How to save image file in android? - android

I am reading a image file into a byte array.This byte array i have to save again as a image file onto the sdcard.To read the file i have used the following code:
public void readimage()
{
InputStream ins_image = getResources().openRawResource(R.drawable.btn_cancel);
outputStream=new ByteArrayOutputStream();
try
{
ins_image.available();
} catch (IOException e) { e.printStackTrace(); }
try
{
Log.e( "Size of image", ""+ins_image.available());
} catch (IOException e) {e.printStackTrace();}
int size = 0;
byte[] buffer_image = new byte[200000];
try {
while((size=ins_image.read(buffer_image,0,200000))>=0)
{
outputStream.write(buffer_image,0,size);
}
} catch (IOException e) { e.printStackTrace(); }
int length_of_image= outputStream.toByteArray().length;
byte_image=outputStream.toByteArray();
Log.e("Size of image",""+length_of_image);
}
And the below code to save the file:
public void saveimage_fromarray()
{
File photo=new File(Environment.getExternalStorageDirectory(), "photo.png");
if (photo.exists())
{
photo.delete();
}
try
{
FileOutputStream fos=new FileOutputStream(photo.getPath());
fos.write(byte_image[0]);
fos.close();
}
catch (java.io.IOException e)
}
However the file is being saved but it does not display anything.Can somebody please tell me why is it so?

Set the size of the image you are getting in place of 0.
fos.write(byte_image[0]);

Seems like you're writing only one byte of the image.
fos.write(byte_image[0]);
Please compare source file, byte buffer, array and output file sizes.

why don't you simplify everything and just calls this method:
bmp.compress(Bitmap.CompressFormat.PNG, 100, <pass here a valid file outputstream>);

Related

(android) how to overwrite image on DCIM folder?

I already have a resized bitmap object.
with this bitmap, how can i overwrite this bitmap in DCIM folder??
I know that I should change the bitmap into File object...
please help me
(Assume that i also have the absolute path)
I tried this with the code below.
It creates a new file only if a file with same name doesn't exist.
Otherwise, it doesn't create a new file.
private void SaveBitmapToFileCache(Bitmap bitmap, String strFilePath) {
File fileCacheItem = new File(strFilePath);
OutputStream out = null;
try
{
fileCacheItem.createNewFile();
out = new FileOutputStream(fileCacheItem);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
try
{
out.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
Try something like this:
//File file= new File("FilePath"+ "/myfolder/myimage.jpg");
if(fileCacheItem .exists())
{
file.delete();
}

Write file from bytearray in same format that was before conversion

I have a file that was saved in database as a bytearray. I want to write the byte array to file at the same format that was before conversion into bytearray. For example if the file was docx i want to write as docx.
try
{
x = "/sdcard";
x+= "/temp.pdf";
FileOutputStream stream = new FileOutputStream(x);
try
{
stream.write(array);
stream.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
catch (FileNotFoundException e1)
{
e1.printStackTrace();
x="";
}

Reading Image from internal memory android gives null pointer exception

I am quite new to android. I want to save image to internal memory and later retrieve the image from internal memory and load it to image view. I have successfully stored the image in internal memory using the following code :
void saveImage() {
String fileName="image.jpg";
//File file=new File(fileName);
try
{
FileOutputStream fOut=openFileOutput(fileName, MODE_PRIVATE);
bmImg.compress(Bitmap.CompressFormat.JPEG, 100, fOut);
}
catch (Exception e)
{
e.printStackTrace();
}
}
using this code image is saved. But when i try to retrieve the image it gives me error. The code used to retrieve the image is :
FileInputStream fin = null;
ImageView img=new ImageView(this);
try {
fin = openFileInput("image.jpg");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
byte[] bytes = null;
try {
fin.read(bytes);
} catch (Exception e) {
e.printStackTrace();
}
Bitmap bmp=BitmapFactory.decodeByteArray(bytes,0,bytes.length);
img.setImageBitmap(bmp);
But i get a Null pointer exception.
I checked the file is there in internal memory at path :
/data/data/com.test/files/image.jpg
What am i doing wrong please help me out with this. I have gone through a lot of stack questions.
it is because your bytes array is null, instantiate it, and assign size.
byte[] bytes = null; // you should initialize it with some bytes size like new byte[100]
try {
fin.read(bytes);
} catch (Exception e) {
e.printStackTrace();
}
Edit 1: I am not sure but you can do something like
byte[] bytes = new byte[fin.available()]
Edit 2 : here is a better solution, as you are reading Image,
FileInputStream fin = null;
ImageView img=new ImageView(this);
try {
fin = openFileInput("image.jpg");
if(fin !=null && fin.available() > 0) {
Bitmap bmp=BitmapFactory.decodeStream(fin)
img.setImageBitmap(bmp);
} else {
//input stream has not much data to convert into Bitmap
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Helped by - Jason Robinson

How to receive byte array from Bluetooth and save byte array to SD card as an image file

I am working on an Android Application which needs to implement the Bluetooth functionality. It needs to receive an image from an external h/w device, and then save that byte array to SD card as an image file.
Here is my code:
public void run(){
Log.i(TAG, "BEGIN mConnectedThread");
byte[] buffer = new byte[4096];
//CREATE IMAGE FILE
File test=new File(Environment.getExternalStorageDirectory(), "test.jpg");
if (test.exists()) {
test.delete();
}
try {
fos = new FileOutputStream(test.getPath());
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Keep listening to the InputStream while connected
while (true) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
/*mEmulatorView.write(buffer, bytes);
// Send the obtained bytes to the UI Activity
mHandler.obtainMessage(BlueTerm.MESSAGE_READ, bytes, -1, buffer).sendToTarget();*/
//receivedData = new String(buffer);
receivedData=new String(buffer)
//WRITE BYTES TO FILE
try {
fos.write(buffer);
}
catch (java.io.IOException e) {
Log.e("PictureDemo", "Exception in photoCallback", e);
}
/*
Bitmap bitmap = null;
try {
bitmap = BitmapFactory.decodeByteArray(buffer , 0, buffer.length);
} catch (OutOfMemoryError e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
if(bitmap != null)
testModeOnScreen.saveBitmapToSdcardAndEmail(bytes, bitmap);
*/}
} catch (IOException e) {
Log.e(TAG, "disconnected", e);
connectionLost();
break;
}
}
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
My problem is that I am not getting any exception or crashes, but I am getting a corrupted image file.
There seem to be multiple issues here. For starters, garbage at the buffer tail, "Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected":
http://docs.oracle.com/javase/6/docs/api/java/io/InputStream.html#read()
Also, you may happen to need to use the bitmap functionality from Android.
Look how they exchange bitmaps here:
http://kamrana.wordpress.com/2012/05/12/sending-images-over-bluetooth-in-android/
And how they save to a file:
Save bitmap to file function
http://developer.android.com/reference/android/graphics/Bitmap.html#compress(android.graphics.Bitmap.CompressFormat, int, java.io.OutputStream)
You could find it easier hacking together those building blocks than reinventing them.
check this solution;)
String TAG="IMG";
File path = Environment.getExternalStoragePublicDirectory(("/mnt/exSdCard/RecievedIMAGE"));
File file = new File(path, "test.jpg");
BufferedInputStream bufferedInputStream = null;
try {
// Make sure that this path existe if it is not so create it
path.mkdirs();
bufferedInputStream = new BufferedInputStream(inputStream);
OutputStream os = new FileOutputStream(file);
final byte[] buffer = new byte[2048];
int available = 0;
while ((available = bufferedInputStream.read(buffer)) >= 0) {
os.write(buffer, 0, available);
}
bufferedInputStream.read(buffer);
bufferedInputStream.close();
os.close();
Log.d(TAG, "success" + buffer);
} catch (IOException e) {
// Unable to create file, likely because external storage is
// not currently mounted.
Log.w("ExternalStorage", "Error writing " + file, e);
}

saving file on sd card, writes file size 0

I have trouble with saving images on sd card. I can see the file on the sd card but file is empty (size 0). I tried saving it on the phone memory and it works fine. Here is my code.
Imagewritter {
public static boolean writeAsJPG(Context context, Bitmap bitmap,
String filename) {
filename = filename + ".jpg";
File path = Environment.getExternalStorageDirectory();
File f = new File(path, filename);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(f);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
fos = context.openFileOutput(filename, Context.MODE_WORLD_READABLE);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.d(TAG, "file not found");
return false;
}
bitmap.compress(CompressFormat.JPEG, quality, fos);
try {
fos.flush();
fos.close();
} catch (IOException e) {
Log.d(TAG, "error closing");
e.printStackTrace();
}
}
here is the code where the bitmap comes from.
DrawingView = (drawing) findViewById(R.id.drawing_view);
drawingBitmap = (Bitmap) DrawingView.getBitmap();
String idName = timeStampText;
//save Image as JPG
ImageWritter.writeAsJPG(getApplicationContext(), drawingBitmap, idName);
i think u have to add these permission in manifest file
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Get the image in byte array & check the size of that byte array.. I think you getting 0 size byte array.....
The only problem here is that I have two lines for writing the file. Using FileOutputStream and OpenFileOutput. Just remove these lines and it'll be fine.
try {
fos = context.openFileOutput(filename, Context.MODE_WORLD_READABLE);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.d(TAG, "file not found");
return false;
}

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