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How to create File from list of byte arrays in Android?

I am trying to transfer a .mp4 file using WebRTC and it's DataChannel. In order to do that I am breaking the file into chunks like below:
FileInputStream is = new FileInputStream(file);
byte[] chunk = new byte[260000];
int chunkLen = 0;
sentFileByte = new ArrayList<>();
while ((chunkLen = is.read(chunk)) != -1) {
sentFileByte.add(chunk);
}
After that, sending the chunks by index like:
byte[] b = sentFileByte.get(index);
ByteBuffer bb = ByteBuffer.wrap(b);
bb.put(b);
bb.flip();
dataChannel.send(new DataChannel.Buffer(bb, true));
On the receiver end I am receiving the chunks and adding it to an Arraylist
receivedFileByteArr.add(chunkByteArr);
After receiving all the chunks successfully I am trying to convert these in to a file like below:
String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath() + "/" + fileName;
File file = new File(path);
try {
FileOutputStream fileOutputStream = new FileOutputStream(file);
for (int i = 0; i < receivedFileByteArr.size(); i++) {
fileOutputStream.write(receivedFileByteArr.get(i));
}
fileOutputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
After completing all these steps, file is created successfully. File size is also same. But problem is the file is not playable in any video player. I guess I am making some mistake on FileInputStream and FileOutputStream. I need help to fix this error.

convert PDF file to byte array in android

i want convert PDF file to byte array in (onActivityResult)
I tried several different ways but it didn't work
Please answer if anyone knows.
Update :
case 1212 :
if (resultCode == RESULT_OK){
Uri uri = data.getData();
File file = new File(uri.getPath());
int size = (int) file.length();
byte[] bytes = new byte[size];
try {
BufferedInputStream buf = new BufferedInputStream(new FileInputStream(file));
buf.read(bytes, 0, bytes.length);
buf.close();
} catch (FileNotFoundException e) {
Toast.makeText(getApplicationContext(),"FileNotFound",Toast.LENGTH_LONG).show();
e.printStackTrace();
} catch (IOException e) {
Toast.makeText(getApplicationContext(),"IOException",Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}else Toast.makeText(getApplicationContext(),"خطا!",Toast.LENGTH_LONG).show();
this code show FileNotFound Toast

Use Package java.nio.file from java 7
Path pdfFilePath = Paths.get("/file/path/your_file.pdf"); //File path
byte[] pdfByteArray = Files.readAllBytes(pdfFilePath );

When Decrypting Image, gives javax.crypto.BadPaddingException: pad block corrupted Android

Hi i'm new to android and Image encryption.
My scenario is like this,
first I'm encrypting the image file.
Then I'm uploading it to the Server
From my app I'm downloading encrypted image and saving it in SD card.
then I'm decrypting it before set it to the imageView
(See bottom for all need methods I have used..)
But I'm getting javax.crypto.BadPaddingException: pad block corrupted when decrypting. I read some articles about this exception but all are about text encryption. Can you help me to avoid this. Thank you in advance
Image Encrption using ...
private byte[] encrypt(byte[] raw, byte[] clear) throws Exception
{
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
Here I'm saving several other images as well, all saved in sd card successfully...
for (int i = 0; i < imageUrls.size(); i++)
{
File file = new File(imageUrls.get(i));
String metapath = CommonUtils.getDataFromPreferences("metaPath", "");
Log.d("metapath", metapath);
String extStorageDirectory = metapath + file.getName();
File wallpaperDirectory = new File(extStorageDirectory);
if (!wallpaperDirectory.exists() || wallpaperDirectory.length() == 0)
{
new DownloadImagesTask()
.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, imageUrls.get(i));
}
}
Toast toast = Toast.makeText(ScratchDetailsActivity.this, "Lottery was purchased and saved to sdcard/E-Lottery",
Toast.LENGTH_LONG);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
Image decryption...
decrypt the file here first argument is key and second is encrypted file which we get from SD card.
decrpt = simpleCrypto.decrypt(KEY, getImageFileFromSdCard());
bmpimg2 = BitmapFactory.decodeByteArray(decrpt, 0, decrpt.length);
Drawable d = new BitmapDrawable(getResources(), bmpimg2);
hiddenImage.setImageDrawable(d);
DownloadImageTask..
public class DownloadImagesTask extends AsyncTask<String, Void, InputStream>{
private String fileName;
#Override
protected InputStream doInBackground(String... urls)
{
//Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
return download_Image(urls[0]);
}
#Override
protected void onPostExecute(InputStream result)
{
storeImage(result);
}
private InputStream download_Image(String url)
{
InputStream is = null;
File file = new File(url);
fileName = file.getName();
try
{
URL aURL = new URL(url);
URLConnection conn = aURL.openConnection();
conn.connect();
is = conn.getInputStream();
}
catch (OutOfMemoryError e)
{
Log.e("Hub", "Error getting the image from server : " + e.getMessage().toString());
}
catch (IOException e)
{
Log.e("Hub", "Error getting the image from server : " + e.getMessage().toString());
}
return is;
}
public void storeImage(InputStream is)
{
String extStorageDirectory = CommonUtils.getDataFromPreferences("metaPath", "");
Log.d("extStorageDirectory", extStorageDirectory);
OutputStream outStream = null;
File wallpaperDirectory = new File(extStorageDirectory);
if (!wallpaperDirectory.exists())
{
wallpaperDirectory.mkdirs();
}
File outputFile = new File(wallpaperDirectory, fileName);
if (!outputFile.exists() || outputFile.length() == 0)
{
try
{
outStream = new FileOutputStream(outputFile);
}
catch (FileNotFoundException e1)
{
e1.printStackTrace();
}
try
{
int bytesRead = -1;
byte[] buffer = new byte[4096];
while ((bytesRead = is.read(buffer)) != -1)
{
outStream.write(buffer, 0, bytesRead);
}
outStream.close();
is.close();
Log.d("ScratchActivtiy", "Image Saved");
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}}
getImageFileFromSDCard method
/**
* This method fetch encrypted file which is save in sd card and convert it in byte array after that this file will
* be decrept.
*
* #return byte array of encrypted data for decription.
* #throws FileNotFoundException
*/
public byte[] getImageFileFromSdCard() throws FileNotFoundException
{
byte[] inarry = null;
try
{
String metapath = CommonUtils.getDataFromPreferences("metaPath", "");
File imageFolder = new File(metapath);
File urlFile = new File(selectedLottery.getImage());
for (File f : imageFolder.listFiles())
{
if (urlFile.getName().equals(f.getName()))
metapath = metapath + f.getName();
}
File imageFile = new File(metapath);
//Convert file into array of bytes.
FileInputStream fileInputStream = null;
byte[] bFile = new byte[(int) imageFile.length()];
fileInputStream = new FileInputStream(imageFile);
fileInputStream.read(bFile);
fileInputStream.close();
inarry = bFile;
}
catch (IOException e)
{
Log.d("Exception", e.getMessage());
}
return inarry;
}

There are a lot of things that might cause a Bad Padding exception. Obvious things to check are that for both encryption and decryption you are using:
the same key, that is byte-for-byte the same.
the same encryption mode (CBC, CTR or GCM usually).
the same IV/Nonce, again byte-for-byte the same.
the same padding (PKCS5 or PKCS7 are common).
Do not rely on system defaults, especially when encrypting on one system and decrypting on another, as you seem to be doing. If the system defaults are different, then your decryption will fail. Always explicitly set key, mode, IV and padding. There will be documented ways to do so in any reasonable crypto library.
If that doesn't solve it then you will need to do a bit more digging. Set the decryption method temporarily to NoPadding or whatever equivalent your library uses. That will let the decryption method ignore padding errors, and give you some output. Have a look at the output and compare it to the original input; you may have to look at hex dumps here to be sure what is happening.
Among the possibilities are:
the output is complete garbage: your key is wrong, or the IV/Nonce
is wrong for a stream cypher or GCM mode or CTR mode.
the first block is garbage with the rest matching the plaintext: you
have the wrong IV in CBC mode.
the output matches with some extra stuff at the end: the extra stuff
is padding. Set your decryption method to expect that type of
padding.
If none of these happen, then ask again here, describing the symptoms.
When you have got a solution, you must set your decryption method back to expect the correct padding. Leaving it set to NoPadding is not secure since any old garbage can be added to the decrypted plaintext.

Convert base64 string to Image in Java

I have an image being sent to me through a JSON string. I want to convert that string into an image in my android app and then display that image.
The JSON string looks like this:
"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAVI..."
Note: I truncated the string with a ...
I've got a function that (I think) converts the string into an image. Am I doing this right?
public Bitmap ConvertToImage(String image){
try{
InputStream stream = new ByteArrayInputStream(image.getBytes());
Bitmap bitmap = BitmapFactory.decodeStream(stream);
return bitmap;
}
catch (Exception e) {
return null;
}
}
Then I try to display it on my android activity like this
String image = jsonObject.getString("barcode_img");
Bitmap myBitmap = this.ConvertToImage(image);
ImageView cimg = (ImageView)findViewById(R.id.imageView1);
//Now try setting dynamic image
cimg.setImageBitmap(myBitmap);
However, when I do this, nothing shows up. I don't get any errors in the logcat. What am I doing wrong?
Thanks

I'm worried about that you need to decode only the base64 string to get the image bytes, so in your
"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAVI..."
string, you must get the data after data:image\/png;base64,, so you get only the image bytes and then decode them:
String imageDataBytes = completeImageData.substring(completeImageData.indexOf(",")+1);
InputStream stream = new ByteArrayInputStream(Base64.decode(imageDataBytes.getBytes(), Base64.DEFAULT));
This is a code so you understand how it works, but if you receive a JSON object it should be done the correct way:
Converting the JSON string to a JSON object.
Extract the String under data key.
Make sure that starts with image/png so you know is a png image.
Make sure that contains base64 string, so you know that data must be decoded.
Decode the data after base64 string to get the image.

InputStream stream = new ByteArrayInputStream(image.getBytes());
should be changed to
InputStream stream = new ByteArrayInputStream(Base64.decode(image.getBytes(), Base64.DEFAULT));
Refer http://developer.android.com/reference/android/util/Base64.html for details on how to do Base64 decoding.
Disclaimer: I have not checked for syntax, but this is how you should do it.

Here is the working code that converts the Base64 encoded inputStream and writes it to the disk.
I spent a few time to make it work correctly. So I hope this helps other developers.
public boolean writeImageToDisk(FileItem item, File imageFile) {
// clear error message
errorMessage = null;
FileOutputStream out = null;
boolean ret = false;
try {
// write thumbnail to output folder
out = createOutputStream(imageFile);
// Copy input stream to output stream
byte[] headerBytes = new byte[22];
InputStream imageStream = item.getInputStream();
imageStream.read(headerBytes);
String header = new String(headerBytes);
// System.out.println(header);
byte[] b = new byte[4 * 1024];
byte[] decoded;
int read = 0;
while ((read = imageStream.read(b)) != -1) {
// System.out.println();
if (Base64.isArrayByteBase64(b)) {
decoded = Base64.decodeBase64(b);
out.write(decoded);
}
}
ret = true;
} catch (IOException e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
errorMessage = "error: " + sw;
} finally {
if (out != null) {
try {
out.close();
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
System.out.println("Cannot close outputStream after writing file to disk!" + sw.toString());
}
}
}
return ret;
}
/**
* Helper method for the creation of a file output stream.
*
* #param imageFolder
* : folder where images are to be saved.
* #param id
* : id of spcefic image file.
* #return FileOutputStream object prepared to store images.
* #throws FileNotFoundException
*/
protected FileOutputStream createOutputStream(File imageFile) throws FileNotFoundException {
imageFile.getParentFile().mkdirs();
return new FileOutputStream(imageFile);
}

How to unzip a 7zip archive in Android?

I have a 7zip archive which contains some hundred files separated into different directories. The target is to download it from a FTP server and then extract it on the phone.
My problem is that the 7zip SDK doesn't contain a lot. I am looking for examples, tutorials and snippets regarding the decompression of 7z files.
(Decompression via Intent is only a secondary option)

Go here:
LZMA SDK just provides the encoder and decoder for encoding/decoding the raw data, but 7z archive is a complex format for storing multiple files.

i found this page that provides an alternative that works like a charm. You only have to add compile 'org.apache.commons:commons-compress:1.8'
to your build gradle script and use the feature you desire. For this issue i did the following :
AssetManager am = getAssets();
InputStream inputStream = null;
try {
inputStream = am.open("a7ZipedFile.7z");
File file1 = createFileFromInputStream(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
SevenZFile sevenZFile = null;
try{
File f = new File(this.getFilesDir(), "a7ZipedFile.7z");
OutputStream outputStream = new FileOutputStream(f);
byte buffer[] = new byte[1024];
int length = 0;
while((length=inputStream.read(buffer)) > 0) {
outputStream.write(buffer,0,length);
}
try {
sevenZFile = new SevenZFile(f);
SevenZArchiveEntry entry = sevenZFile.getNextEntry();
while (entry != null) {
System.out.println(entry.getName());
FileOutputStream out = openFileOutput(entry.getName(), Context.MODE_PRIVATE);
byte[] content = new byte[(int) entry.getSize()];
sevenZFile.read(content, 0, content.length);
out.write(content);
out.close();
entry = sevenZFile.getNextEntry();
}
sevenZFile.close();
outputStream.close();
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}catch (IOException e) {
//Logging exception
e.printStackTrace();
}
The only draw back is approximately 200k for the imported library. Other than that it is really easy to use.