I have a method where I would download an image from a folder based on the link passed into the AsyncMethod
I have since made some changes and now the image resides on the database. I am having a little problem editing my downloadAsyn Task as it no longer receives a link but instead a long string of characters (BLOB from the database).
I have pasted my code below, and is trying to find assistance in assigning cImg1 the bitmap to display my image.
Thank you
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];// this parameter once had url of image
//but now it has the image bitmap.
Bitmap cImg1= null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
// cImg1= BitmapFactory.decodeStream(in);
cImg1=urldisplay;//Assign strings to BitMap?
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return cImg1;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
Below code will be worked fine.
public class DownloadImageTask extends AsyncTask<String, Integer, Bitmap> {
Context _context;
ImageView _imageView;
private OnResponseListener _responder;
private String _errorMessage;
public DownloadImageTask(ImageView bmImage, OnResponseListener responseListener) {
this._imageView = bmImage;
_context = bmImage.getContext();
_responder = responseListener;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
protected Bitmap doInBackground(String... urls) {
int count;
String urlDisplay = urls[0];
Bitmap bitmap = null;
try {
InputStream in = new java.net.URL(urlDisplay).openStream();
BitmapFactory.Options options = new BitmapFactory.Options(); options.inPurgeable = true; options.inInputShareable = true;
bitmap = BitmapFactory.decodeStream(in, null, options);
URLConnection urlConnection = new java.net.URL(urlDisplay).openConnection();
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
int lengthOfFile = urlConnection.getContentLength();
byte data[] = new byte[1024];
long total = 0;
while ((count = inputStream.read(data)) != -1) {
total += count;
int progress = (int) total * 100 / lengthOfFile;
publishProgress(progress);
}
} catch (Exception e) {
_errorMessage = e.getMessage();
e.printStackTrace();
}
return bitmap;
}
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
}
protected void onPostExecute(Bitmap result) {
if (result != null){
_responder.onSuccess(result);
}
else
_responder.onFailure(_errorMessage);
}
public interface OnResponseListener {
void onSuccess(Bitmap result);
void onFailure(String message);
}
}
Related
I'm trying to display this transparent image in a ImageView.
I download and set the image with this class:
public class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
private String TAG = "DownloadImageTask";
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.d(TAG, e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
Unfortunately the background gets purple. Why does it get purple and how do I solve this?
Not a solution, but more like a fix.
I created a mutable bitmap and changed the colors.
Bitmap copy = result.copy(Bitmap.Config.ARGB_8888, true);
int [] allpixels = new int [ copy.getHeight()*copy.getWidth()];
copy.getPixels(allpixels, 0, copy.getWidth(), 0, 0, copy.getWidth(), copy.getHeight());
for(int i =0; i < copy.getHeight() * copy.getWidth(); i++)
{
if( allpixels[i] == Color.MAGENTA)
{
allpixels[i] = Color.TRANSPARENT;
}
}
copy.setPixels(allpixels, 0, copy.getWidth(), 0, 0, copy.getWidth(), copy.getHeight());
bmImage.setImageBitmap(copy);
I want to take the image from a URL and set is as the background of my RelativeLayout. I use the AsyncTask and try to create a Drawable from BitmapDrawable. But I get a NullPointerException and can't seem to figure out why?
class DownloadBackgroundTask extends AsyncTask<String, Void, Bitmap> {
RelativeLayout bmImage;
View vi;
public DownloadBackgroundTask(RelativeLayout bmImage, View vi) {
this.bmImage = bmImage;
this.vi = vi;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
if (result != null)
{
// null pointer exception here
Drawable d = new BitmapDrawable(vi.getContext().getResources(), result);
bmImage.setBackground(d);
}
else
{
bmImage.setBackgroundResource(R.drawable.logo);
}
}
}
onCreateView():
RelativeLayout rl = (RelativeLayout) rootView.findViewById(R.id.RelativeLayout1);
new DownloadBackgroundTask(rl, rootView).execute("http://pctechmag.com/wp-content/uploads/2012/10/fifa13_messi.jpg");
I have an Async running to get data from a page I've created. It get's the text just fine, but when I try and get the image from the image src via another class the app force closes. Here is the code that it force closes on:
public class FullReportActivity extends NavigationActivity {
private TextView textView;
private String url = "http://www.backcountryskiers.com/sac/sac-full.html";
private ImageView ivDangerRose;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// tell which region this covers
getSupportActionBar().setSubtitle("...from Sierra Avalanche Center");
setContentView(R.layout.activity_fullreport);
textView = (TextView) findViewById(R.id.todaysReport);
ivDangerRose = (ImageView) findViewById(R.id.dangerRose);
fetcher task = new fetcher();
task.execute();
}
// GET THE IMAGE and RETURN IT
public static Bitmap getBitmapFromURL(String src) {
try {
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
class fetcher extends AsyncTask<String, Void, String> {
private ProgressDialog dialog = new ProgressDialog(
FullReportActivity.this);
private Document doc = null;
private Document parse = null;
private String results = null;
private String reportDate = null;
private Bitmap bimage = null;
#Override
protected String doInBackground(String... params) {
try {
doc = Jsoup.connect(url).get();
Log.e("Jsoup", "...is working...");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("Exception", e.getMessage());
}
parse = Jsoup.parse(doc.html());
results = doc.select("#fullReport").outerHtml();
Element dangerRoseImg = doc.getElementById("reportRose")
.select("img").first();
String dangerRoseSrc = dangerRoseImg.absUrl("src");
Log.i("Report Rose IMG", dangerRoseSrc);
bimage = getBitmapFromURL(dangerRoseSrc);
ivDangerRose.setImageBitmap(bimage);
return results;
}
#Override
protected void onPostExecute(String result) {
dialog.dismiss();
// smooth out the long scrolling...
textView.setMovementMethod(ScrollingMovementMethod.getInstance());
reportDate = parse.select("#reportDate").outerHtml();
textView.setText(Html.fromHtml(reportDate + results));
textView.setPadding(30, 20, 20, 10);
}
#Override
protected void onPreExecute() {
dialog.setMessage("Loading Full Report from the Sierra Avalanche Center...");
dialog.show();
}
}
}
I have run this Async alone to get the image like so without a force close and I don't understand what i am doing different besides calling the method:
public class MainActivity extends Activity {
public String durl = "http://www.sierraavalanchecenter.org/dangerrose.png?a=2955";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new DownloadImageTask((ImageView) findViewById(R.id.dangerrose))
.execute(durl);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap drose = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
drose = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return drose;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
}
This class gets the image src and creates a bitmap and puts it into an ImageView, what is different here than on my first class???
Frustrated.
You can not modify UI from background thread.
move ivDangerRose.setImageBitmap(bimage); in onPostExecute
In the method doInBackground
remove --> ivDangerRose.setImageBitmap(bimage);
as you can't modify UI in background process.
If you still want you can try runOnUiThread Method
In doInBackground() we should not access the content of activity.
im fetching an image from internet using the below code using an Async task,But the bitmp returns from the function is always null.
private Bitmap asyncTaskFetchImage(final String imgeurl) {
// TODO Auto-generated method stub
new AsyncTask<Object, Object, Object>() {
#Override
protected void onPreExecute() {
progress_Dialog = ProgressDialog.show(this, "", "Loading");
}
#Override
protected Object doInBackground(Object... params) {
// TODO Auto-generated method stub
try
{
toSendBg=LoadImageFromURL(imgeurl);
System.gc();
return 0;
}
catch (Exception e) {
e.printStackTrace();
}
return 0;
}
#Override
protected void onPostExecute(Object result) {
if (progress_Dialog != null) {
progress_Dialog.dismiss();
}
}
}.execute();
return toSendBg;
}
Is this the exact way to return value from an Asyntask?
Try below code to download image from web using AsyncTask and display in imageview.
public class MainActivity extends Activity {
ImageView mImgView1;
static Bitmap bm;
ProgressDialog pd;
String imageUrl = "https://www.morroccomethod.com/components/com_virtuemart/shop_image/category/resized/Trial_Sizes_4e4ac3b0d3491_175x175.jpg";
BitmapFactory.Options bmOptions;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mImgView1 = (ImageView) findViewById(R.id.mImgView1);
pd = ProgressDialog.show(MainActivity.this, "Aguarde...",
"Carregando...");
new ImageDownload().execute("");
}
public class ImageDownload extends AsyncTask<String, Void, String> {
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
bmOptions = new BitmapFactory.Options();
bmOptions.inSampleSize = 1;
loadBitmap(imageUrl, bmOptions);
return imageUrl;
}
protected void onPostExecute(String imageUrl) {
pd.dismiss();
if (!imageUrl.equals("")) {
mImgView1.setImageBitmap(bm);
} else {
Toast.makeText(MainActivity.this,
"Não foi possível obter resultados", Toast.LENGTH_LONG)
.show();
}
}
}
public static Bitmap loadBitmap(String URL, BitmapFactory.Options options) {
InputStream in = null;
try {
in = OpenHttpConnection(URL);
bm = BitmapFactory.decodeStream(in, null, options);
in.close();
} catch (IOException e1) {
}
return bm;
}
private static InputStream OpenHttpConnection(String strURL)
throws IOException {
InputStream inputStream = null;
URL url = new URL(strURL);
URLConnection conn = url.openConnection();
try {
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setRequestMethod("GET");
httpConn.connect();
if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
inputStream = httpConn.getInputStream();
}
} catch (Exception ex) {
}
return inputStream;
}
}
private Bitmap asyncTaskFetchImage(final String imgeurl) {
Bitmap bmp=null;
new AsyncTask<Object, Object, Object>() {
...
and in your doInBackground method change return to
return toSendBg;
and
#Override
protected void onPostExecute(Object result) {
if (progress_Dialog != null) {
progress_Dialog.dismiss();
bmp=(Bitmap)result;
}
}
}.execute();
return bmp;
Try this..,.
How do I replace the following lines of code with an Asynctask ?
How do you "get back" the Bitmap from the Asynctask ? Thank you.
ImageView mChart = (ImageView) findViewById(R.id.Chart);
String URL = "http://www...anything ...";
mChart.setImageBitmap(download_Image(URL));
public static Bitmap download_Image(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("Hub","Error getting the image from server : " + e.getMessage().toString());
}
return bm;
//---------------------------------------------------
}
I thought about something like this :
replace :
mChart.setImageBitmap(download_Image(graph_URL));
by something like :
mChart.setImageBitmap(new DownloadImagesTask().execute(graph_URL));
and
public class DownloadImagesTask extends AsyncTask<String, Void, Bitmap> {
#Override
protected Bitmap doInBackground(String... urls) {
return download_Image(urls[0]);
}
#Override
protected void onPostExecute(Bitmap result) {
mChart.setImageBitmap(result); // how do I pass a reference to mChart here ?
}
private Bitmap download_Image(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("Hub","Error getting the image from server : " + e.getMessage().toString());
}
return bm;
//---------------------------------------------------
}
}
but How do I pass a reference to mChart in onPostExecute(Bitmap result) ???
Do I need to pass it with the URL in some way ?
I would like to replace all my lines of code :
mChart1.setImageBitmap(download_Image(URL_1));
mChart2.setImageBitmap(download_Image(URL_2));
with something similar ... but in Asynctask way !
mChart1.setImageBitmap(new DownloadImagesTask().execute(graph_URL_1));
mChart2.setImageBitmap(new DownloadImagesTask().execute(graph_URL_2));
Is there an easy solution for this ?
Do I get something wrong here ?
If there is no good reason to download the image yourself then I would recommend to use Picasso.
Picasso saves you all the problems with downloading, setting and caching images.
The whole code needed for a simple example is:
Picasso.with(context).load(url).into(imageView);
If you really want to do everything yourself use my older answer below.
If the image is not that big you can just use an anonymous class for the async task.
This would like this:
ImageView mChart = (ImageView) findViewById(R.id.imageview);
String URL = "http://www...anything ...";
mChart.setTag(URL);
new DownloadImageTask.execute(mChart);
The Task class:
public class DownloadImagesTask extends AsyncTask<ImageView, Void, Bitmap> {
ImageView imageView = null;
#Override
protected Bitmap doInBackground(ImageView... imageViews) {
this.imageView = imageViews[0];
return download_Image((String)imageView.getTag());
}
#Override
protected void onPostExecute(Bitmap result) {
imageView.setImageBitmap(result);
}
private Bitmap download_Image(String url) {
...
}
Hiding the URL in the tag is a bit tricky but it looks nicer in the calling class if you have a lot of imageviews that you want to fill this way. It also helps if you are using the ImageView inside a ListView and you want to know if the ImageView was recycled during the download of the image.
I wrote if you Image is not that big because this will result in the task having a implicit pointer to the underlying activity causing the garbage collector to hold the whole activity in memory until the task is finished. If the user moves to another screen of your app while the bitmap is downloading the memory can't be freed and it may make your app and the whole system slower.
Try this code:
ImageView myFirstImage = (ImageView) findViewById(R.id.myFirstImage);
ImageView mySecondImage = (ImageView) findViewById(R.id.mySecondImage);
ImageView myThirdImage = (ImageView) findViewById(R.id.myThirdImage);
String URL1 = "http://www.google.com/logos/2013/estonia_independence_day_2013-1057005.3-hp.jpg";
String URL2 = "http://www.google.com/logos/2013/park_su-geuns_birthday-1055005-hp.jpg";
String URL3 = "http://www.google.com/logos/2013/anne_cath_vestlys_93rd_birthday-1035005-hp.jpg";
myFirstImage.setTag(URL1);
mySecondImage.setTag(URL2);
myThirdImage.setTag(URL3);
new DownloadImageTask.execute(myFirstImage);
new DownloadImageTask.execute(mySecondImage);
new DownloadImageTask.execute(myThirdImage);
public class DownloadImagesTask extends AsyncTask<ImageView, Void, Bitmap> {
ImageView imageView = null;
#Override
protected Bitmap doInBackground(ImageView... imageViews) {
this.imageView = imageViews[0];
return download_Image((String)imageView.getTag());
}
#Override
protected void onPostExecute(Bitmap result) {
imageView.setImageBitmap(result);
}
private Bitmap download_Image(String url) {
Bitmap bmp =null;
try{
URL ulrn = new URL(url);
HttpURLConnection con = (HttpURLConnection)ulrn.openConnection();
InputStream is = con.getInputStream();
bmp = BitmapFactory.decodeStream(is);
if (null != bmp)
return bmp;
}catch(Exception e){}
return bmp;
}
}
you can create a class say..BkgProcess which contains an inner class that extends AsyncTask. while instantiating BkgProcess pass the context of your Activity class in BkgProcess constructor. for eg:
public class BkgProcess {
String path;
Context _context;
public Download(Downloader downloader, String path2){
this.path = path2;
_context = downloader;
}
public void callProgressDialog(){
new BkgProcess().execute((Void)null);
}
class Downloads extends AsyncTask<Void, Void, Boolean> {
private ProgressDialog dialog = new ProgressDialog(_context);
protected void onPreExecute(){
dialog.setMessage("Downloading image..");
dialog.show();
}
protected void onPostExecute(Boolean success) {
dialog.dismiss();
if(success)
Toast.makeText(_context, "Download complete", Toast.LENGTH_SHORT).show();
}
#Override
protected Boolean doInBackground(Void... params) {
return(startDownload(path));
}
public boolean startDownload(String img_url) {
// download img..
return true;
}
}
}
from your activity class..
BkgProcess dwn = new BkgProcess (Your_Activity_class.this, img_path);
dwn.callProgressDialog();
This will get you images of any size...
if you dont want the progress dialog just comment the codes in onPreExecute();
for(int i = 0 ; i < no_of_files ; i++ )
new FetchFilesTask().execute(image_url[i]);
private class FetchFilesTask extends AsyncTask<String, Void, Bitmap> {
private ProgressDialog dialog = new ProgressDialog(FileExplorer.this);
Bitmap bitmap[];
protected void onPreExecute(){
dialog.setMessage("fetching image from the server");
dialog.show();
}
protected Bitmap doInBackground(String... args) {
bitmap = getBitmapImageFromServer();
return bitmap;
}
protected void onPostExecute(Bitmap m_bitmap) {
dialog.dismiss();
if(m_bitmap != null)
//store the images in an array or do something else with all the images.
}
}
public Bitmap getBitmapImageFromServer(){
// fetch image form the url using the URL and URLConnection class
}