Develop Reference

Android: load images with zoom from URL

I am using to load my images with high resolution and zoom quality with the tutorial: https://github.com/davemorrissey/subsampling-scale-image-view
It uses images from Assets. How I could do to load images from a URL?

The class SubsamplingScaleImageView has also a method to load an image that isn't from Assets:
SubsamplingScaleImageView.setImageFile(String extFile)
So you can get the image from the URL and save it on internal storage. Then you can load the image using the path from internal storage.
To get the image as a Bitmap from an URL:
URL myFileUrl = new URL (StringURL);
HttpURLConnection conn = (HttpURLConnection) myFileUrl.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
Bitmap bm = BitmapFactory.decodeStream(is);
To save the Bitmap on internal storage:
FileOutputStream out = new FileOutputStream(context.getCacheDir() + filename);
bm.compress(Bitmap.CompressFormat.PNG, 90, out);
// Don't forget to add a finally clause to close the stream
Finally
SubsamplingScaleImageView imageView = (SubsamplingScaleImageView)findViewById(R.id.imageView);
imageView.setImageFile(context.getCacheDir() + filename);

I actually solved this by creating a Bitmap from the provided URL string extra, although I think this may defeat the purpose of SubsamplingScaleImageView because I'm loading the entire Bitmap.
private void locateImageView() throws URISyntaxException, IOException {
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
if (bundle.getString("imageUrl") != null) {
String imageUrl = bundle.getString("imageUrl");
Log.w(getClass().toString(), imageUrl);
imageView = (SubsamplingScaleImageView) findViewById(R.id.image);
URL newUrl = new URL(imageUrl);
try {
URL url = new URL(imageUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
imageView.setImage(ImageSource.bitmap(myBitmap));
} catch (IOException e) {
// Log exception
Log.w(getClass().toString(), e);
}
}
}
}

How to set android imageview from downloaded png

I have a database online that gives image file locations and file names
I am trying to update an imageview in an android screen. Here is my code that gets the image and the things I have tried:
// successfully received product details
JSONArray productObj = json.getJSONArray("product"); // JSON Array
// get first product object from JSON Array
JSONObject product = productObj.getJSONObject(0);
// product with this pid found
// imageview
imageVw = (ImageView) findViewById(R.id.imageView1);
// display data in imageview
//imageStr = "http://somesite.com/images/" + product.getString("imagefile");
imageStr = "file://somesite.com/images/" + product.getString("imagefile");
//imgUri=Uri.parse("file:///data/data/MYFOLDER/myimage.png");
//imgUri=Uri.parse(imageStr);
//imageVw.setImageURI(imgUri);
imageVw.setImageBitmap(BitmapFactory.decodeFile(imageStr));

You can do something like this if you want to get the Bitmap of the image stored on the web. I personally use the library called ImageDownloader. The library is simple to use.
You have to understand that "A URL is a URI but a URI is not a URL. A URL is a specialization of URI that defines the network location of a specific representation for a given resource." so, if your file location is http then you need to make the function like below to get the Bitmap. I use ImageDownloader library because it runs its own thread and also manages some caches for faster image downloads.
private Bitmap getImageBitmap(String url) {
Bitmap bm = null;
try {
URL aURL = new URL(url);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
} catch (IOException e) {
Log.e(TAG, "Error getting bitmap", e);
}
return bm;
}

BitmapFactory returns null

I am working on an application where I am getting an image from the web server.
I need to save that image in a sqlite database. Maybe it will be saved in a byte[]; I have done this way, taking the datatype as blob, and then retrieving the image from db and showing at imageview.
I am stuck somewhere, however: I am getting null when I decodefrom bytearray
The code I have used is:
InputStream is = null;
try {
URL url = null;
url = new URL(http://....);
URLConnection ucon = null;
ucon = url.openConnection();
is = ucon.getInputStream();
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
BufferedInputStream bis = new BufferedInputStream(is);
ByteArrayBuffer barb = new ByteArrayBuffer(128);
int current = 0;
try {
while ((current = bis.read()) != -1) {
barb.append((byte) current);
} catch (IOException e) {
e.printStackTrace();
}
byte[] imageData = barb.toByteArray();
Then I have inserted imageData in to the db..
To retrieve the image:
byte[] logo = c.getBlob(c.getColumnIndex("Logo_Image"));
Bitmap bitmap = BitmapFactory.decodeByteArray(logo, 0, logo.length);
img.setImageBitmap(bitmap);
But I am getting the error:
Bitmap bitmap is getting null.

Sometimes, It happens, when your byte[] not decode properly after retrieving from database as blob type.
So, You can do like this way, Encode - Decode,
Encode the image before writing to the database:
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
mBitmap.compress(Bitmap.CompressFormat.JPEG, THUMB_QUALITY, outputStream);
mByteArray = outputStream.toByteArray(); // write this to database as blob
And then decode it like the from Cursor:
ByteArrayInputStream inputStream = new ByteArrayInputStream(cursor.getBlob(columnIndex));
Bitmap mBitmap = BitmapFactory.decodeStream(inputStream);
Also, If this not work in your case, then I suggest you to go on feasible way..
Make a directory on external / internal storage for your application
images.
Now store images on that directory.
And store the path of those image files in your database. So you
don't have a problem on encoding-decoding of images.

How can I convert response json string image into a displayable image

My final year project requires me to develop a mobile application which fetches a number of Json values from a server. This is my first experience in android development but sure learned something’s and enjoyed the experience.
I have managed to develop the following.
1-a json parser class which fetches the value.
2-a class which displays these values.
3-a database where I store the json response.
However I'm one step away from completing my project, I cannot display the response string image address as real images (shame on me).
I need to do the following.
1- Parse the string path of the image and display the response as image.
I have spent most of my time trying to find the solution on the web, stack overflow. But no luck so far.
I need to do something like this in order to display these images together with the text descriptions.
I have now reached the cross roads and my knowledge has been tested.Is what i'm trying to do here posible?.
Who can show me the way? ,to this outstanding platform.

if you have the image url as a string, you can load and save the image using something like this:
try {
Bitmap bitmap = null;
File f = new File(filename);
InputStream inputStream = new URL(url).openStream();
OutputStream outputStream = new FileOutputStream(f);
int readlen;
byte[] buf = new byte[1024];
while ((readlen = inputStream.read(buf)) > 0)
outputStream.write(buf, 0, readlen);
outputStream.close();
inputStream.close();
bitmap = BitmapFactory.decodeFile(filename);
return bitmap;
} catch (Exception e) {
return null;
}
For saving, make sure you have appropriate permissions if you're going to save to sdcard.
if you just want to load the image (without saving):
Bitmap bm = null;
try {
URL aURL = new URL(url);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
} catch (IOException e) {
Log.e(TAG, "Error getting bitmap", e);
}
return bm;
Just make sure you fetch the image in a separate thread or using AsyncTask or else you'll get ANRs!

you can try this ImageDownloader class from google. It´s works nice :)
Is an AsynkTask that handle the download and set the bitmap to an ImageView.
ImageDownloader
Usage:
private final ImageDownloader mDownload = new ImageDownloader();
mDownload.download("URL", imageView);

Android : Getting this error while downloading image from remote server: SkImageDecoder::Factory returned null

I am trying to download images from a remote server, the number of images downloaded is 30. The code i am using to download image is as below. Some images download successfully and some images don't download and raises the above exception. What might be the problem.
public static Bitmap loadBitmap(String url)
{
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(new URL(url).openStream(), 4*1024);
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, 4 * 1024);
int byte_;
while ((byte_ = in.read()) != -1)
out.write(byte_);
out.flush();
final byte[] data = dataStream.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
//options.inSampleSize = 1;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,options);
} catch (IOException e) {
Log.e("","Could not load Bitmap from: " + url);
} finally {
try{
in.close();
out.close();
}catch( IOException e )
{
System.out.println(e);
}
}
return bitmap;
}

Please look on my this post
Image download code works for all image format, issues with PNG format rendering

In my case I solved this error with encode the url
Because image url that i wanted to download has the Persian letters(or other Unicode character) in it
So I replaced all Persian characters with encoded UTF-8 letters