Develop Reference

How to cache images to specific folder just like whatsapp

i am building a chat application using firebase. I am using Glide to display images
Glide.with(getApplicationContext())
.load(imageUrl)
.crossFade()
.fitCenter()
.placeholder(R.drawable.loading)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(imageView);
I want to save the images to a specific folder in Internal Storage just like whatsapp does and load images from there after it has been saved.Images are uploaded on Firebase Storage and its URL is saved in Firebase Database and i load them in a imageView with the url using Glide

private static final String IMAGE_DIRECTORY = "/yourfoldername/images";
//this method return your folder image path
public String saveImage(Bitmap myBitmap) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
myBitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
File wallpaperDirectory = new File(
Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY);
// have the object build the directory structure, if needed.
if (!wallpaperDirectory.exists()) {
wallpaperDirectory.mkdirs();
}
try {
File f = new File(wallpaperDirectory, Calendar.getInstance().getTimeInMillis() + ".jpg");
f.createNewFile();
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
MediaScannerConnection.scanFile(this,
new String[]{f.getPath()},
new String[]{"image/jpeg"}, null);
fo.close();
Log.d("TAG", "File Saved::--->" + f.getAbsolutePath());
return f.getAbsolutePath();
} catch (IOException e1) {
e1.printStackTrace();
}
return "";
}
// glide load image
Glide.with(this)
.load(imageUrl)
.asBitmap()
.into(new SimpleTarget<Bitmap>() {
#Override
public void onResourceReady(Bitmap resource, GlideAnimation glideAnimation) {
String imagepath = saveImage(resource);
// Parse the gallery image url to uri
Uri savedImageURI = Uri.parse(imagepath);
// Display the saved image to ImageView
iv_saved.setImageURI(savedImageURI);
}
});

How to save an image attached to the image view?

I am using a Glide library for loading remote URLs into ImageView's.
I want to save the image from this ImageView to gallery. (I don't want to make another network call again to download the same image).
How we can achieve this?

Glide.with(yourApplicationContext))
.load(youUrl)
.asBitmap()
.into(new SimpleTarget<Bitmap>(myWidth, myHeight) {
#Override
public void onResourceReady(Bitmap bitmap, GlideAnimation anim) {
//set bitmap to imageview and save
}
};

BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable();
Bitmap bitmap = drawable.getBitmap();
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap, 200, 200, false);
scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 60, byteArrayOutputStream);
String fileName = "image.jpeg";
File file = new File("your_directory_path/"
+ fileName);
try {
file.createNewFile();
// write the bytes in file
FileOutputStream fileOutputStream = new FileOutputStream(file);
fileOutputStream.write(byteArrayOutputStream.toByteArray());
// remember close the FileOutput stream
fileOutputStream.close();
ToastHelper.show(getString(R.string.qr_code_save));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
ToastHelper.show("Error");
}
Note : If your drawble is not always an instanceof BitmapDrawable
Bitmap bitmap;
if (mImageView.getDrawable() instanceof BitmapDrawable) {
bitmap = ((BitmapDrawable) mImageView.getDrawable()).getBitmap();
} else {
Drawable d = mImageView.getDrawable();
bitmap = Bitmap.createBitmap(d.getIntrinsicWidth(), d.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
}
Try this

I haven't try this way. But i think this match your problem. Put this code on onBindViewHolder of your RecyclerView adapter.
Glide.with(yourApplicationContext))
.load(youUrl)
.asBitmap()
.into(new SimpleTarget<Bitmap>(myWidth, myHeight) {
#Override
public void onResourceReady(Bitmap bitmap, GlideAnimation anim) {
//Set bitmap to your ImageView
imageView.setImageBitmap(bitmap);
viewHolder.saveButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
//Save bitmap to gallery
saveToGallery(bitmap);
}
});
}
};

This might help you
public void saveBitmap(ImageView imageView) {
Bitmap bitmap = ((GlideBitmapDrawable) imageView.getDrawable()).getBitmap();
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/My Images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-" + n + ".jpg";
File file = new File(myDir, fname);
if (file.exists()) file.delete();
try {
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
} catch (Exception ex) {
//ignore
}
}

How to take screen-shot of app screen in android?

I am developing an application in which I have to take screen-shot of app screen
right now I used below code it is not working. I am null bitmap image
Process sh = Runtime.getRuntime().exec("su", null,null);
OutputStream os = sh.getOutputStream();
os.write(("/system/bin/screencap -p " + "/sdcard/"+ "bs_score_img" +".png").getBytes("ASCII"));
os.flush();
os.close();
sh.waitFor();
String screenShot = Environment.getExternalStorageDirectory().toString()+"/bs_score_img.png";
Log.i("TAG:Score: screenShot path=", screenShot);
Bitmap bmp = BitmapFactory.decodeFile(new File(screenShot).getAbsolutePath());

try this :
Process sh = Runtime.getRuntime().exec("su", null,null);
OutputStream os = sh.getOutputStream();
os.write(("/system/bin/screencap -p " + "/sdcard/img.png").getBytes("ASCII"));
os.flush();
os.close();
sh.waitFor();
then read img.png as bitmap and convert it jpg as follows
Bitmap screen = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+
File.separator +"img.png");
//my code for saving
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
screen.compress(Bitmap.CompressFormat.JPEG, 15, bytes);
//you can create a new file name "test.jpg" in sdcard folder.
File f = new File(Environment.getExternalStorageDirectory()+ File.separator + "test.jpg");
f.createNewFile();
//write the bytes in file
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
// remember close de FileOutput
fo.close();
Google has a library with which you can take screenshot without rooting, I tried that, But i am sure that it will eat out the memory as soon as possible.
Try http://code.google.com/p/android-screenshot-library/
or try this :
View v1 = L1.getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bm = v1.getDrawingCache();
BitmapDrawable bitmapDrawable = new BitmapDrawable(bm);
image = (ImageView) findViewById(R.id.screenshots);
image.setBackgroundDrawable(bitmapDrawable);

I found this code from another post:
// image naming and path to include sd card appending name you choose for file
String mPath = Environment.getExternalStorageDirectory().toString() + "/" + ACCUWX.IMAGE_APPEND;
// create bitmap screen capture
Bitmap bitmap;
View v1 = mCurrentUrlMask.getRootView();
v1.setDrawingCacheEnabled(true);
bitmap = Bitmap.createBitmap(v1.getDrawingCache());
v1.setDrawingCacheEnabled(false);
OutputStream fout = null;
imageFile = new File(mPath);
try {
fout = new FileOutputStream(imageFile);
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fout);
fout.flush();
fout.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Let's say that you clicked on button
findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Bitmap bitmap = takeScreenshot();
saveBitmap(bitmap);
}
});
After that you need this two methods
public Bitmap takeScreenshot() {
View rootView = findViewById(android.R.id.content).getRootView();
rootView.setDrawingCacheEnabled(true);
return rootView.getDrawingCache();
}
public void saveBitmap(Bitmap bitmap) {
File imagePath = new File(Environment.getExternalStorageDirectory() + "/screenshot.png");
FileOutputStream fos;
try {
fos = new FileOutputStream(imagePath);
bitmap.compress(CompressFormat.JPEG, 100, fos);
fos.flush();
fos.close();
} catch (FileNotFoundException e) {
Log.e("GREC", e.getMessage(), e);
} catch (IOException e) {
Log.e("GREC", e.getMessage(), e);
}
}

public Bitmap screenShot(View view) {
Bitmap bitmap = Bitmap.createBitmap(view.getWidth(),
view.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
view.draw(canvas);
return bitmap;
}
just call this method with the view you want a snapshot of.. so if you want the whole screen just pass in you top most ViewGroup. if you want the System controls also just call:

you can try this
private Bitmap getScreen(){
mDecorView = getWindow().getDecorView();
runOnUiThread(new Runnable() {
public void run() {
mDecorView.invalidate();
mDecorView.post(this);
}
});
View v1 = mDecorView.getRootView();
System.out.println("Root View : "+v1);
v1.setDrawingCacheEnabled(true);
return v1.getDrawingCache();
}
here mDecorView is View .

Here how you can capture screen and save it in your storage
give permissions for creating file in external storage
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
And this is code for activity.
private void takeScreenshot() {
Date now = new Date();
android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);
try {
// image naming and path to include sd card appending name you choose for file
String mPath = Environment.getExternalStorageDirectory().toString() + "/" + now + ".jpg";
// create bitmap screen capture
View v1 = getWindow().getDecorView().getRootView();
v1.setDrawingCacheEnabled(true);
Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
v1.setDrawingCacheEnabled(false);
File imageFile = new File(mPath);
FileOutputStream outputStream = new FileOutputStream(imageFile);
int quality = 100;
bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream);
outputStream.flush();
outputStream.close();
openScreenshot(imageFile);
} catch (Throwable e) {
// Several error may come out with file handling or OOM
e.printStackTrace();
}
}
This is how you can capture the screen.

Reading an image file into bitmap from sdcard, why am I getting a NullPointerException?

How can I read an image file into bitmap from sdcard?
_path = Environment.getExternalStorageDirectory().getAbsolutePath();
System.out.println("pathhhhhhhhhhhhhhhhhhhh1111111112222222 " + _path);
_path= _path + "/" + "flower2.jpg";
System.out.println("pathhhhhhhhhhhhhhhhhhhh111111111 " + _path);
Bitmap bitmap = BitmapFactory.decodeFile(_path, options );
I am getting a NullPointerException for bitmap. It means that the bitmap is null. But I have an image ".jpg" file stored in sdcard as "flower2.jpg". What's the problem?

The MediaStore API is probably throwing away the alpha channel (i.e. decoding to RGB565). If you have a file path, just use BitmapFactory directly, but tell it to use a format that preserves alpha:
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(photoPath, options);
selected_photo.setImageBitmap(bitmap);
or
http://mihaifonoage.blogspot.com/2009/09/displaying-images-from-sd-card-in.html

It works:
Bitmap bitmap = BitmapFactory.decodeFile(filePath);

Try this code:
Bitmap bitmap = null;
File f = new File(_path);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
try {
bitmap = BitmapFactory.decodeStream(new FileInputStream(f), null, options);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
image.setImageBitmap(bitmap);

I wrote the following code to convert an image from sdcard to a Base64 encoded string to send as a JSON object.And it works great:
String filepath = "/sdcard/temp.png";
File imagefile = new File(filepath);
FileInputStream fis = null;
try {
fis = new FileInputStream(imagefile);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
Bitmap bm = BitmapFactory.decodeStream(fis);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 100 , baos);
byte[] b = baos.toByteArray();
encImage = Base64.encodeToString(b, Base64.DEFAULT);

Convert Bitmap to File

I understand that using BitmapFactory can convert a File to a Bitmap, but is there any way to convert a Bitmap image to a File?

Hope it will help u:
//create a file to write bitmap data
File f = new File(context.getCacheDir(), filename);
f.createNewFile();
//Convert bitmap to byte array
Bitmap bitmap = your bitmap;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(CompressFormat.PNG, 0 /*ignored for PNG*/, bos);
byte[] bitmapdata = bos.toByteArray();
//write the bytes in file
FileOutputStream fos = new FileOutputStream(f);
fos.write(bitmapdata);
fos.flush();
fos.close();

Try this:
bitmap.compress(Bitmap.CompressFormat.PNG, quality, outStream);
See this

File file = new File("path");
OutputStream os = new BufferedOutputStream(new FileOutputStream(file));
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
os.close();

Converting Bitmap to File needs to be done in background (NOT IN THE MAIN THREAD) it hangs the UI specially if the bitmap was large
File file;
public class fileFromBitmap extends AsyncTask<Void, Integer, String> {
Context context;
Bitmap bitmap;
String path_external = Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg";
public fileFromBitmap(Bitmap bitmap, Context context) {
this.bitmap = bitmap;
this.context= context;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
// before executing doInBackground
// update your UI
// exp; make progressbar visible
}
#Override
protected String doInBackground(Void... params) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
file = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");
try {
FileOutputStream fo = new FileOutputStream(file);
fo.write(bytes.toByteArray());
fo.flush();
fo.close();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
// back to main thread after finishing doInBackground
// update your UI or take action after
// exp; make progressbar gone
sendFile(file);
}
}
Calling it
new fileFromBitmap(my_bitmap, getApplicationContext()).execute();
you MUST use the file in onPostExecute .
To change directory of file to be stored in cache
replace line :
file = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");
with :
file = new File(context.getCacheDir(), "temporary_file.jpg");

Most of the answers are too lengthy or too short not fulfilling the purpose. For those how are looking for Java or Kotlin code to Convert bitmap to File Object. Here is the detailed article I have written on the topic. Convert Bitmap to File in Android
public static File bitmapToFile(Context context,Bitmap bitmap, String fileNameToSave) { // File name like "image.png"
//create a file to write bitmap data
File file = null;
try {
file = new File(Environment.getExternalStorageDirectory() + File.separator + fileNameToSave);
file.createNewFile();
//Convert bitmap to byte array
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 0 , bos); // YOU can also save it in JPEG
byte[] bitmapdata = bos.toByteArray();
//write the bytes in file
FileOutputStream fos = new FileOutputStream(file);
fos.write(bitmapdata);
fos.flush();
fos.close();
return file;
}catch (Exception e){
e.printStackTrace();
return file; // it will return null
}
}

Hope this helps u
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Get the bitmap from assets and display into image view
val bitmap = assetsToBitmap("tulip.jpg")
// If bitmap is not null
bitmap?.let {
image_view_bitmap.setImageBitmap(bitmap)
}
// Click listener for button widget
button.setOnClickListener{
if(bitmap!=null){
// Save the bitmap to a file and display it into image view
val uri = bitmapToFile(bitmap)
image_view_file.setImageURI(uri)
// Display the saved bitmap's uri in text view
text_view.text = uri.toString()
// Show a toast message
toast("Bitmap saved in a file.")
}else{
toast("bitmap not found.")
}
}
}
// Method to get a bitmap from assets
private fun assetsToBitmap(fileName:String):Bitmap?{
return try{
val stream = assets.open(fileName)
BitmapFactory.decodeStream(stream)
}catch (e:IOException){
e.printStackTrace()
null
}
}
// Method to save an bitmap to a file
private fun bitmapToFile(bitmap:Bitmap): Uri {
// Get the context wrapper
val wrapper = ContextWrapper(applicationContext)
// Initialize a new file instance to save bitmap object
var file = wrapper.getDir("Images",Context.MODE_PRIVATE)
file = File(file,"${UUID.randomUUID()}.jpg")
try{
// Compress the bitmap and save in jpg format
val stream:OutputStream = FileOutputStream(file)
bitmap.compress(Bitmap.CompressFormat.JPEG,100,stream)
stream.flush()
stream.close()
}catch (e:IOException){
e.printStackTrace()
}
// Return the saved bitmap uri
return Uri.parse(file.absolutePath)
}
}