failed to decode image from parse

Question

I am trying to decode the image that i am getting from parse while i send it to another functions for decryption, however i can't seem to get the file to decrypt correctly as on the decode line i get that the string was null therefore nothing to decode, How can i retrieve the parse file and decrypt then send it to decode.

My Parse function

case R.id.decryptButton:


    Intent i = getIntent();
    image = i.getStringExtra("image");
    progressDialog = ProgressDialog.show(SingleFileView.this, "",
    "Downloading Image...", true);

    // Locate the class table named "ImageUpload" in Parse.com
    ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(
                                                           "NewFiles");

    // Locate the objectId from the class
         query.getInBackground(objectId,
         new GetCallback<ParseObject>() {

         public void done(ParseObject object,
            ParseException e) {
            // TODO Auto-generated method stub

            // Locate the column named "ImageName" and set
            // the string

           final ParseFile fileObject = (ParseFile) object
               .get("ImageFile");
               fileObject
               .getDataInBackground(new GetDataCallback() {
                  public void done(byte[] data,
                     ParseException e) {
                        if (e == null) {
                          Log.d("test",
                            "We've got data in data.");
                            // Decode the Byte[] into
                            // Bitmap
                            FileInputStream fis = null;
                            saveFile(data, "temp.jpeg");

                            try {
                             File xx = new File(Environment.getExternalStorageDirectory()+"/temp.jpeg");
                             fis = new FileInputStream(String.valueOf(data));
                             System.out.print(fileObject.getUrl());
                             System.out.print(fis);

                             } catch (FileNotFoundException e1) {
                             e1.printStackTrace();
                             }
                             byte[] dmg = decrypt(key, fis);
                             Bitmap bmp = BitmapFactory
                            .decodeByteArray(
                            dmg, 0,
                            dmg.length);

                          // Get the ImageView from
                          // main.xml
                          ImageView image = (ImageView) findViewById(R.id.image);

                          // Set the Bitmap into the
                          // ImageView
                          image.setImageBitmap(bmp);

                         // Close progress dialog
                         progressDialog.dismiss();

                         } else {
                         Log.d("test",
                         "There was a problem downloading the data.");
                         }
                      }
                   });
         }
});

My Decrypt and Save File functions

private byte[] decrypt(byte[] skey, InputStream fis){

    SecretKeySpec skeySpec = new SecretKeySpec(skey, "AES");
    Cipher cipher;
    byte[] decryptedData=null;
    CipherInputStream cis=null;
    try {
        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, skeySpec, new IvParameterSpec(iv));
        // Create CipherInputStream to read and decrypt the image data
        cis = new CipherInputStream(fis, cipher);
        // Write encrypted image data to ByteArrayOutputStream
        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
        byte[] data = new byte[2048];
        while ((cis.read(data)) != -1) {
            buffer.write(data);
        }
        buffer.flush();
        decryptedData=buffer.toByteArray();

    }catch(Exception e){
        e.printStackTrace();
    }
    finally{
        try {
            fis.close();
            cis.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    return decryptedData;
}
public void saveFile(byte[] data, String outFileName){
    FileOutputStream fos=null;
    try {
        fos=new FileOutputStream(Environment.getExternalStorageDirectory()+File.separator+outFileName);
        fos.write(data);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    finally{
        try {
            fos.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

I don't seem to locate the issue with the file as i am unsure whether the problem is with the decryption method or the file i am getting from parse is done incorrectly.

Answer 1

The error is: "the string was null therefore nothing to decode" which says there is no input, that is what to look at. IOW, debug, breakpoints, single steeping in the debugger, print variables.