNCryptor for encryption, please have a look at my code and correct me if any mistake. Thanks in advance.
public void encrypt() {
String file = Environment.getExternalStorageDirectory() + "/sai/ravi_enc.exe";
byte[] filedata = null;
try {
filedata = IOUtils.toByteArray(new FileInputStream(file));
} catch (IOException e) {
e.printStackTrace();
}
JNCryptor cryptor = new AES256JNCryptor();
String password = "123456789";
try {
byte[] ciphertext = cryptor.decryptData(filedata, password.toCharArray());
String Outfile = Environment.getExternalStorageDirectory() + "/sai/ravi_dec.exe";
writeFile(ciphertext, Outfile);
System.out.println("Done");
} catch (CryptorException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void writeFile(byte[] data, String fileName) throws IOException {
FileOutputStream out = new FileOutputStream(fileName);
out.write(data);
out.close();
}

This is up to JNCryptor to well manage memory, especially if it uses temp buffer. It is better to work on streams instead of buffers. Just for testing, if you write directly the fileData to your outFile, do you get OutOfMemoryError?
writeFile(filedata, Outfile);

How to check if a PDF is Password Protected or not

I am trying to use iText's PdfReader to check if a given PDF file is password protected or not, but am getting this exception:
Exception in thread "Main Thread" java.lang.NoClassDefFoundError:org/bouncycastle/asn1/ASN1OctetString
But when testing the same code against a non-password protected file it runs fine. Here is the complete code:
try {
PdfReader pdf = new PdfReader("C:\\abc.pdf");
} catch (IOException e) {
e.printStackTrace();
}

In the old version of PDFBox
try
{
InputStream fis = new ByteArrayInputStream(pdfBytes);
PDDocument doc = PDDocument.load(fis);
if(doc.isEncrypted())
{
//Then the pdf file is encrypeted.
}
}
In the newer version of PDFBox (e.g. 2.0.4)
InputStream fis = new ByteArrayInputStream(pdfBytes);
boolean encrypted = false;
try {
PDDocument doc = PDDocument.load(fis);
if(doc.isEncrypted())
encrypted=true;
doc.close();
}
catch(InvalidPasswordException e) {
encrypted = true;
}
return encrypted;

Use Apache PDFBox - Java PDF Library from here:Sample Code:
try
{
document = PDDocument.load( "C:\\abc.pdf");
if(document.isEncrypted())
{
//Then the pdf file is encrypeted.
}
}

The way I do it is by attempting to read the PDF file using PdfReader without passing a password of course. If the file is password protected, a BadPasswordException will be thrown. This is using the iText library.

Here's a solution that doesn't require 3rd party libraries, using the PdfRenderer API.
fun checkIfPdfIsPasswordProtected(uri: Uri, contentResolver: ContentResolver): Boolean {
val parcelFileDescriptor = contentResolver.openFileDescriptor(uri, "r")
?: return false
return try {
PdfRenderer(parcelFileDescriptor)
false
} catch (securityException: SecurityException) {
true
}
}
Reference: https://developer.android.com/reference/android/graphics/pdf/PdfRenderer

try {
PdfReader pdfReader = new PdfReader(String.valueOf(file));
pdfReader.isEncrypted();
} catch (IOException e) {
e.printStackTrace();
}
Using iText PDF library you can check. If it went to an exception handle it(ask for password)

Try this code:
boolean isProtected = true;
PDDocument pdfDocument = null;
try
{
pdfDocument = PDDocument.load(new File("your file path"));
isProtected = false;
}
catch(Exception e){
LOG.error("Error while loading file : ",e);
}
Syste.out.println(isProtected);
If your document is password protected then it can not load document and throw IOException.
Verified above code using pdfbox-2.0.4.jar

public boolean checkPdfEncrypted(InputStream fis) throws IOException {
boolean encrypted = false;
try {
PDDocument doc = PDDocument.load(fis);
if (doc.isEncrypted())
encrypted = true;
doc.close();
} catch (
IOException e) {
encrypted = true;
}
return encrypted;
}
Note: There is one corner case in iText some file are encrypted protected but open without a password, to read those files and add water mark like this
PdfReader reader = new PdfReader(src);
reader.setUnethicalReading(true);

I didn't want to use any third party library, so i used this -
try {
new PdfRenderer(ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY));
} catch (Exception e) {
e.printStackTrace();
// file is password protected
}
If the file was password protected, i didn't use it.

Create a Word file using POI

My requirement is that I should read a template file and change some values in its content and write it back to another file. Most importantly it should have the same styles as that of the template.
The problem I face is that I am able to read and write, but its very difficult to transfer the styles as well. Especially I am tired trying to apply the paragraph styles to the document. Pls help me..... this is my code
public static void main(String[] args) {
try {
HWPFDocument templateFile = new HWPFDocument(new FileInputStream("D:\\POI\\testPOIin.doc"));
HWPFDocument blankFile = new HWPFDocument(new FileInputStream("D:\\POI\\blank.doc"));
ParagraphProperties pp = templateFile.getRange().getParagraph(4).cloneProperties();
blankFile.getRange().insertAfter(pp, 0);
OutputStream out = new FileOutputStream("D:\\POI\\testPOIout.doc");
blankFile.write(out);
} catch (FileNotFoundException fnfe) {
// TODO: Add catch code
fnfe.printStackTrace();
} catch (Exception ioe) {
// TODO: Add catch code
ioe.printStackTrace();
}
}
}
Pls let me know that I am doing wrong.....

I also had similar task and after investigation i created solution, but it works only for docx files:
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream(new File("transformed.docx"));
XWPFDocument doc = new XWPFDocument(new FileInputStream(new File("original.docx")));
for(XWPFParagraph p:doc.getParagraphs()){
for(XWPFRun r:p.getRuns()){
for(CTText ct:r.getCTR().getTList()){
String str = ct.getStringValue();
if(str.contains("NAME")){
str = str.replace("NAME", "Java Dev");
ct.setStringValue(str);
}
}
}
}
doc.write(fos);
}
it operates on low level elements so it saves styles and other props. Hope it will help somebody.